W325A-LX - Console Moxa - Free user manual and instructions

Product Type	Wireless Embedded Computer
Model	W325A-LX
Brand	Moxa
Operating System	Linux (Kernel 2.6.x)
CPU	ARM9-based, 400 MHz
Memory	256 MB RAM, 256 MB Flash
Wireless	IEEE 802.11a/b/g/n, 2.4/5 GHz
Ethernet	1 x 10/100 Mbps RJ45
Serial Ports	2 x RS-232/422/485
Power Input	12 to 48 VDC
Power Consumption	6 W (max)
Dimensions	100 x 70 x 30 mm
Weight	200 g
Operating Temperature	-10 to 60°C
Storage Temperature	-20 to 80°C
Humidity	5 to 95% non-condensing
Protection Rating	IP30
Certifications	CE, FCC
Maintenance	Clean with a dry cloth; avoid liquids
Safety	Use only recommended power supply; disconnect before cleaning
Spare Parts	Contact Moxa support
Repairability	Not user-serviceable; contact authorized service

Frequently Asked Questions - W325A-LX Moxa

How do I reset the W325A-LX to factory defaults?

Press and hold the reset button located near the power connector for at least 5 seconds until the status LED blinks rapidly. The device will reboot with factory settings.

What power supply is recommended for the W325A-LX?

A DC power supply with output voltage between 12 and 48 VDC and a minimum current of 1A is recommended. Use a regulated power supply with overvoltage protection.

How do I connect to the W325A-LX via serial console?

Connect a serial cable to the console port (RS-232) with the following settings: 115200 baud, 8 data bits, no parity, 1 stop bit. Use terminal software like PuTTY.

Can I use the W325A-LX outdoors?

The device has an IP30 rating, meaning it is protected against tools and small wires but not against water. Use in a dry, sheltered location or install in an enclosure.

How do I configure Wi-Fi on the W325A-LX?

Access the web interface via Ethernet, go to Network Settings > Wireless, and configure SSID, security type (WPA2-PSK recommended), and password. The device supports 2.4 GHz and 5 GHz bands.

What is the default username and password for the W325A-LX?

The default credentials are admin for both username and password. Change them immediately after first login for security.

How do I update the firmware on the W325A-LX?

Download the latest firmware from Moxa's website. In the web interface, go to System > Firmware Update, upload the .bin file, and follow the prompts. Do not power off during the update.

What is the operating temperature range of the W325A-LX?

The device can operate in temperatures from -10 to 60°C. For extended temperature ranges, refer to the product datasheet.

How do I mount the W325A-LX?

The device supports DIN rail mounting. Attach the mounting clip to the back panel, then clip onto a standard 35 mm DIN rail. For wall mounting, use the optional bracket.

What should I do if the W325A-LX does not boot?

Check the power supply (12-48 VDC) and ensure the power LED is lit. Try a hard reset by disconnecting power, waiting 10 seconds, and reconnecting. If still not booting, contact Moxa support.

USER MANUAL W325A-LX Moxa

W315A/ 325A Linux User's Manual

First Edition, August 2010

www.moxa.com/product

MOXA®

© 2010 Moxa Inc. All rights reserved. Reproduction without permission is prohibited.

W315A/ 325A Linux User's Manual

The software described in this manual is furnished under a license agreement and may be used only in accordance with the terms of that agreement.

Copyright Notice

Copyright © 2010 Moxa Inc.

All rights reserved.

Reproduction without permission is prohibited.

Trademarks

The MOXA logo is a registered trademark of Moxa Inc.

All other trademarks or registered marks in this manual belong to their respective manufacturers.

Disclaimer

Information in this document is subject to change without notice and does not represent a commitment on the part of Moxa.

Moxa provides this document as is, without warranty of any kind, either expressed or implied, including, but not limited to, its particular purpose. Moxa reserves the right to make improvements and/or changes to this manual, or to the products and/or the programs described in this manual, at any time.

Information provided in this manual is intended to be accurate and reliable. However, Moxa assumes no responsibility for its use, or for any infringements on the rights of third parties that may result from its use.

This product might include unintentional technical or typographical errors. Changes are periodically made to the information herein to correct such errors, and these changes are incorporated into new editions of the publication.

Technical Support Contact Information

www.moxa.com/support

Moxa Americas

Toll-free: 1-888-669-2872

Tel: [phone]

Fax: [phone]

Moxa Europe

Tel: [phone]

Fax: [phone]

Moxa China (Shanghai office)

Toll-free: 800-820-5036

Tel: [phone]

Fax: [phone]

Moxa Asia-Pacific

Software Architecture....1-2

Journaling Flash File System (JFFS2) 1-3

Software Package 1-4

2. Getting Started.... 2-1

Powering on the W315A/325A 2-2

Connecting the W315A/325A to a PC....2-2

Serial Console 2-2

SSH Console 2-3

Configuring the Ethernet Interface 2-3

Modifying Network Settings with the Serial Console 2-3

Modifying Network Settings over the Network 2-4

GPRS Networks 2-4

Setting Up the Wireless Module 2-4

Configuring the SIM Card....2-4

Entering the PIN Code 2-5

Verifying the SIM Card Status 2-5

Enabling or Disabling PIN Code Authentication....2-5

Changing the PIN Code....2-6

Unlocking the SIM Card 2-6

Configuring Your APN List 2-7

Connecting to the Internet 2-8

Reconnecting to the Internet....2-8

Disconnecting from the Internet 2-9

Detecting an Internet Connection Error 2-9

Sending and Reading an SMS Message 2-9

Deleting an SMS Message 2-10

SD Socket for Storage Expansion....2-10

Test Program—Developing Hello.c....2-11

Installing the Tool Chain (Linux)....2-11

Checking the Flash Memory Space....2-11

Compiling Hello.c 2-12

Uploading and Running the "Hello" Program 2-13

Developing Your First Application....2-13

Testing Environment 2-13

Compiling tcps2.c....2-14

Uploading and Running the "tcps2-release" Program 2-15

Summary of the Testing Procedure 2-17

3. Managing Embedded Linux 3-1

System Version Information....3-2

System Image Backup....3-2

Upgrading the Firmware 3-2

Loading Factory Defaults 3-4

Enabling and Disabling Daemons 3-4

Starting a Program Automatically at Run-Level....3-6

Adjusting the System Time 3-7

Setting the Time Manually 3-7

NTP Client 3-8

Updating the Time Automatically 3-8

Cron—Daemon for Executing Scheduled Commands....3-9

4. Managing Communications.... 4-1

Telnet/FTP 4-2

DNS 4-2

Web Service—Apache 4-3

Installing PHP for Apache Web Server 4-4

IPTABLES....4-7

Observe and Erase Chain Rules....4-9

Define Policy for Chain Rules....4-9

Append or Delete Rules....4-10

NAT 4-10

NAT Example 4-11

Enabling NAT at Bootup....4-11

Dial-up Service—PPP 4-12

How to Check the Connection ....4-13

Setting up a Machine for Incoming PPP Connections 4-14

PPPoE....4-15

GPRS Connection 4-17

Configuring the options for pppd 4-17

Configuring the AT commands 4-18

Example: Selecting the radio band 4-18

NFS (Network File System) 4-18

Setting up the W315A/325A as an NFS Client 4-19

Mail 4-19

SNMP 4-19

1. Development Tool Chains.... 5-1

Linux Tool Chain 5-2

Steps for Installing the Linux Tool Chain....5-2

Compiling an Application 5-2

On-Line Debugging with GDB....5-3

1. Programmer's Guide 6-1

Before Programming Your Embedded System 6-2

Caution Required when Using File Systems....6-2

Using a RAM File System instead of a Flash File System 6-2

Flash Memory Map 6-2

Device API 6-2

RTC (Real Time Clock) 6-3

Buzzer....6-3

WDT (Watch Dog Timer) 6-3

UART 6-6

C Library 6-7

1. Software Lock 7-1

A. System Commands.... A-1

Common Linux Utility Commands ......A-2

File Manager....A-2

Editor A-2

Network A-2

Process....A-2

Other A-3

Special Moxa Utilities ......A-3

The W315A/325A series of wireless RISC-based embedded computers feature a GSM/GPRS module, RS-232/422/485 serial ports, and an Ethernet port in a small, rugged chassis, and come with an SD slot for external storage expansion.

The W315A/325A series embedded computers are ideal for diverse, machine-to-machine embedded applications. The computers enable the wireless operation of network and serial devices that are traditionally wired, and can handle transparent data transfers, numerical computing, protocol conversion, data processing, and even data encryption. The W315A/325A will make it easier to build embedded systems for distributed peer-to-peer communication, turn wired devices into wireless devices, and introduce higher mobility and more intelligence to your system. In this chapter, we cover the various capabilities of the W315A/325A series embedded computers.

The following topics are covered in this chapter:

Overview
□ Software Architecture

▶ Journaling Flash File System (JFFS2)
Software Package

Overview

The W315A/325A wireless embedded computers come with a quad band 850/900/1800/1900 MHz GSM/GPRS module built in for long-range communications.

The computers use a Moxa ART 192 Mhz RISC CPU. Unlike the X86 CPU, which uses a CISC design, the RISC architecture and modern semiconductor technology provide these embedded computers with a powerful computing engine and communication functions, but without generating a lot of heat. A 16 MB NOR Flash ROM and on-board 32 MB SDRAM give you enough memory to install your application software directly on the embedded computer. In addition, a LAN port is built right into the RISC CPU. This network capability, in combination with the ability to control serial devices, makes the W300 Series ideal as communication platforms for data acquisition and industrial control applications.

The pre-installed Linux operating system (OS) provides an open software operating system for your software program development. Software written for desktop PCs can be easily ported to the computer with a GNU cross compiler, without needing to modify the source code. The OS, device drivers (e.g., serial and buzzer control), and your own applications, can all be stored in the NOR Flash.

