Appendix B. Using the System Console to Analyze the AP and Network
By using a direct serial connection from a PC to a console port on the access point (AP) or by using Telnet on the IP address of the access point, you can get a low-level view into Devicescape Enterprise-Managed AP startup messages and system logs through the system console.
You can use Linux commands to see network configuration information like IP addresses and bridge configurations. Also, at the system console you can enter LSQL commands to retrieve information directly from the AP system configuration file (apconfid.xml), and other key files.
This information can be useful initially for debugging your network setup, to get IP addresses, and view client association / disassociation events. System console access is also useful for performance testing.
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Note
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The system console interface described here is not intended to serve as a formal command line interface (CLI) for AP administration, and we do not include this information in our end-user documentation. This information is intended for use by evaluators and manufacturers only.
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This following topics provide a more in-depth picture of network setup of Ethernet (wired) / Radio (wireless) interfaces, and explain how to access and use the system console to get details on those interfaces.
Connecting to the AP and Accessing the System Console
You can use either of these methods to access the system console for the access point:
Use a direct serial port connection to the access point
If your Evaluation unit has a serial port (not all do), you can create a direct physical connection into the access point by connecting a cable from a laptop or desktop PC to a serial port on the access point. Then, using terminal emulation software, you can access the AP system console through the emulated UNIX-based command window on your PC.
Prerequisites
- A serial cable
Connect one end of the serial cable to the PC and the other end of the cable to the serial port on the access point.
We suggest using "TeraTerm Pro" instead of the Windows XP built in "HyperTerminal" to capture console output as it provides more reliable scrolling through the screen buffer without messing up the screen information.
Terminal Emulation Configuration
- Set up a new Serial Port connection to "COM1".
For example, on Tera Term Pro choose File > New Connection if the dialog is not displayed automatically.
- Configure the Serial Port connection.
For example, to access the Serial Port settings on TeraTerm Pro choose Setup > Serial Port from the Tera Term menu.
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Serial Port Options
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Recommended Settings
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Port
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COM1
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Baud rate
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115200
Note: The Baud rate may vary depending on the AP platform. A Baud rate of 115200 is appropriate for most platforms, including the Intel® ADI Coyote board and Atheros wireless-system-on-a-chip (WiSOC). If the Baud rate setting is incorrect, the system console messages will be unreadable.
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Data
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8 bits
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Parity
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none
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Stop bits
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1
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Flow control
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none
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Notes
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- If you are connected to the serial port before changing the Baud rate to the correct setting, you may see some garbled messages. If that happens, go to "Control" menu and click on "Reset terminal". Change Baud rate.
- To increase Scroll buffer, go to "Setup" menu and click on "Window" and change the "Scroll buffer" value.
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- Save Setup.
When you have configured the Serial Port settings as desired, choose Setup > Save Setup to save the configuration to a an initialization file (TERRATERM.INI) so that these settings will be used the next time you bring up the Tera Term window. (If you do not save setup, you will have to re-set the Serial Port configuration every time you start Tera Term.)
Set up Network Connections and Start the AP
The following setup assumes a DHCP server. f there is no DHCP server on the network, the AP retains its default static IP address (192.168.1.10. I) at first-time startup. (For more about IP addressing, see "Determine IP Address of AP and Access Administration Web Pages" on page 9.)
- Connect the primary Ethernet port (eth0) on the access point (AP) to the company gateway.
- Connect the secondary Ethernet port on the AP (eth1) the internet gateway to enable a physically separate Guest Network. (Skip this step if you only have one gateway or are not interested in the Guest network access feature.)
- Connect an Ethernet port on your PC (the one used to monitor the AP) to the company gateway.
- Power-up the access point.
On the serial console, you will see startup messages similar to the following as the AP boots up:
When the initialization sequence is complete, the system console displays messages similar to the following:
apconfd: Initialization complete.
apconfd: dhcpc: Interface br0 obtained lease on 10.10.100.123.
- When you see that the access point has obtained an IP address on
br0, press the "Enter" or "Return" key on your PC keyboard to get a command prompt in the Tera Term window.
- You will be prompted for an Administrator user name and password for the access point.
Instant802-AP login:
Password:
Enter the default Administrator username and password for the Devicescape Enterprise-Managed AP (admin, admin), and press "Enter" after each.
When the user name and password is accepted, the screen displays the BusyBox command prompt.
BusyBox v1.00-pre7 (2004.05.07-20:11+0000) Built-in shell (msh)
Enter 'help' for a list of built-in commands.
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You are now ready to enter LSQL or Linux commands to view low-level, system information about the access point. See "Using Linux Commands to Get Network Information on the AP" on page 52
Telnet to the IP address of the Access Point
If you know already have your network deployed and know the IP address of your access point, you can use "Telnet" terminal emulation to view the system console over the network.
Using Telnet tends to be more convenient because it gives you remote access the AP system console. The only disadvantage of using Telnet (versus the direct serial port connection) is that with Telnet you cannot access the system console until the AP is fully initialized. (LEDs on the AP should indicate when the AP has booted. Specifics will vary depending on the AP manufacturer.) Therefore, you cannot view AP startup messages or interrupt the AP boot sequence using Telnet as you can do with a direct serial port connection. However, once the AP is operational you can use a Telnet connection to view the AP system console and enter commands in exactly the same way as you would with a serial port connection.
- Bring up a command window on your PC.
(For example, from the system tray on the desktop choose choose Start > Run to bring up the Run dialog, and type cmd in the Open field, and click OK.)
- At the command prompt, type the following:
telnet IPAddressOfAccessPoint
where IPAddressOfAccessPoint is the address of the access point you want to monitor.
