1100TG terminal server ssh console sessions hang

[lcaruso]

With these new Cisco 1100 TG terminal servers, I have been stuck on this for weeks troubleshooting and trying different configs. Have reviewed dozens of online forum posts and technical notes. 

Console sessions hang after entering SSH password. It just hangs after the password is entered, and shift-ctrl-6 x works fine and clear line 2 hangs up the connection fine, so the issue is not with SSH but with the negotiation of the console session after authentication. 

Have tried every flow control, stop bits, and transport input parameter combinations under the line config. Have tried a new octal cable. Have tried different target device console ports. Nothing works. 

[Reza Sharifi]

You maybe encountering a bug in the IOS you are using. Have you looked into an upgrade option?

HTH

[lcaruso]

Hi Reza,
Thanks for your suggestion. We are running the latest version as of a few days ago, Cisco IOS XE Software, Version 17.06.05
I have considered downgrading but have not done this as of yet. I have a TAC case open, actually this is the 2nd TAC case.
The first engineer could not find any issues with the config, but maybe the 2nd engineer will find a solution.

[Reza Sharifi]

Hi,

Hopefully TAC can reproduce the problem and suggest a different version. Anything in the log while this is happening?

Also, I know you already purchased this, but in the future and when you are fed up with Cisco's terminal server solution, you may want to look at this. It is basically set it and forget it. It is been working flawlessly for me for almost 8 years now.

https://www.perle.com/products/terminal-server.shtml?gclid=Cj0KCQjww4-hBhCtARIsAC9gR3aJh-MVUqpmE9VY7HV0et5gzdhGQ995OnatG2dvieWRiS__6l8Ap9kaAkinEALw_wcB

HTH

[lcaruso]

I hear you. We waited a year for these 1100TGs to ship, and in the meantime we got some Black Box units that work great and have me wishing we did not go down this path.

[jframe]

If you have been experiencing issues with console sessions hanging after entering SSH password on Cisco 1100 TG terminal servers, despite trying different configurations and troubleshooting steps, it is possible that there may be an issue with the terminal server itself or the target device being accessed.

Here are some additional troubleshooting steps you can try:

Check for any firmware or software updates for the Cisco 1100 TG terminal server. Updating to the latest firmware or software version may resolve any known issues or bugs that could be causing the console sessions to hang.

Try accessing the target device directly through its console port, bypassing the Cisco 1100 TG terminal server. This will help determine whether the issue is with the terminal server or the target device being accessed.

Verify that the target device console port is configured correctly. Make sure that the console port is set up to use the correct speed, flow control, and other parameters.

Check that the target device console port is not being used by another session. If there are multiple sessions trying to access the same console port, it can cause conflicts and result in console sessions hanging.

Check that there are no network connectivity issues between the Cisco 1100 TG terminal server and the target device. Verify that the network configuration settings are correct and that there are no firewall or access control issues.

[lcaruso]

Update: I figured out the issue that led me to believe the unit could not function at all.

Solution: Do not use line 2, aka tty 0/1/0

All of the lines subsequent work fine, line 3 tty 0/1/1, line 4 tty 0/1/2, etc

It does not matter which SSH port number I map to line 2 tty 0/1/0, it never works. Likewise, it does not matter which SSH port numbers I map to the subsequent lines, they always work. 

Both 1100TG units demonstrate exactly the same behavior

[Richard Burts]

Thanks for the update. Very interesting that the issue was a particular line. Glad that you were able to find the solution to your own problem.

[Reza Sharifi]

A very strange issue. Thanks for the update!

[lcaruso]

Indeed, it was. I tried it on three different code versions including the very latest ED release. Another way of verifying was: since rotary 1, assigned to the first line, did not work, I assigned rotary 2 to the first line instead, and it still failed, but when rotary 2 was assigned to the 2nd line, it worked fine as did all other lines. Seems like an off-by-1 error seen in programing practices, but even harder to explain is why octal cable breakout 1 is getting mapped to the 2nd line. 

[Reza Sharifi]

It makes you wonder if Cisco really tests the software before putting it out there for public to use. 

Even though Cisco has been in the business much longer than most of its competitors, software and programming have sadly never been a strong suit for them. And I believe it will become even tougher because of how the market has changed so drastically in the last 8 to 10 years. More and more is being taken over by cloud service companies.