Software Architecture

The Linux operating system that is pre-installed in the W315A/325A follows the standard Linux architecture, making it easy to accept programs that follow the POSIX standard. Program porting is done with the GNU Tool Chain provided by Moxa. In addition to Standard POSIX APIs, device drivers for USB storage, buzzer and Network controls, and UART are also included with the Linux OS.

graph TD
    A["OS Kernel"] --> B["Hardware"]
    B --> C["Microkernel"]
    C --> D["Device Driver"]
    D --> E["Protocol Stack"]
    E --> F["API"]
    F --> G["AP"]

    subgraph OS_Kernel
        H["RS-232/422/485, Ethernet, Flash, USB"]
    end

    subgraph File_System
        I["File System"]
        J["RTC, USB, UART"]
    end

    style OS_Kernel fill:#f9f9f9,stroke:#333
    style File_System fill:#ffcccc,stroke:#333

The W315A/325A's built-in Flash ROM is partitioned into Boot Loader, Linux Kernel, Root File System, and User directory partitions.

In order to prevent user applications from crashing the Root File System, the W315A/325A computers use a specially designed Root File System with Protected Configuration for emergency use. This Root File System comes with serial and Ethernet communication capability for users to load the Factory Default Image file. The user directory saves the user's settings and applications.

To improve system reliability, the W315A/325A has a built-in mechanism that prevents the system from crashing. When the Linux kernel boots up, the kernel will mount the root file system for read only, and then enable services and daemons. During this time, the kernel will start searching for system configuration parameters with rc or inittab.

Normally, the kernel uses the Root File System to boot up the system. The Root File System is protected, and cannot be changed by the user. This type of setup creates a "safe" zone.

For more information about the memory map and programming, refer to Chapter 6, Programmer's Guide.

Journaling Flash File System (JFFS2)

The Root File System and User Directory in the flash memory are formatted with the Journaling Flash File System (JFFS2). The formatting process places a compressed file system in the flash memory. This operation is transparent to the user.

The Journaling Flash File System (JFFS2), which was developed by Axis Communications in Sweden, puts a file system directly on the flash, instead of emulating a block device. It is designed for use on flash-ROM chips and recognizes the special write requirements of a flash-ROM chip. JFFS2 implements wear-leveling to extend the life of the flash disk, and stores the flash directory structure in the RAM. A log-structured file system is maintained at all times. The system is always consistent, even if it encounters crashes or improper power-downs, and does not require fsck (file system check) on boot-up.

JFFS2 is the newest version of JFFS. It provides improved wear-leveling and garbage-collection performance, improved RAM footprint and response to system-memory pressure, improved concurrency and support for suspending flash erases, marking of bad sectors with continued use of the remaining good sectors (enhancing the write-life of the devices), native data compression inside the file system design, and support for hard links.

The key features of JFFS2 are:

• Targets the Flash ROM Directly
- Robustness
• Consistency across power failures
- Explicit wear leveling
- Transparent compression

• No integrity scan (fsck) is required at boot time after normal or abnormal shutdown

Although JFFS2 is a journaling file system, it may not prevent the loss of data. The file system will remain in a consistent state across power failures and will always be mountable. However, if the board is powered down during a write then the incomplete write will be rolled back on the next boot, but writes that have already been completed will not be affected.

Additional information about JFFS2 is available at:

http://sources.redhat.com/jffs2/jffs2.pdf

http://developer.axis.com/software/jffs/

http://www.linux-mtd.infradead.org/

Software Package

Boot Loader	Moxa private (V1.2)
Kernel Linux 2.6.9
Protocol Stack	ARP, PPP, CHAP, PAP, IPv4, ICMP, TCP, UDP, DHCP, FTP, SNMP V1/V3, HTTP, NTP, NFS, SMTP, SSH 1.0/2.0, SSL, Telnet, PPPoE, OpenVPN
File System	JFFS2, NFS, Ext2, Ext3, VFAT/FAT
OS shell command Bash
Busybox	Linux normal command utility collection

Utilities

tinylogin login and user manager utility
telnet telnet client program
ftp FTP client program
smtpclient email utility
scp Secure file transfer	Client Program

Daemons

pppd	dial in/out over serial port daemon
egprsagent	Sms/sim/gprs controlling agent
snmpd	snmpd agent daemon
inetd	TCP server manager program
ftpd	ftp server daemon
apache	web server daemon
sshd	secure shell server
openvpn	virtual private network
openssl	open SSL

Linux Tool Chain

Gcc (V3.3.2)	C/C++ PC Cross Compiler
GDB (V5.3)	Source Level Debug Server
Glibc (V2.2.5)	POSIX standard C library

In this chapter, we explain how to connect the W315A/325A, turn on the power, get started programming, and how to use the W315A/325A's other functions.

The following topics are covered in this chapter:

□ Powering on the W315A/325A
☐ Connecting the W315A/325A to a PC

Serial Console

SSH Console

□ Configuring the Ethernet Interface

Modifying Network Settings with the Serial Console
➢ Modifying Network Settings over the Network

□ GPRS Networks
☐ Setting Up the Wireless Module
□ Configuring the SIM Card
☐ Entering the PIN Code
□ Verifying the SIM Card Status
☐ Enabling or Disabling PIN Code Authentication
□ Changing the PIN Code
□ Unlocking the SIM Card
□ Configuring Your APN List
□ Connecting to the Internet
□ Reconnecting to the Internet
☐ Disconnecting from the Internet
□ Detecting an Internet Connection Error
□ Sending and Reading an SMS Message
☐ Deleting an SMS Message
☐ SD Socket for Storage Expansion
□ Test Program—Developing Hello.c

➢ Installing the Tool Chain (Linux)
➢ Checking the Flash Memory Space
▶ Compiling Hello.c
- Uploading and Running the "Hello" Program

☐ Developing Your First Application

Testing Environment
▶ Compiling tcps2.c
- Uploading and Running the "tcp2-release" Program
➢ Summary of the Testing Procedure

Powering on the W315A/ 325A

Connect the SG wire to the shielded contact located on the left of the W315A/325A's top panel, and then power on the computer by connecting it to the power adaptor. It takes about 30 to 60 seconds for the system to boot up. Once the system is ready, the Ready LED will light up.

NOTE

After connecting the W315A/325A to the power supply, it will take about 30 to 60 seconds for the operating system to boot up. The green Ready LED will not turn on until the operating system is ready.

ATTENTION

This product is intended to be supplied by a Listed Power Unit and output marked with "LPS" and rated 12-48 VDC, 1.2 A (minimum requirements).

Connecting the W315A/ 325A to a PC

There are two ways to connect the W315A/325A to a PC: through the serial console port or by SSH Console over the network.

Serial Console

The serial console gives users a convenient way of connecting to the W315A/325A. This method is particularly useful when using the computer for the first time, or when you do not know either of the W315A/325A's two IP addresses.

Use the serial console port settings shown below.

Baudrate 115200	bps
Parity None
Data bits 8
Stop bit 1
Flow Control None
Terminal VT100

Once the connection is established, the following window will open.

SSH Console

The W315A/325A supports an SSH Console to provide users with better security options. Use this option only if you know exactly which IP address has been assigned from your DHCP server; otherwise, you should connect through the serial console and change it to a static IP address before using it.

Windows Users

Click on the link http://www.chiark.greenend.org.uk/\~sgtatham/putty/download.html to download PuTTY (free software) to set up an SSH console for the W315A/325A in a Windows environment. The following figure shows a simple example of the configuration that is required.

Linux Users

From a Linux machine, use the "ssh" command to access the W315A/325A's console utility via SSH.

# ssh 192.168.27.122

Select yes to complete the connection.

[root@localhost root]# ssh 192.168.27.122
The authenticity of host '192.168.27.122 (192.168.27.122)' can't be established.
RSA key fingerprint is 8b:ee:ff:84:41:25:fc:cd:2a:f2:92:8f:cb:1f:6b:2f.
Are you sure you want to continue connection (yes/no)? yes_ 

NOTE SSH provides better security compared to Telnet for accessing the W315A/325A's console utility over the network.

Configuring the Ethernet Interface

The network settings of the W315A/325A can be modified with the serial console, or online over the network.

Modifying Network Settings with the Serial Console

In this section, we use the serial console to configure the network settings of the target computer.

1. Follow the instructions given in a previous section to access the Console Utility of the target computer through the serial console port, and then type #cd /etc/network to change directories.

1. Type #vi interfaces to use vi editor to edit the network configuration file. You can configure the Ethernet ports of the W315A/325A for dynamic (DHCP) IP addresses.
2. After the boot settings of the LAN interface have been modified, issue the following command to activate the LAN settings immediately:

/etc/init.d/networking restart

NOTE After changing the IP settings, use the networking restart command to activate the new IP address.

Modifying Network Settings over the Network

IP settings can be activated over the network, but the new settings will not be saved to the flash ROM without modifying the file / etc/ network/ interfaces.

For example, type the command #ifconfig eth0 192.168.27.125 to change the LAN IP address to 192.168.27.125.

root@Moxa:~# ifconfig eth0 192.168.27.125
root@Moxa:~# _ 

GPRS Networks

The W315A/325A embedded computers include a GSM/GPRS module for wireless communication. The module can be used to transmit data over a GPRS network.

Setting Up the Wireless Module

Before using the W315A/325A, make sure the SIM card is properly installed and the antenna is connected (refer to the W315A/325A Hardware User's Manual for details). Note that the SIM card must be installed when the embedded computer is powered off.

The LED indicators on the front panel can be used to check the signal strength. A process running in the background, called "egprsagent," is responsible for this task.

Configuring the SIM Card

NOTE: Make sure you have the correct PIN code. After three failed attempts to enter the PIN code, the SIM card will be locked, and you will need to use the PUK code to unlock the SIM card. After ten failed attempts to enter the PUK code, the SIM card will be deactivated and will no longer be operable.

Entering the PIN Code

Use the sim_input_pin -p PIN code command to enter the PIN code. For example, type sim_input_pin -p 0000 to enter the PIN code 0000.

To save the PIN code and perform automatic authentication for a GPRS connection, add -s after the PIN code. To disable automatic authentication, remove the system file /etc/chatscripts/cpin.

Verifying the SIM Card Status

Use the sim_get_pin_status command to check the SIM card status.

There are four possible responses:

Ready: Your W315A/325A wireless module is ready to work.

No SIM card: You need to insert the SIM card into the W315A/325A, or your SIM card may not be inserted correctly.

Need PIN code: You need to enter the correct PIN code. See Entering the PIN Code in this section for details.

Need PUK code: You need to enter the PUK code: See Unlocking the SIM Card in this section for details.

Enabling or Disabling PIN Code Authentication

You can enable PIN code authentication to prompt for PIN code authentication whenever the W315A/325A boots up.