- You will be prompted for an Administrator user name and password for the access point.
Instant802-AP login:
Password:
Enter the default Administrator username and password for the Devicescape Enterprise-Managed AP (admin, admin), and press "Enter" after each. When the user name and password is accepted, the screen displays the BusyBox command prompt.
BusyBox v1.00-pre7 (2004.05.07-20:11+0000) Built-in shell (msh)
Enter 'help' for a list of built-in commands.
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You are now ready to enter LSQL or Linux commands to view low-level, system information about the access point. See Using Linux Commands to Get Network Information on the AP.
Using Linux Commands to Get Network Information on the AP
The Devicescape Enterprise-Managed AP system console provides a low-level view into system messages and logs. You can use the system console for testing and debugging. For example, system messages can give you insight into situations where an associated client is not getting an IP address or gets disconnected, or when the Administration UI is not accessible.
You can use standard Linux commands at the Busy Box command prompt to get a list of processes running on the access point, and to see network configuration information like IP addresses and bridge configurations.
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Command
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Description
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ps
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Shows a list of running processes for the access point. (See example picture above at the beginning of this section.) Following are descriptions of a few key processes and some others that may be of interest. (This is by no means a complete list.)
- /sbin/apconfd - Access point configuration daemon (apconfd). Provides the basic definitions of the system, such as the IP Address. It maintains the running configuration for the access point and handles requests from the Web Administration pages.
apconfd configures, launches, and monitors all other functions on the access point. (This must be running to enable access to the Administration Web UI.)
- /sbin/getty -L 115200 ttyS0 - Your serial port cable connection from PC to AP, (This will not show if you Telnet remotely into the AP.)
- [ixp425 eth0] - Ethernet port of the AP
- /usr/sbin/mini_httpd -D -u root -c ./*.cgi|*.cgi|cgi- - Related to the Administration Web UI.
- /usr/sbin/hostapd /var/hostapd.conf.wlan0 - Host Access Point daemon (HostAPd) is the wireless subsystem module which represents the core of the AP. It manages user-space 802.11 functions such as authentication, encryption, initializing network interface, beacon intervals, extended authorization protocol (EAP) keys, and so on. It also provides an interface into low-level drivers for management, transmission, and reception of wireless data packets. (This must be running to enable the network.)
- /sbin/udhcpc --foreground -i br0 -H Instant802-AP - DHCP client process. This must be running in order for the AP to get an IP address from the DHCP server.
- kaffe-bin -ms 500k -mx 8m -classpath /usr/sbin/rt.jar - Related to AP clustering capabilities.
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ifconfig
ifconfig br0
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Shows information about all network interfaces used by the access point, including IP addresses assigned to each interface and MAC addresses. Which of these interfaces show up depends on whether you have both internal and guest networks configured or not, and whether you have the guest network configured on VLANs or as a physically separate network. Following is a description of those that might be of interest.
- br0 - The Internal bridge, which consists of eth0 and wlan0. The IP address of the access point is provided in the output detail for br0.
- brguest - The Guest bridge, which consists of eth1 and wlan0guest.
- eth0 - The wired (Ethernet) interface for the Internal network.
- eth1 - The wired (Ethernet) interface for the Guest network
- lo - Local loopback for data meant for the access point itself.
- wlan0 - The wireless (radio) interface for the Internal network.
- wlan0guest - The wireless (radio) interface for the Guest network.
ifconfig gives the full list of network interfaces.
ifconfig br0 shows the network information for the internal interface, including the IP address for the access point.
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brctl show
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Shows bridges in a rudimentary "table" format, including bridge ID and the interfaces contained in each bridge:
- br0 - The Internal bridge, which consists of eth0 and wlan0. The IP address of the access point is provided in the output detail for br0.
- brguest - The Guest bridge, which consists of eth1 and wlan0guest.
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A Note About Using LSQL Commands to View the Configuration
The Devicescape Enterprise-Managed AP configuration system provides an SQL-like interface called Light SQL (LSQL) for retrieving and setting parameters on the access point through a command shell. The LSQL interface is primarily used by Instant802 customers and partners during manufacturing as one method of performing per-unit provisioning of MAC addresses after the initial flash image has been burned into the AP.
You can perform LSQL commands at the Busy Box prompt in a command shell via a direct serial port connection to the AP system console or a Telnet connection (as explained in the previous sections).
The AP configuration is represented in XML. LSQL commands allow you to view (and change) some aspects of the AP configuration directly.
As an example, here is an LSQL query and result showing how the version of the firmware the AP is running can be retrieved.
Query: <lsql><select><host><firmware/></host></select></lsql>
Result:
<?xml version="1.0"?>
<lsql_result><dataset><host><firmware>SM AP 1.0 (brecis build 336)</firmware></host>
</dataset><rc>0</rc><counter>1</counter></lsql_result>
A full reference of the LSQL interface to the Devicescape Enterprise-Managed AP is provided in the Developers Guide.
Details on manufacturing processes (some of which may involve using LSQL commands in scripts) are provided in the Devicescape Enterprise-Managed AP Manufacturer's Guide.
Troubleshooting
At this point, you should have a functioning access point with which to start the evaluation. If you encounter difficulty (for example, if the AP does not appear to boot properly or if you cannot see the AP on the network), please capture all information on the console (cut and paste into a text file or email) and send it to your Instant802 sales or engineering representative.
To restore original configuration settings and reboot, do the following:
- Type the following at the serial console:
rm /config/apconfig.xml
- Physically reboot the access point by activating the power button "off" then "on" again.
