Series 3: Out of Band Management
Products Supported: AER2100, MBR1400v2, MBR1400v1, IBR11x0, IBR6x0, CBA850, CBA750B. Click here to identify your router.
Firmware Version: Up to 5.4.x - for information on upgrading firmware, click here.
Firmware version 6.0 has been released and introduces a vastly improved GUI for all current Series 3 routers. Cradlepoint has created new Knowledge Base articles with updated screen shots and instructions for the new GUI layout. As a result, this article has received its final update. To view the version of this Knowledge Base article for Firmware 6.0 and Later please click here.
This document is intended to guide an administrator through configuring the Serial Redirector feature on Cradlepoint routers for out-of-band management and troubleshooting of devices with an RS232 console interface. Once turned on, this feature is used by establishing a telnet client session with the router, which then redirects the telnet traffic to the attached console cable.
Configuration Difficulty: Intermediate
- Obtain the necessary equipment.
- IBR11x0: When initiating serial redirect from this router model, a DB9 Male to Male serial adapter is required. An example is located here. This product is not sold by Cradlepoint.
- All other Cradlepoint models: A USB-to-serial adapter that uses an FTDI chip set such is required to use the Serial Redirect feature. For more information on finding the right kind of adapter, consult the guide located here.
- Optional: 1-to-4 USB to RS232 serial adapter for support of multiple out of band devices.
- Make all the appropriate physical connections before beginning the configuration.
- Step 1: Log into the router's Setup Page. For help with logging in please click here.
- Step 2: Click on System Settings and select Serial Redirector from the drop-down menu.
- Step 3: Place a check mark next to Enabled. Wait for Server Status to become "Ready".
- Note: The Server Status will read Starting and never change if there is a problem with the detection of the adapter. This usually means the adapter is not supported by the router.
- Step 4: In the USB Serial Adapter Configuration section, set the values to match those used by your device.
- NOTE: Some routers require slightly different settings than Cradlepoint's defaults. If you find that the console window does not appear to be displaying the data correctly (such as inserting a blank row between each line of text), try changing the Cradlepoint's "Line Feed" option to a different value and then try again.
- Step 5: Click Apply.
NOTE: Cradlepoint highly recommends using the SSH-to-Serial access option instead because it is encrypted and requires a username and password. We recommend NOT using telnet-to-serial access unless the device is on a private network and not accessible from the Internet.
Using your system's telnet client software, establish a session to the Cradlepoint.
The example below shows a local connection through PuTTY.
- Specify the Cradlepoint's LAN or WAN IP address.
- (Note: the WAN connection will not work unless WAN is enabled within the router's System Settings>Serial Redirect>Telnet to Serial Configuration section. This option is highly insecure and should not be used unless the Cradlepoint router is on a private network and not accessible from the Internet.)
- Specify the telnet port specified on the router's System Settings>Serial Redirect>Telnet to Serial Configuration page.
Once the session is established, you may interact directly with your hardware.
An alternate, and secure, way to access your hardware would be to establish a SSH session to the Cradlepoint. This can be done in one of three ways:
(Click each option to open up the corresponding walkthrough guide.)
Once you have access to the router's CLI, you can issue the serial command to create a console session to your hardware.
Use the following command to initiate the serial redirect:
If you are using a 1-to-4 USB to Serial Adapter, utilize the following command to initiate a serial connection to a specific client device:
serial # - for example - serial 3
After the session is established, you will be able to access the console of your device.
Use the following commands to end the session:
CTRL + W to break connection to the device, but keep the SSH session up
CTRL + Q to break connection to the device and end the SSH session
NOTE: Only one session can be active at the a time. If a new session is opened (if the device is accessed by a different method, or by a second user) before the original one is stopped, you may receive garbled feedback.
You always want one ‘output/xmtr’ linked to one ‘input/rcvr’. The meter shows an output/xmtr with the +/- 5v (this varies by product, but tends to be +/-5v, +/-6v, +/-9v or +/-12v). Linking two xmtr’s damages nothing … but does no good & the wire voltage will be the higher of the two. Linking to rcvr’s together damages nothing, and actually can do tiny harm in that the wire acts as an antenna and one tends to ‘receive noise’.
A common symptom of a cable with TX->TX and RX->RX is the first few bytes of every message are garbled! This is caused by capacitive coupling, so as the two xmtr’s fight, the floating RX->RX line picks up enough noise to ALMOST work. This is especially common in long cables – so if someone runs a cable 100 feet and complains about errors … so it is ‘almost working’, often they have the wiring wrong. Contrary to popular belief, a backwards RS-232 cable often ‘almost works’ & rarely never works.
Q: What is the serial pin-out of the IBR1100/1150 serial port?
The serial port functions as a DCE, or a “modem port”. This is the opposite (or compliment) of the 9-pin DTE or “terminal device” port on a PC/Notebook. To connect a PC/Notebook to the IBR1100/1150, use a straight through cable. To use an existing device cable designed for a PC/Notebook, which ends in a DE9 FEMALE connector, obtain a 9-pin M-M NULL MODEM (a gender changer will NOT work – it should say Null Modem or Null Adapter on it). If you have a DTE (or PC/Notebook) cable diagram for your device, you can make a perfect cable for use with the IBR1100/1150 by swapping the pin pairs as shown in the table below, so swap TX & RX, DTR & DSR, and RTS & CTS. With a volt meter, you can also do some simple testing – any of the pins labeled OUT in the table below should measure as about -5vdc or +5vdc (not about 0v). If after your ‘changers’ and cables are in place, the final voltage at the remote end is not still +/-5v, then something is wrong in your cable. Pins labeled IN will float at around 0vdc.
|Pin||DCE Name||DTE Function||Direction (relative to IBR1100)|
Q: Is the IBR1100/1150 serial port DCE or DTE?
The serial port is a DCE or “modem port”. This is opposite (or compliment) of the 9-pin DTE port on a PC/Notebook. To connect to a PC/Notebook, use a straight through cable.
Q: My device has a serial cable for a PC – how to link to the IBR1100/1150 serial port?
Your PC cable will have a 9-pin female connector, and so does the IBR1100/1150. You CANNOT use a 9-pin M-M gender changer – that will not work! Instead, find a 9-pin M-M null modem adapter. They will be about the same size and price as the simple ‘gender changer’, but should be labeled as ‘null modem’ or ‘null adapter’.
- Reboot the hardware, including the Cradlepoint router and its client serial device.
- Reseat the connectors.
- Disable/re-enable the Serial Redirect feature on the Cradlepoint router.
- Ensure you are able to access your device’s console directly through the USB-to-Serial adapter.
- Check the RS232 settings on your device and make sure they match.
Published Date: 09/08/2015
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