Use the sim_enable_pin -e -p PIN code command to enable PIN code authentication. For example, enter sim_enable_ping -e -p 0000 to activate PIN code authentication.

To disable PIN code authentication, use the sim_enable_pin-d -p command.

Changing the PIN Code

Use the sim_change_pin -o old PIN code -n new PIN code command to change the PIN code. For example, enter sim_input_pin -o 0000 -n 1111 to replace an old PIN code, 0000, with a new one, 1111.

Note that you must enable PIN code authentication to change the PIN code.

Unlocking the SIM Card

When your SIM has been locked, you will need to enter the PUK code to unlock your SIM card. Use the sim_unlock -p PUK code -n new PIN code command to unlock your card. Note that when you enter the PUK code, you also need to provide a new PIN code. For example, type sim_unlock -p 80364944 -n 0000.

In this case, 80364944 is the PUK code, and 0000 is the new PIN code. Use this new PIN code the next time the W315A/325A starts.

Configuring Your APN List

Before you start connecting to the Internet, take the following steps to configure the APN list:

1. Check the operator's name by using the egprscmd -t at+ cops? command. However, make sure you have entered a correct PIN code or disabled PIN code authentication so you can check the operator's name.

1. Next, you need to add the operator's name and APN name in the file /etc/ chatscripts/apn_list. In this case, we know that the operator is Chunghwa Teleco. Add this information in the file.

1. If the operator has provided the user and password information, you can edit them in this file.

Connecting to the Internet

To create a connection, use the gprs_connect command.

For detailed command syntax, type gprs_connect -h. While connected, you can use the gprs_connection_status command to check the connection status.

Reconnecting to the Internet

When an internet connection gets disconnected, use the gprs_reconnect -t second command to reconnect. For example, enter gprs_reconnect -t 120 to direct the W315A/325A to attempt to reconnect to the Internet every 120 seconds. If you do not provide the time interval, the default value of 60 seconds will be used.

Use the gprs_reconnect -h command for more details. If you have enabled PIN checking, issue the command sim_input_pin -p xxxx -s to save the PIN code information in the system. Issue the command gprs_disconnect -r to disable the reconnection setting.

Disconnecting from the Internet

To disconnect from the Internet, use the gprs_disconnect command. After a few seconds, the embedded computer will disconnect from the GPRS network. A notification message will NOT be displayed.

Detecting an Internet Connection Error

To diagnose a connection problem, use the gprs_diagnose command. This utility will execute a series of steps to check whether or not the configuration is correct. Most connection problems can be identified with this command.

Sending and Reading an SMS Message

To send an SMS message, use the sms_send_text_msg command. For example, enter sms_send_text_msg -n 0988713219 -t "hello! This is an SMS test." to send the message "hello! This is an SMS test." to the phone number 0988693141.

To read an SMS message, use the sms_read_text_msg -i command. For example, sms_read_text_msg -i 1, will display the first SMS message.

Deleting an SMS Message

To delete an SMS message, use the sms_remove_msg command. For example, the sms_remove_msg -i 1 command will delete the first SMS message.

SD Socket for Storage Expansion

The W315A/325A models have an SD socket for storage expansion. The SD slot allows users to plug in a Secure Digital (SD) memory card compliant with the SD 1.0 standard for up to 1 GB of additional memory space, or a Secure Digital High Capacity (SDHC) memory card compliant with the SD 2.0 standard for up to 16 GB of additional memory space. Refer to the W315A/325A Hardware User's Manual to see how to install the SD card.

After installing an SD card, the SD card will be mounted at /mnt/ sd.

Test Program—Developing Hello.c

In this section, we use the standard "Hello" programming example to illustrate how to develop a program for the W315A/325A. In general, program development involves the following seven steps.

Step 1:

Connect the W315A/325A to a Linux PC.

Step 2:

Install Tool Chain (GNU cross Compiler & glibc).

Step 3:

Set the cross compiler and glibc environment variables.

Step 4:

Code and compile the program.

Step 5:

Download the program to the W315A/325A via FTP or NFS.

Step 6:

Debug the program

If bugs are found, return to Step 4.

If no bugs are found, continue with Step 7.

Step 7:

Back up the user directory (distribute the program to additional W315A/325A units if needed).

graph TD
    A["Laptop"] -->|Cross Compiler| B["Router"]
    C["Penguin 1"] --> B
    D["Penguin 2"] --> B

Installing the Tool Chain (Linux)

The Linux Operating System must be pre-installed in the PC before installing the W315A/325A GNU Tool Chain. Fedora core or compatible versions are recommended. The Tool Chain requires approximately 200 MB of hard disk space on your PC. The W315A/325A Tool Chain software is located on the W315A/325A CD. To install the Tool Chain, insert the CD in your PC and then issue the following commands:

mount /dev/cdrom /mnt/cdrom

sh /mnt/cdrom/tool-chain/linux/install.sh

The Tool Chain will be installed automatically on your Linux PC within a few minutes. Before compiling the program, be sure to set the following path first, since the Tool Chain files, including the compiler, link, library, and include files are located in this directory.

PATH=/usr/local/arm-linux/bin:\$PATH

Setting the path allows you to run the compiler from any directory.

Checking the Flash Memory Space

If the flash memory is full, you will not be able to save data to the Flash ROM. Use the following command to calculate the amount of "Available" flash memory:

/ > df - h

If there isn't enough "Available" space for your application, you will need to delete some existing files. To do this, connect your PC to the W315A/325A with the console cable, and then use the console utility to delete the files from the W315A/325A's flash memory. To check the amount of free space available, look at the directories in the read/write directory /dev/mtdblock3. Note that the directories /home and /etc are both mounted in the directory /dev/mtdblock3.

NOTE If the flash memory is full, you will need to free up some memory space before saving files to the Flash ROM.

Compiling Hello.c

The package CD contains several example programs. Here we use Hello.c as an example to show you how to compile and run your applications. Type the following commands from your PC to copy the files used for this example from the CD to your computer's hard drive:

<h1 id="cd-tmp">cd /tmp/</h1>
<h1 id="mkdir-example">mkdir example</h1>
<h1 id="cp-r">cp -r</h1>
/mnt/cdrom/examples/W321.341.315.325.345_IA240.241_UC-7112PLUS_W315A.W325A/*
/tmp/example 

To compile the program, go to the Hello subdirectory and issue the following commands:

#cd example/hello
#make 

You should receive the following response:

[root@localhost hello]# make
/usr/local/arm-linux/bin/arm-linux-gcc -o hello-release hello.c
/usr/local/arm-linux/bin/arm-linux-strip -s hello-release
/usr/local/arm-linux/bin/arm-linux-gcc -ggdb -o hello-debug hello.c
[root@localhost hello]# _ 

Next, execute hello.exe to generate hello-release and hello-debug, which are described below:

hello-release—an ARM platform execution file (created specifically to run on the W315A/325A)

hello-debug—an ARM platform GDB debug server execution file (see Chapter 5 for details about the GDB debug tool).

NOTE

Since Moxa's tool chain places a specially designed Makefile in the directory / tmp/example/hello, be sure to type the #make command from within that directory. This special Makefile uses the arm-linux-gcc compiler to compile the hello.c source code for the RISC-based environment. If you type the #make command from within any other directory, Linux will use the x86 compiler (for example, cc or gcc).

Refer to Chapter 5 to see a Makefile example.

Uploading and Running the "Hello" Program

Use the following commands to upload hello-release to the W315A/325A via FTP.

1. From the PC, type:

ftp 192.168.3.127

1. Use the bin command to set the transfer mode to Binary mode, and then use the put command to initiate the file transfer:

ftp> bin
ftp> put hello-release 

1. From the W315A/325A, type:

chmod +x hello-release

./hello-release

The word Hello will be printed on the screen.

root@Moxa:~# ./hello-release
Hello 

Developing Your First Application

We use the tcps2 example to illustrate how to build an application. The procedure outlined in the following subsections will show you how to build a TCP server program plus serial port communication that runs on the W315A/325A.

Testing Environment

The tcps2 example demonstrates a simple application program that delivers transparent, bi-directional data transmission between the W315A/325A's serial and Ethernet ports. As illustrated in the following figure, the purpose of this application is to transfer data between PC 1 and the W315A/325A through an RS-232 connection. At the remote site, data can be transferred between the W315A/325A's Ethernet port and PC 2 over an Ethernet connection.

graph TD
    PC1["PC1"] --> RS-232["RS-232"]
    RS-232 --> Ethernet["Ethernet"]
    Ethernet --> PC2["PC2"]

    subgraph PC1
        A["Computer"] --> RS-232
        RS-232 --> Ethernet
    end

    subgraph PC2
        B["Computer"] --> RS-232
        RS-232 --> Ethernet
    end

    TCPS2.c["tcps2.c"] -->|Read serial data| A
    TCPS2.c -->|Send data to PC2| B
    TCPS2.c -->|Write data to PC1| A
    TCPS2.c -->|Receive LAN data| B
    TCPS2.c -->|Serial Rx Buffer| C["Server"]
    TCPS2.c -->|LAN Rx Buffer| D["Server"]

Compiling tcps2.c

The source code for the tcps2 example is located on the CD-ROM at

CD-ROM://examples/W321.341.315.325.345_IA240.241_UC-7112PLUS_W315A.W325A/TCPServer2/tcps2.c. 

Use the following commands to copy the file to a specific directory on your PC. We use the directory

/home/w3x5/1st_application/. Note that you need to copy 3 files Makefile, tcps2.c, tcpsp.c from the CD-ROM to the target directory. 

mount -t iso9660 /dev/cdrom /mnt/cdrom

#cp /mnt/cdrom/examples/W321.341.315.325.345_IA240.241_UC-7112PLUS_W315A.W325A/ 

TCPServer2/tcpsp.c /home/w3x5/1st_application/tcps2.c

#cp /mnt/cdrom/ /home/w3x5/1st_application/tcpsp.c 

#cp /mnt/cdrom/examples/W321.341.315.325.345_IA240.241_UC-7112PLUS_W315A.W325A/ 

TCPServer2/Makefile /home/w3x5/1st_application/Makefile 

Type #make to compile the example code:

You will get the following response, indicating that the example program compiled successfully.

root@server11:/home/w3x5/1st_application

[root@server11 1st_application]# pwd
/home/w3x5/1st_application

[root@server11 1st_application]# 11
total 20
-rw-r-r-- 1 root root 514 Nov 27 11:52 Makefile
-rw-r-r-- 1 root root 4554 Nov 27 11:52 tcps2.c
-rw-r-r-- 1 root root 6164 Nov 27 11:55 tcps2.c

[root@server11 1st_application]# make_
/usr/local/arm-linux/bin/arm-linux-gcc -o tcps2-release tcps2.c
/usr/local/arm-linux/bin/arm-linux-strip -s tcps2-release
/usr/local/arm-linux/bin/arm-linux-gcc -o tcpsp-release tcpsp.c
/usr/local/arm-linux/bin/arm-linux-strip -s tcpsp-release
/usr/local/arm-linux/bin/arm-linux-gcc -ggdb -o tcps2-debug tcps2.c
/usr/local/arm-linux/bin/arm-linux-gcc -ggdb -o tcpsp-debug tcpsp.c

[root@server11 1st_application]# 11
total 92
-rw-r--r-- 1 root root 514 Nov 27 11:52 Makefile
-rwxr-xr-x 1 root root 25843 Nov 27 12:03 tcps2-debug
-rwxr-xr-x 1 root root 4996 Nov 27 12:03 tcps2-release
-rw-r--r-- 1 root root 4554 Nov 27 11:52 tcps2.c
-rwxr-xr-x 1 root root 26823 Nov 27 12:03 tcpsp-debug
-rwxr-xr-x 1 root root 5396 Nov 27 12:03 tcpsp-release
-rw-r--r-- 1 root root 6164 Nov 27 11:55 tcpsp.c

[root@server11 1st_application]# 

Two executable files, tcps2-release and tcps2-debug, are created.

tcps2-release—an ARM platform execution file (created specifically to run on the W315A/325A)

tcps2-debug—an ARM platform GDB debug server execution file (see Chapter 5 for details about the GDB debug tool).

NOTE

If you get an error message at this point, it could be because you neglected to put tcps2.c and tcpsp.c in the same directory. The example Makefile we provide is set up to compile both tcps2 and tcpsp into the same project Makefile. Alternatively, you could modify the Makefile to suit your particular requirements.

Uploading and Running the "tcps2-release" Program

Use the following commands to use FTP to upload tcps2-release to the W315A/325A.

1. From the PC, type:

ftp 192.168.3.127

1. Next, use the bin command to set the transfer mode to Binary, and the put command to initiate the file transfer:

ftp> bin
ftp> cd home
ftp> put tcps2-release 

root@server11:/home/w3x5/1st_application

[root@server11 1st_application]# ftp 192.168.3.127
Connected to 192.168.3.127
220 Moxa FTP server (Version wu-2.6.1(2) Mon Nov 24 12:17:04 CST 2003) ready.
530 Please login with USER and PASS.
530 Please login with USER and PASS.
KERBEROS_V4 rejected as an authentication type
Name (192.168.3.127:root): root
331 Password required for root.
Password:
230 User root logged in.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> bin
200 Type set to I.
ftp> put tcps2-release
local: tcps2-release remote: tcps2-release
277 Entering Passive Mode (192.168.3.127.82.253)
150 Opening BINARY mode data connection for tcps2-release.
226 Transfer complete
4996 bytes sent in 0.00013 seconds (3.9e+04 Kbytes/s)
ftp> ls
227 Entering Passive Mode (192.168.3.127.106.196)
150 Opening ASCII mode data connection for /bin/ls.
-rw---- 1 root root 899 Jun 10 08:11 bash_history
-rw-r--r-- 1 root root 4996 Jun 12 02:15 tcps2-release
226 Transfer complete
ftp> 

1. From the W315A/325A, type:

<h1 id="chmod-x-tcps2-release">chmod +x tcps2-release</h1>
<h1 id="tcps2-release">./tcps2-release &</h1>

192.168.3.127 - PuTTY
root@Moxa:~# ls -al
drwxr-xr-x 2 root root 0 Jun 12 02:14
drwxr-xr-x 15 root root 0 Jan 1 1970
-rw---- 1 root root 899 Jun 10 08:11 .bash_history
-rw-r--r-- 1 root root 4996 Jun 12 02:15 tcps2-release
root@Moxa:~# chmod +x tcps2-release
root@Moxa:~# ls -al
drwxr-xr-x 2 root root 0 Jun 12 02:14
drwxr-xr-x 15 root root 0 Jan 1 1970 

-rw---- 1 root root 899 Jun 10 08:11 .bash_history
-rwxr-xr-x 1 root root 4996 Jun 12 02:15 tcps2-release
root@Moxa:~# 

1. The program should start running in the background. Use the #ps -ef command to check if the tcp2 program is actually running in the background.

ps // use this command to check if the program is running

192.168.3.127 - PuTTY
[1]+ Running ./tcps2-release &
root@Moxa:~# ps -ef
PID Uid VmSize Stat Command
1 root 532 S init [3]
2 root SWN [ksoftirqd/0]
3 root SW< [events/0]
4 root SW< [khelper]
13 root SW< [kblockd/0]
14 root SW [khubd]
24 root SW [pdflush]
25 root SW [pdflush]
27 root SW< [aio/0]
26 root SW [kswapd0]
604 root SW [mtdblockd]
609 root SW [pccardd]
611 root SW [pccardd]
625 root SWN [jffs2_gcd_mtd3]
673 root 500 S /bin/inetd
679 root 3004 S /usr/bin/httpd -k start -d /etc/apache
682 bin 380 S /bin/portmap
685 root 1176 S /bin/sh --login
690 root 464 S /bin/snmpd
694 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
695 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
696 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
697 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
698 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
701 root 352 S /bin/reportip
714 root 1176 S -bash
726 root 436 S /bin/telnetd
727 root 1164 S -bash
728 root 1264 S ./tcps2-release
729 root 1592 S ps -ef
root@Moxa:~# 

NOTE Use the kill -9 command for PID 728 to terminate this program: #kill -9 728

Summary of the Testing Procedure

1. Compile tcps2.c (#make).
2. Upload and run tcps2-release in the background (#./tcps2-release &).
3. Check that the process is running ( #jobs or #ps -ef).
4. Use a serial cable to connect PC1 to the W315A/325A's serial port 1.
5. Use an Ethernet cable to connect PC2 to the W315A/325A.
6. On PC1: If running Windows, use HyperTerminal (38400, n, 8, 1) to open COMn.
7. On PC2: Type #telnet 192.168.3.127 4001.
8. On PC1: Type some text on the keyboard and then press Enter.
9. On PC2: The text you typed on PC1 will appear on PC2's screen.

The testing environment is illustrated in the following figure. However, note that there are limitations to the example program tcps2.c.

graph LR
    subgraph PC1
        A["PC1"] -->|RS-232| B["LAN"]
        C["PC2"] --> D["PC2"]
    end

    subgraph RS-232
        B -->|LAN| D
    end

    subgraph TCPS2.c
        E["Read serial data"] --> F["Serial Rx Buffer"]
        G["Write data to PC1"] --> H["LAN Rx Buffer"]
        I["Send data to PC2"] --> F
        J["Receive LAN data"] --> H
    end

    F <--> H
    F <--> I
    F <--> J

NOTE

The tcps2.c application is a simple example designed to give users a basic understanding of the concepts involved in combining Ethernet communication and serial port communication. However, the example program has some limitations that make it unsuitable for real-life applications.

The serial port is in canonical mode and block mode, making it impossible to send data from the Ethernet side to the serial side (i.e., from PC 2 to PC 1 in the above example).

The Ethernet side will not accept multiple connections.

This chapter includes information about version control, deployment, updates, and peripherals. The information in this chapter will be particularly useful when you need to run the same application on several W315A/325A units.

The following topics are covered in this chapter:

□ System Version Information
□ System Image Backup

Upgrading the Firmware
➢ Loading Factory Defaults

□ Enabling and Disabling Daemons
☐ Starting a Program Automatically at Run-Level
□ Adjusting the System Time

➢ Setting the Time Manually
NTP Client
➢ Updating the Time Automatically

□ Cron—Daemon for Executing Scheduled Commands

System Version Information

To determine the hardware capability of your W315A/325A, and what kind of software functions are supported, check the version numbers of your W315A/325A's hardware, kernel, and user file system. Contact Moxa to determine the hardware version. You will need the Production S/N (Serial number), which is located on the W315A/325A's bottom label.

To check the kernel version, type: #kversion

192.168.3.127 - PuTTY
root@Moxa:~# kversion
W325A Version 1.0
root@Moxa:~# 

NOTE

The kernel version number shown above is for the factory default configuration. If you download and install the latest firmware version from Moxa's website, the new kernel version number will be displayed.

System Image Backup

Upgrading the Firmware

The W315A/325A's bios, kernel, and root file system are combined into one firmware file, which can be downloaded from Moxa's website (www.moxa.com). The name of the file has the form w3x5a-x.x.hfm, in which "x.x" indicates the firmware version (w3x5a-x.x.x.hfm for customized version). To upgrade the firmware, download the firmware file to a PC, and then transfer the file to the W315A/325A through a console port or Telnet console connection.

ATTENTION

Upgrading the firmware will erase all data on the Flash ROM

If you are using the ram disk to store code for your applications, beware that updating the firmware will erase all of the data on the Flash ROM. You should back up your application files and data before updating the firmware.

Since different Flash disks have different sizes, it's a good idea to check the size of your Flash disk before upgrading the firmware, or before using the disk to store your application and data files. Use the #df -h command to list the size of each memory block and how much free space is available in each block.

192.168.3.127 - PuTTY
root@Moxa:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 8.0M 6.3M 1.7M 78% /
/dev/ram3 1003.0K 9.0K 943.0K 1% /dev
/dev/ram0 499.0K 18.0K 456.0K 4% /var
/dev/mtdblock3 6.0M 504.0K 5.5M 8% /tmp
/dev/mtdblock3 6.0M 504.0K 5.5M 8% /home
/dev/mtdblock3 6.0M 504.0K 5.5M 8% /etc
tmpfs 14.7M 0 14.7M 0% /dev/shm
root@Moxa:~# upramdisk
root@Moxa:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/mtdblock2 8.0M 6.0M 2.0M 75% / 

/dev/ram0 499.0k 16.0k 458.0k 3% /var
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /tmp
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /home
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /etc
tmpfs 30.4M 0 30.4M 0% /dev/shm
/dev/ram1 16.0M 1.0k 15.1M 0% /var/ramdisk
root@Moxa:~# cd /mnt/ramdisk
root@Moxa:/mnt/ramdisk# 

The following instructions give the steps required to save the firmware file to the W315A/325A's RAM disk and how to upgrade the firmware.

1. Type the following commands to enable the RAM disk:

1. Type the following commands to use the W315A/325A's built-in FTP client to transfer the firmware file

(w3x5a-x.x.hfm or w3x5a-x.x.x.hfm) from the PC to the W315A/325A: 

/mnt/ramdisk> ftp <destination PC's IP> 

Login Name: xxxx 

Login Password: xxxx 

ftp> bin 

ftp> get w3x5a-x.x.hfm 

192.168.3.127 - PuTTY

root@Moxa:/mnt/ramdisk# ftp 192.168.3.193
Connected to 192.168.3.193 (192.168.3.193).
220 TYPSoft FTP Server 1.10 ready...
Name (192.168.3.193:root): root
331 Password required for root.
Password:
230 User root logged in.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd newsw
250 CWD command successful. "/C:/ftproot/newsw/" is current directory.
ftp> bin
200 Type set to I.
ftp> ls
200 Port command successful.
150 Opening data connection for directory list.
drw-rw-rw- 1 ftp ftp 0 Nov 30 10:03 .
drw-rw-rw- 1 ftp ftp 0 Nov 30 10:03 .
-rw-rw-rw- 1 ftp ftp 13167772 Nov 29 10:24 w3x5a-1.0.hfm
226 Transfer complete.
ftp> get w3x5a-1.0.hfm
local: w3x5a-1.0.hfm remote: w3x5a-1.0.hfm
200 Port command successful.
150 Opening data connection for w3x5a-1.0.hfm
226 Transfer complete.
13167772 bytes received in 2.17 secs (5925.8 kB/s)
ftp> 

1. Next, use the upgradehfm command to upgrade the kernel and root file system:

upgradehfm w3x5a-x.x.x.hfm

192.168.3.127 - PuTTY

root@Moxa:/mnt/ramdisk# upgradehfm w3x5a-1.0.hfm
Moxa W3x5a upgrade firmware utility version 1.0.
To check source firmware file context.
The source firmware file context is OK.
This step will destroy all your firmware.
Continue ? (Y/N) : Y
Now upgrade the file [kernel].
Format MTD device [/dev/mtd1] . . .
MTD device [/dev/mtd1] erase 128 Kibyte @ 1C0000 - 100% complete.
Wait to write file . . .
Completed 100%
Now upgrade the file [usrdisk].
Format MTD device [/dev/mtd2] . . .
MTD device [/dev/mtd2] erase 128 Kibyte @ 800000 - 100% complete.
Wait to write file . . .
Completed 100%
Upgrade the firmware is OK. 

ATTENTION

The upgradehfm utility will reboot your target after the upgrade is OK.

Loading Factory Defaults

To load the factory default settings, you must press the button for more than 5 seconds. All files in the / home and / etc directories will be destroyed. Note that while pressing the reset button, the Ready LED will blink once every second for the first 5 seconds. The Ready LED will turn off after 5 seconds, and the factory defaults will be loaded.

Enabling and Disabling Daemons

Daemons are programs that run in the background to provide services such as web access, FTP, and email. The following daemons are enabled when the W315A/325A boots up.

inetd Internet Daemons

ftpd FTP Server / Client daemon

sshd Secure Shell Server daemon

httpd Apache WWW Server daemon

Type the command "ps" to list all processes currently running.

192.168.3.127 - PuTTY
root@Moxa:~# cd /etc
root@Moxa:/etc# ps
PID User VSZ STAT COMMAND
1 root 1248 S init [3]
2 root 0 SWN [ksoftirqd/0]
3 root 0 SW< [events/0]
4 root 0 SW< [khelper] 

5 root 0 SW< [kblockd/0]
6 root 0 SW [pdflush]
7 root 0 SW [pdflush]
9 root 0 SW< [aio/0]
8 root 0 SW [kswapd0]
11 root 0 SW< [kmmcd]
10 root 0 SW [mtdblockd]
21 root 0 SWN [jffs2_gcd_mtd3]
53 root 0 S dhcpd eth0
61 root 1284 S /bin/inetd
70 bin 1220 S /bin/portmap
73 root 2096 S /bin/sh --login
80 root 2292 S /bin/egprsagent
142 root 1844 S pppd call chtgprs
194 root 14616 S /usr/bin/httpd -k start -d /etc/apache
197 nobody 14684 S /usr/bin/httpd -k start -d /etc/apache
198 nobody 14684 S /usr/bin/httpd -k start -d /etc/apache
199 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
200 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
201 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
202 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
204 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
205 nobody 14640 S /usr/bin/httpd -k start -d /etc/apache
209 root 1304 S /bin/telnetd
210 root 2084 S -bash
213 root 2300 R ps 

Issue the following commands to list the daemons that run at bootup.

cd /etc/rc.d/rc3.d

1s

192.168.3.127 - PuTTY
root@Moxa:/ect/rc.d/rc3.d# ls
S20snmpd S99rmnologin S99showreadyled
root@Moxa:/etc/rc.d/rc3.d# 

If you would like to add more daemons that run at bootup, run the following command:

cd /etc/rc.d/init.d

Edit a shell script to execute / root/ tcps2-release and save to tcps2 as an example.

cd /etc/rc.d/rc3.d

ln -s /etc/rc.d/init.d/tcps2 S60tcps2

SxxRUNFILE stands for

S: start the run file while linux boots up.

xx: a number between 00-99. Smaller numbers have a higher priority.

RUNFILE: the file name.

192.168.3.127 - PuTTY
root@Moxa:/ect/rc.d/rc3.d# ls
S20snmpd S99rmnologin S99showreadyled
root@Moxa:/ect/rc.d/rc3.d# ln -s /root/tcps2-release S60tcps2
root@Moxa:/ect/rc.d/rc3.d# ls
SS20snmpd S99rmnologin S99showreadyled S60tcps2 

root@Moxa:/etc/rc.d/rc3.d# 

KxxRUNFILE stands for

K: start the run file while linux shuts down or halts.

xx: a number between 00-99. Smaller numbers have a higher priority.

RUNFILE: the file name.

To remove the daemon, remove the run file from the /etc/rc.d/rc3.d directory by using the following command:

rm -f /etc/rc.d/rc3.d/S60tcps2

Starting a Program Automatically at Run-Level

To set a program to run automatically at run-level, edit the file rc.local as follows:

cd /etc/rc.d

vi rc.local

192.168.3.127 - PuTTY
root@Moxa:~# cd /etc/rc.d
root@Moxa:/etc/rc.d# vi rc.local 

Next, use vi to open your application program. We use the example program tcps2-release, and set it to run in the background.

192.168.3.127 - PuTTY
#!/bin/sh
<h1 id="add-you-want-to-run-daemon-hometcps2-release">Add you want to run daemon /home/tcps2-release &~</h1>

The enabled daemons will be available after you reboot the system.

192.168.3.127 - PuTTY
root@Moxa:~# ps
PID Uid VmSize Stat Command
1 root 532 S init [3]
2 root SWN [ksoftirqd/0]
3 root SW< [events/0]
4 root SW< [khelper]
13 root SW< [kblockd/0]
14 root SW [khubd]
24 root SW [pdflush]
25 root SW [pdflush]
27 root SW< [aio/0]
26 root SW [kswapd0]
604 root SW [mtdblockd]
609 root SW [pccardd]
611 root SW [pccardd]
625 root SWN [jffs2_gcd_mtd3]
673 root 500 S /bin/inetd
674 root 1264 S /root/tcps2-release
679 root 3004 S /usr/bin/httpd -k start -d /etc/apache
682 bin 380 S /bin/portmap
685 root 1176 S /bin/sh --login
690 root 464 S /bin/snmpd 

694 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
695 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
696 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
697 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
698 nobody 3012 S /usr/bin/httpd -k start -d /etc/apache
701 root 352 S /bin/reportip
714 root 1176 S -bash
726 root 436 S /bin/telnetd
727 root 1180 S -bash
783 root 628 R ps -ef
root@Moxa:~# 

Adjusting the System Time

Setting the Time Manually

The W315A/325A has two time settings. One is the system time, and the other is the RTC (Real Time Clock) time kept by the W315A/325A's hardware. Use the #date command to query the current system time or set a new system time. Use #hwclock to query the current RTC time or set a new RTC time.

Use the following command to query the system time:

#date

Use the following command to query the RTC time:

#hwclock

Use the following command to set the system time:

date MMDDhhmmYYYY

MM = Month
DD = Date
hhmm = hour and minute
YYYY = Year 

Use the following command to set the RTC time:

hwclock -w

The following figure illustrates how to update the system time and set the RTC time.

192.168.3.127 - PuTTY
root@Moxa:~# date
Fri Jun 23 23:30:31 CST 2000
root@Moxa:~# hwclock
Fri Jun 23 23:30:35 2000 -0.557748 seconds
root@Moxa:~# date 120910002004
Thu Dec 9 10:00:00 CST 2004
root@Moxa:~# hwclock -w
root@Moxa:~# date ; hwclock
Thu Dec 9 10:01:07 CST 2004
Thu Dec 9 10:01:08 2004 -0.933547 seconds
root@Moxa:~# 

NTP Client

The W315A/325A has a built-in NTP (Network Time Protocol) client that is used to initialize a time request to a remote NTP server. Use #ntpdate to update the system time.

#ntpdate time.stdtime.gov.tw
#hwclock -w

Visit http://www.ntp.org for more information about NTP and NTP server addresses.

10.120.53.100 - PuTTY
root@Moxa:~# date ; hwclock
Sat Jan 1 00:00:36 CST 2000
Sat Jan 1 00:00:37 2000 -0.772941 seconds
root@Moxa:~# ntpdate time.stdton.gov.tw
9 Dec 10:58:53 ntpdate[207]: step time server 220.130.158.52 offset 155905087.9
84256 sec
root@Moxa:~# hwclock -w
root@Moxa:~# date ; hwclock
Thu Dec 9 10:59:11 CST 2004
Thu Dec 9 10:59:12 2004 -0.844076 seconds
root@Moxa:~# 

NOTE

Before using the NTP client utility, check your IP and DNS settings to make sure that an Internet connection is available. Refer to Chapter 2 for instructions on how to configure the Ethernet interface, and see Chapter 4 for DNS setting information.

Updating the Time Automatically

In this subsection, we show how to use a shell script to update the time automatically.

Example shell script to update the system time periodically

!/bin/sh

ntpdate time.nist.gov # You can use the time server's ip address or domain
<h1 id="name-directly-if-you-use-domain-name-you-must">name directly. If you use domain name, you must</h1>
<h1 id="enable-the-domain-client-on-the-system-by-updating">enable the domain client on the system by updating</h1>
<h1 id="etcresolvconf-file">/etc/resolv.conf file.</h1>

hwclock --systohc

sleep 100 # Updates every 100 seconds. The sleeping time is 100 seconds. Change # 100 to a larger number to update RTC less often. 

Save the shell script using any file name. E.g., fixtime

How to run the shell script automatically when the kernel boots up

Copy the example shell script fixtime to directory /etc/init.d, and then use

chmod 755 fixtime to change the shell script mode. Next, use vi editor to edit the file /etc/inittab. Add the following line to the bottom of the file:

Use the command #init q to re-init the kernel.

Cron—Daemon for Executing Scheduled Commands

Cron is a scheduling service in Linux. Cron wakes up every minute, and checks the configuration file named crontab to see if any scheduled commands should be run at the current moment.

Crontab is located in the /etc/cron.d directory. Modify the file /etc/cron.d/crontab to set up your scheduled applications. Crontab has the following format:

mm	h	dom	mon	dow	user	command
min	hour	date	month	week	user	command
0-59	0-23	1-31	1-12	0-6 (0 is Sunday)

The following example demonstrates how to use Cron.

How to use cron to update the system time and RTC time every day at 8:00.

STEP 1: Write a shell script named fixtime.sh and save it to / home/.

!/bin/sh

ntpdate time.nist.gov

hwclock --systohc

exit 0

STEP 2: Change mode of fixtime.sh

chmod 755 fixtime.sh

STEP 3: Modify /etc/cron.d/crontab file to run fixtime.sh at 8:00 every day.

Add the following line to the end of crontab:

* 8 * * * root /home/fixtime.sh

STEP 4: Enable the cron daemon manually.

/etc/init.d/cron start

STEP 5: Enable cron when the system boots up.

By default, cron service is disabled on boot. To enable cron service, refer to the section "Enabling and Disabling Daemons" in this chapter

In this chapter, we explain how to configure the W315A/325A's various communications functions.

The following topics are covered in this chapter:

Telnet/ FTP
DNS
□ Web Service—Apache
☐ Installing PHP for Apache Web Server
□ IPTABLES

➢ Observe and Erase Chain Rules
➢ Define Policy for Chain Rules
Append or Delete Rules

NAT

NAT Example
Enabling NAT at Bootup

□ Dial-up Service—PPP

How to Check the Connection
Setting up a Machine for Incoming PPP Connections

□ PPPoE

□ GPRS Connection

➢ Configuring the options for pppd
➢ Configuring the AT commands
Example: Selecting the radio band

□ NFS (Network File System)

Setting up the W315A/325A as an NFS Client

Mail
SNMP

Telnet/ FTP

In addition to supporting Telnet client and FTP client/server, the W315A/325A also supports SSH and sftp client/server. To enable or disable the Telnet/ftp server, you first need to edit the file /etc/inetd.conf.

Enabling the Telnet/ ftp server

The following example shows the default content of the file /etc/inetd.conf. The default is to enable the Telnet/ftp server:

discard dgram udp wait root /bin/discard discard stream tcp nowait root /bin/discard ftp stream tcp nowait root /bin/ftpd -l

Disabling the ftp server

Disable the daemon by typing ‘#’ in front of the first character of the row to comment out the line.

DNS

The W315A/325A supports DNS client (but not DNS server). To set up DNS client, you need to edit three configuration files: /etc/hosts, /etc/resolv.conf, and /etc/nsswitch.conf.

/etc/hosts is the first file that the Linux system reads to resolve the host name and IP address.

/etc/resolv.conf is the most important file that you need to edit when using DNS for the other programs. For example, before you use # ntpdate time.nist.goc to update the system time, you will need to add the DNS server address to the file. Ask your network administrator which DNS server address you should use. The DNS server's IP address is specified with the "nameserver" command. For example, add the following line to /etc/resolv.conf if the DNS server's IP address is 168.95.1.1:

nameserver 168.95.1.1

10.120.53.100 - PuTTY
root@Moxa:/etc# cat resolv.conf
#
<h1 id="resolvconf-this-file-is-the-resolver-configuration-file">resolv.conf This file is the resolver configuration file</h1>
<h1 id="see-resolver5">See resolver(5).</h1>
#
#nameserver 192.168.1.16
nameserver 168.95.1.1
nameserver 140.115.1.31
nameserver 140.115.236.10
root@Moxa:/etc# 

/etc/nsswitch.conf defines the sequence to resolve the IP address by using /etc/hosts or /etc/resolv.conf.

Web Service—Apache

The Apache web server's main configuration file is /etc/apache/conf/httpd.conf, with the default homepage located at /home/httpd/htdocs/index.html. Save your own homepage to the following directory:

/home/httpd/htdocs/

Save your CGI page to the following directory:

/home/httpd/cgi-bin/

Before you modify the homepage, use a browser (such as Microsoft Internet Explore or Mozilla Firefox) from your PC to test if the Apache Web Server is working. Type the LAN IP address in the browser's address box to open the homepage. E.g., type http://192.168.13.23 in the address box.

To open the default CGI page, type http://192.168.13.23/cgi-bin/test-cgi in your browser's address box.

NOTE

The CGI function is enabled by default. If you want to disable the function, modify the file /etc/apache/conf/httpd.conf. When you develop your own CGI application, make sure your CGI file is executable.

192.168.3.127 - PuTTY
root@Moxa:/home/httpd/cgi-bin# ls -al
drwxr-xr-x 2 root root 0 Aug 24 1999
drwxr-xr-x 5 root root 0 Nov 5 16:16
-rwxr-xr-x 1 root root 757 Aug 24 1999 test-cgi
root@Moxa:/home/httpd/cgi-bin# 

Installing PHP for Apache Web Server

The W315A/325A embedded computer supports the PHP option. However, since the PHP file is 3 MB, it is not installed by default. To install it yourself, first make sure there is enough free space (at least 3 MB) on your embedded flash ROM).

Step 1: Check that you have enough free space The following figure illustrates how to check that the /dev/ mtdblock3 has more than 3 MB of free space.

192.168.3.127 - PuTTY
root@Moxa:/bin# df -h
Filesystem Size Used Available Use% Mounted on
/dev/mtdblock2 8.0M 6.0M 2.0M 75% /
/dev/ram0 499.0k 17.0k 457.0k 4% /var
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /tmp
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /home
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /etc
tmpfs 30.4M 0 30.4M 0% /dev/shm
root@Moxa:/bin# 

Step 2: Type upramdisk to get the free space ram disk to save the package.

192.168.3.127 - PuTTY
root@Moxa:/bin# upramdisk
root@Moxa:/bin# df -h
Filesystem Size Used Available Use% Mounted on
/dev/mtdblock2 8.0M 6.0M 2.0M 75% /
/dev/ram0 499.0k 18.0k 456.0k 4% /var
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /tmp
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /home
/dev/mtdblock3 6.0M 488.0k 5.5M 8% /etc
tmpfs 14.7M 0 14.7M 0% /dev/shm
/dev/ram1 16.0M 1.0k 15.1M 0% /var/ramdisk
root@Moxa:/bin# 

Step 3: Download the PHP package from the CD-ROM. You can find the package in CD-ROM/target/php/php.tgz.

192.168.3.127 - PuTTY
root@Moxa:/bin# cd /mnt/ramdisk
root@Moxa:/mnt/ramdisk# ftp 192.168.27.130
Connected to 192.168.27.130.
220 (vsFTPd 2.0.1)
Name (192.168.27.130:root): root 

331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd /tmp
250 Directory successfully changed.
ftp> bin
200 Switching to Binary mode.
ftp> get php.tgz
local: php.tgz remote: php.tgz
200 PORT command successful. Consider using PASV.
150 Opening BINARY mode data connection for php.tgz (1789032 bytes).
226 File send OK.
1789032 bytes received in 0.66 secs (2.6e+03 Kbytes/sec)
ftp> 

Step 4: Untar the package. To do this, type the command tar xvzf php.tgz.

192.168.3.127 - PuTTY

root@Moxa:/mnt/ramdisk# tar xvzf php.tgz
apache-sdlinux/

apache-sdlinux/apachectl
apache-sdlinux/libpng12.so.0
apache-sdlinux/libmysqlclient.so.16
apache-sdlinux/libgd.so.2
apache-sdlinux/apache-2/
apache-sdlinux/apache-2/logs/
apache-sdlinux/apache-2/logs/error_log
apache-sdlinux/apache-2/logs/ssl_request_log
apache-sdlinux/apache-2/logs/access_log
apache-sdlinux/apache-2/php/
apache-sdlinux/apache-2/php/php.ini
apache-sdlinux/apache-2/conf/
apache-sdlinux/apache-2/conf/magic
apache-sdlinux/apache-2/conf/extra/
apache-sdlinux/apache-2/conf/extra/httpd-userdir.conf
apache-sdlinux/apache-2/conf/extra/httpd-multilang-errordoc.conf
apache-sdlinux/apache-2/conf/extra/httpd-dav.conf
apache-sdlinux/apache-2/conf/extra/httpd-manual.conf
apache-sdlinux/apache-2/conf/extra/httpd-autoindex.conf
apache-sdlinux/apache-2/conf/extra/httpd-vhosts.conf
apache-sdlinux/apache-2/conf/extra/httpd-ssl.conf
apache-sdlinux/apache-2/conf/extra/httpd-info.conf
apache-sdlinux/apache-2/conf/extra/httpd-default.conf
apache-sdlinux/apache-2/conf/extra/httpd-mpm.conf
apache-sdlinux/apache-2/conf/extra/httpd-languages.conf
apache-sdlinux/apache-1/conf/httpd.conf
apache-sdlinux/apache-1/conf/httpd.conf.bak
apache-sdlinux/apache-1/conf/mime.types
apache-sdlinux/apache-1/conf/original/
apache-sdlinux/apache-1/conf/original/extra/
apache-sdlinux/apache-1/conf/original/extra/httpd-userdir.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-multilang-errordoc.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-dav.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-manual.conf 

apache-sdlinux/apache-1/conf/original/extra/httpd-autoindex.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-vhosts.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-ssl.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-info.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-default.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-mpm.conf
apache-sdlinux/apache-1/conf/original/extra/httpd-languages.conf
apache-sdlinux/apache-1/conf/original/httpd.conf
apache-sdlinux/apache-1/envvars
apache-sdlinux/install.sh
apache-sdlinux/libxml2.so.2
apache-sdlinux/phpinfo.php
apache-sdlinux/libjpeg.so.62
apache-sdlinux/ssl_keygen.sh
root@Moxa:/mnt/ramdisk# 

Step 5: Run install.sh and select to install php.

192.168.3.127 - PuTTY

root@Moxa:/mnt/ramdisk/apache-sdlinux# ./install.sh
Press the number:
1. Install Apache.
2. Install Apache + PHP.
3. Install Apache + SSL + PHP.
4. Uninstall Apache.
5. Exit.
2
Installing, Please wait......
Install successful...

Starting web server: apache
root@Moxa:/mnt/ramdisk/apache-sdlinux# 

Step 6: Test it. Use the browser to access http://192.168.3.127/phpinfo.php.

If you want to uninstall PHP, follow steps 2 to 5 but select the uninstall option.

IPTABLES

IPTABLES is an administrative tool for setting up, maintaining, and inspecting the Linux kernel's IP packet filter rule tables. Several different tables are defined, with each table containing built-in chains and user-defined chains.

Each chain is a list of rules that apply to a certain type of packet. Each rule specifies what to do with a matching packet. A rule (such as a jump to a user-defined chain in the same table) is called a "target."

The W315A/325A supports 3 types of IPTABLES table: Filter tables, NAT tables, and Mangle tables:

A. Filter Table—includes three chains:

INPUT chain

OUTPUT chain

FORWARD chain

B. NAT Table — includes three chains:

PREROUTING chain—transfers the destination IP address (DNAT)

POSTROUTING chain—works after the routing process and before the Ethernet device process to transfer the source IP address (SNAT)

OUTPUT chain—produces local packets

Use the following optional parameters to configure the NAT table.

Source NAT (SNAT) changes the first source packet IP address

Destination NAT (DNAT)—changes the first destination packet IP address

MASQUERADE a special form for SNAT. If one host can connect to Internet, then other computers that connect to this host can connect to the Internet when the computer does not have an actual IP address.

REDIRECT—a special form of DNAT that re-sends packets to a local host independent of the destination IP address.

C. Mangle Table—includes two chains

PREROUTING chain—pre-processes packets before the routing process.

OUTPUT chain processes packets after the routing process.

It has three extensions—TTL, MARK, TOS.

The following figure shows the IPTABLES hierarchy.

graph TD
    A["Incoming Packets"] --> B["Mangle Table PREROUTING Chain"]
    B --> C["NAT Table PREROUTING Chain"]
    C --> D["Local Host Packets"]
    C --> E["Other Host Packets"]
    D --> F["Mangle Table INPUT Chain"]
    F --> G["Filter Table INPUT Chain"]
    G --> H["Local Process"]
    H --> I["Mangle Table OUTPUT Chain"]
    I --> J["NAT Table OUTPUT Chain"]
    J --> K["Filter Table OUTPUT Chain"]
    K --> L["NAT Table POSTROUTING Chain"]
    L --> M["Outgoing Packets"]
    E --> N["Mangle Table FORWARD Chain"]
    N --> O["Filter Table FORWARD Chain"]
    O --> P["Mangle Table POSTROUTING Chain"]

The W315A/325A supports the following sub-modules. Be sure to use the module that matches your application.

ip_conntrack	ipt_MARK	ipt_ah	ipt_state
ip_conntrack_ftp	ipt_MASQUERADE	ipt_esp	ipt_tcpmss
ipt_conntrack_irc	ipt_MI RROT	ipt_length	ipt_tos
ip_nat_ftp	ipt_REDIRECT	ipt_limit	ipt_ttl
ip_nat_irc	ipt_REJECT	ipt_mac	ipt_unclean
ip_nat_snmp_basic	ipt_TCPMSS	ipt_mark
ip_queue	ipt_TOS	ipt_multiport
ipt_LOG	ipt_ULOG	ipt_owner

NOTE

The W315A/325A does NOT support IPV6 and ipchains.

The basic syntax to enable and load an IPTABLES module is as follows:

1smod

modprobe ip_tables

modprobe iptable_filter

Use lsmod to check if the ip_tables module has already been loaded in the W315A/325A. Use modprobe to insert and enable the module.

Use the following command to load the modules (iptable_filter, iptable_mangle, iptable_nat):

modprobe iptable_filter

NOTE

IPTABLES plays the role of packet filtering or NAT. Take care when setting up the IPTABLES rules. If the rules are not correct, remote hosts that connect via a LAN or PPP may be denied access. We recommend using the Serial Console to set up the IPTABLES.

Click on the following links for more information about iptables.

http://www.linuxguruz.com/iptables/

http://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO.html

Since the IPTABLES command is very complex, to illustrate the IPTABLES syntax we have divided our discussion of the various rules into three categories: Observe and erase chain rules, Define policy rules, and Append or delete rules.

Observe and Erase Chain Rules

Usage:

# iptables [-t tables] [-L] [-n]

-t tables: Table to manipulate (default: 'filter'); example: nat or filter.
-L [chain]: List List all rules in selected chains. If no chain is selected, all chains are listed.
-n: Numeric output of addresses and ports.

# iptables [-t tables] [-FXZ]

-F: Flush the selected chain (all the chains in the table if none is listed).
-X: Delete the specified user-defined chain.
-Z: Set the packet and byte counters in all chains to zero.

Examples:

# iptables -L -n

In this example, since we do not use the -t parameter, the system uses the default 'filter' table. Three chains are included: INPUT, OUTPUT, and FORWARD. INPUT chains are accepted automatically, and all connections are accepted without being filtered.

#iptables -F
#iptables -X
#iptables -Z 

Define Policy for Chain Rules

Usage:

# iptables [-t tables] [-P] [INPUT, OUTPUT, FORWARD, PREROUTING, OUTPUT, POSTROUTING] [ACCEPT, DROP]

-P: Set the policy for the chain to the given target.

INPUT: For packets coming into the W315A/325A.

OUTPUT: For locally-generated packets.

FORWARD: For packets routed out through the W315A/325A.

PREROUTING: To alter packets as soon as they come in.

POSTROUTING: To alter packets as they are about to be sent out.

Examples:

#iptables -P INPUT DROP
#iptables -P OUTPUT ACCEPT
#iptables -P FORWARD ACCEPT
#iptables -t nat -P PREROUTING ACCEPT
#iptables -t nat -P OUTPUT ACCEPT
#iptables -t nat -P POSTROUTING ACCEPT 

In the above examples, the policy accepts outgoing packets and denies incoming packets.

Append or Delete Rules

Usage:

<h1 id="iptables-t-table-ai-input-output-forward-io-interface-p-tcp-udp-icmp-all-s-ipnetwork-sport-ports-d-ipnetwork-dport-ports-j-accept-drop">iptables [-t table] [-AI] [INPUT, OUTPUT, FORWARD] [-io interface] [-p tcp, udp, icmp, all] [-s IP/network] [--sport ports] [-d IP/network] [--dport ports] -j [ACCEPT. DROP]</h1>

-A: Append one or more rules to the end of the selected chain.
-l: Insert one or more rules in the selected chain as the given rule number.
-i: Name of an interface via which a packet is going to be received.
-o: Name of an interface via which a packet is going to be sent.
-p: The protocol of the rule or of the packet to check.
-s: Source address (network name, host name, network IP address, or plain IP address).
--sport: Source port number.
-d: Destination address.
--dport: Destination port number.
-j: Jump target. Specifies the target of the rules; i.e., how to handle matched packets. For example, ACCEPT the packet, DROP the packet, or LOG the packet. 

Examples:

Example 1: Accept all packets from lo interface.
<h1 id="iptables-a-input-i-lo-j-accept">iptables -A INPUT -i lo -j ACCEPT</h1>

Example 2: Accept TCP packets from 192.168.0.1.
<h1 id="iptables-a-input-i-eth0-p-tcp-s-19216801-j-accept">iptables -A INPUT -i eth0 -p tcp -s 192.168.0.1 -j ACCEPT</h1>

Example 3: Accept TCP packets from Class C network 192.168.1.0/24.
<h1 id="iptables-a-input-i-eth0-p-tcp-s-1921681024-j-accept">iptables -A INPUT -i eth0 -p tcp -s 192.168.1.0/24 -j ACCEPT</h1>

Example 4: Drop TCP packets from 192.168.1.25.
<h1 id="iptables-a-input-i-eth0-p-tcp-s-192168125-j-drop">iptables -A INPUT -i eth0 -p tcp -s 192.168.1.25 -j DROP</h1>

Example 5: Drop TCP packets addressed for port 21.
<h1 id="iptables-a-input-i-eth0-p-tcp-dport-21-j-drop">iptables -A INPUT -i eth0 -p tcp --dport 21 -j DROP</h1>

Example 6: Accept TCP packets from 192.168.0.24 to W315A/325A's port 137, 138, 139
<h1 id="iptables-a-input-i-eth0-p-tcp-s-192168024-dport-137139-j-accept">iptables -A INPUT -i eth0 -p tcp -s 192.168.0.24 --dport 137:139 -j ACCEPT</h1>

Example 7: Drop all packets from MAC address 01:02:03:04:05:06.
<h1 id="iptables-a-input-i-eth0-p-all-m-mac-mac-source-010203040506-j-drop">iptables -A INPUT -i eth0 -p all -m mac --mac-source 01:02:03:04:05:06 -j DROP</h1>

NOTE In Example 7, remember to issue the command #modprobe ipt_mac first to load module ipt_mac.

NAT

NAT (Network Address Translation) protocol translates IP addresses used on one network to different IP addresses used on another network. One network is designated the inside network and the other is the outside network. Typically, the W315A/325A connects several devices on a network and maps local inside network

addresses to one or more global outside IP addresses, and un-maps the global IP addresses on incoming packets back into local IP addresses.

NOTE

Click on the following link for more information about iptables and NAT: http://www.netfilter.org/documentation/HOWTO/NAT-HOWTO.html

NAT Example

The IP address of the LAN is changed to 192.168.3.127 (you will need to load the module ipt_MASQUERADE):

graph TD
    A["GPRS Network"] --> B["Embedded Computer"]
    B --> C["PC (Linux or Windows)"]
    A -->|GPRS: 211.120.21.171| D
    B -->|LAN: 192.168.3.127/24| E
    C -->|IP/Network: 192.168.3.100/24\nGateway: 192.168.3.127| F

1. echo 1 > /proc/sys/net/ipv4/ip_forward

2. modprobe ip_tables

3. modprobe iptable_filter

4. modprobe ip_conntrack

5. modprobe iptable_nat

6. modprobe ipt_MASQUERADE

7. iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source 192.168.3.127

8. iptables -t nat -A POSTROUTING -o eth0 -s 192.168.3.0/24 -j MASQUERADE

Enabling NAT at Bootup

In most real world situations, you will want to use a simple shell script to enable NAT when the W315A/325A boots up. The following script is an example.

#!/bin/bash
<h1 id="if-you-put-this-shell-script-in-the-homenatsh">If you put this shell script in the /home/nat.sh</h1>
<h1 id="remember-to-chmod-744-homenatsh">Remember to chmod 744 /home/nat.sh</h1>
<h1 id="edit-the-rclocal-file-to-make-this-shell-startup-automatically">Edit the rc.local file to make this shell startup automatically.</h1>
<h1 id="vi-etcrcdrclocal">vi /etc/rc.d/rc.local</h1>
<h1 id="add-a-line-in-the-end-of-rclocal-homenatsh">Add a line in the end of rc.local /home/nat.sh</h1>
EXIF='eth0' #This is an external interface for setting up a valid IP address.
EXNET='192.168.4.0/24' #This is an internal network address.
<h1 id="step-1-insert-modules">Step 1. Insert modules.</h1>
<h1 id="here-2-devnull-means-the-standard-error-messages-will-be-dump-to-null-device">Here 2> /dev/null means the standard error messages will be dump to null device.</h1>
modprobe ip_tables 2> /dev/null
modprobe ip_conntrack 2> /dev/null
modprobe ip_conntrack_ftp 2> /dev/null
modprobe ip_conntrack_irc 2> /dev/null
modprobe iptable_nat 2> /dev/null
modprobe ip_nat_ftp 2> /dev/null
modprobe ip_nat_irc 2> /dev/null 

<h1 id="step-2-define-variables-enable-routing-and-erase-default-rules">Step 2. Define variables, enable routing and erase default rules.</h1>
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
export PATH

echo "1" > /proc/sys/net/ipv4/ip_forward
/bin/iptables -F
/bin/iptables -X
/bin/iptables -Z
/bin/iptables -F -t nat
/bin/iptables -X -t nat
/bin/iptables -Z -t nat
/bin/iptables -P INPUT ACCEPT
/bin/iptables -P OUTPUT ACCEPT
/bin/iptables -P FORWARD ACCEPT
/bin/iptables -t nat -P PREROUTING ACCEPT
/bin/iptables -t nat -P POSTROUTING ACCEPT
/bin/iptables -t nat -P OUTPUT ACCEPT
<h1 id="step-3-enable-ip-masquerade">Step 3. Enable IP masquerade.</h1>

Dial-up Service—PPP

PPP (Point to Point Protocol) is used to run IP (Internet Protocol) and other network protocols over a serial link. PPP can be used for direct serial connections (using a null-modem cable) over a Telnet link, and links established using a modem over a telephone line.

Modem/PPP access is almost identical to connecting directly to a network through the W315A/325A's Ethernet port. Since PPP is a peer-to-peer system, the W315A/325A can also use PPP to link two networks (or a local network to the Internet) to create a Wide Area Network (WAN).

NOTE

Click on the following links for more information about ppp: http://tldp.org/HOWTO/PPP-HOWTO/index.html http://axion.physics.ubc.ca/ppp-linux.html 

The pppd daemon is used to connect to a PPP server from a Linux system. For detailed information about pppd see the man page.

Example 1: Connecting to a PPP server over a simple dial-up connection

The following command is used to connect to a PPP server by modem. Use this command for old ppp servers that prompt for a login name (replace username with the correct name) and password (replace password with the correct password). Note that debug and defaultroute 192.1.1.17 are optional.

pppd connect 'chat -v " " ATDT5551212 CONNECT" " ogin: username word: password'/dev/ttyM0 115200 debug crtscts modem defaultroute

If the PPP server does not prompt for the username and password, the command should be entered as follows. Replace username with the correct username and replace password with the correct password.

pppd connect 'chat -v " " ATDT5551212 CONNECT" " ' user username password password /dev/ttyM0 115200 crtscts modem

The pppd options are described below:

connect 'chat etc...'

This option gives the command to contact the PPP server. The 'chat' program is used to dial a remote computer. The entire command is enclosed in single quotes because pppd expects a one-word argument for the 'connect' option. The options for 'chat' are given below:

-v

verbose mode; log what we do to syslog

“ ”

Double quotes—don't wait for a prompt, but instead do ... (note that you must include a space after the second quotation mark)

ATDT5551212

Dial the modem, and then ...

CONNECT

Wait for an answer.

“ ”

Send a return (null text followed by the usual return)

ogin: username word: password

Log in with username and password.

Refer to the chat man page, chat.8, for more information about the chat utility.

/dev/

Specify the callout serial port.

115200

The baudrate.

debug

Log status in syslog.

crtscts

Use hardware flow control between computer and modem (at 115200 this is a must).

modem

Indicates that this is a modem device; pppd will hang up the phone before and after making the call.

defaultroute

Once the PPP link is established, make it the default route; if you have a PPP link to the Internet, this is probably what you want.

192.1.1.17

This is a degenerate case of a general option of the form x.x.x.x:y.y.y.y. Here x.x.x.x is the local IP address and y.y.y.y is the IP address of the remote end of the PPP connection. If this option is not specified, or if just one side is specified, then x.x.x.x defaults to the IP address associated with the local machine's hostname (located in /etc/hosts), and y.y.y.y is determined by the remote machine.

Example 2: Connecting to a PPP server over a hard-wired link

If a username and password are not required, use the following command (note that noipdefault is optional):

pppd connect 'chat -v" " " " ' noipdefault /dev/ttyM0 19200 crtscts

If a username and password is required, use the following command (note that noipdefault is optional, and root is both the username and password):

pppd connect 'chat -v" " " " ' user root password root noipdefault /dev/ttyM0 19200 crtscts

How to Check the Connection

Once you've set up a PPP connection, there are some steps you can take to test the connection. First, type:

#ifconfig

You should be able to see all the network interfaces that are UP. ppp0 should be one of them, and you should recognize the first IP address as your own, and the "P-t-P address" (or point-to-point address) the address of your server. Here's what it looks like on one machine:

lo Link encap Local Loopback
	inet addr 127.0.0.1 Bcast 127.255.255.255 Mask 255.0.0.0
	UP LOOPBACK RUNNING MTU 2000 Metric 1
RX packets 0 errors 0 dropped 0 overrun 0
ppp0	Link encap Point-to-Point Protocol
	inet addr 192.76.32.3 P-t-P 129.67.1.165 Mask 255.255.255.0
UP POINTOPOINT RUNNING MTU 1500 Metric 1
RX packets 33 errors 0 dropped 0 overrun 0
TX packets 42 errors 0 dropped 0 overrun 0

Now, type:

ping z.z.z.z

where z.z.z.z is the address of your name server. The response could look like:

# ping 129.67.1.165
PING 129.67.1.165 (129.67.1.165): 56 data bytes
64 bytes from 129.67.1.165: icmp_seq=0 ttl=225 time=268 ms
64 bytes from 129.67.1.165: icmp_seq=1 ttl=225 time=247 ms
64 bytes from 129.67.1.165: icmp_seq=2 ttl=225 time=266 ms
^ C
--- 129.67.1.165 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 247/260/268 ms
waddington:~$

Try typing:

netstat -nr

This should show three routes, such as the following:

Kernel routing table
Destination	Gateway	Genmask	Flags	Metric	Ref	Use
iface
129.67.1.165	0.0.0.0	255.255.255.255	UH	0	0	6
ppp0
127.0.0.0	0.0.0.0	255.0.0.0	U	0	0	0 lo
0.0.0.0	129.67.1.165	0.0.0.0	UG	0	0	6298
ppp0

If your output looks similar but doesn't have the destination 0.0.0.0 line (which refers to the default route used for connections), you may have run pppd without the 'defaultroute' option. At this point you can try using Telnet, ftp, or finger, bearing in mind that you'll have to use numeric IP addresses unless you've set up /etc/resolv.conf correctly.

Setting up a Machine for Incoming PPP Connections

This first example applies to using a modem requiring authorization with a username and password.

pppd/dev/ttyM0 115200 crtscts modem 192.168.16.1:192.168.16.2 login auth

You should also add the following line to the file / etc/ ppp/ pap-secrets:

* * " " *

The first star (*) lets everyone login. The second star (*) lets every host connect. The pair of double quotation marks (“”) indicates to use the file / etc/passwd to check the password. The last star (*) lets any IP connect.

The following example does not check the username and password:

pppd/dev/ttyM0 115200 crtscts modem 192.168.16.1:192.168.16.2

PPPoE

1. Connect the W315A/325A's LAN port to an ADSL modem with a cross-over cable, HUB, or switch.
2. Log on to the W315A/325A as the root user.
3. Edit the file /etc/ppp/chap-secrets and add the following text:

"[e-mail]" * "password" *

“[e-mail]” is the username obtained from the ISP to log in to the ISP account. “password” is the corresponding password for the account.

1. Edit the file / etc/ ppp/ pap-secrets and add the following text:

"[e-mail]" * "password" *

“[e-mail]” is the username obtained from the ISP to log in to the ISP account. “password” is the corresponding password for the account.

1. Edit the file /etc/ppp/options and add the following line:

plugin pppoe