Wired Intelligent Edge (Campus Switching and Routing)

Reply
Contributor II

Laggy SSH on Aruba switches

Hey

 

I have had several TAC cases with Aruba about laggy SSH sessions to AOS swithes. There are never any solutions, and it seems like they are not able to understand why it happens. I use SSH for management of Cisco, aruba, linux and procurve and this only happens to units with ArubaOS. 

 

Anyone else seen this ?

Regards
Jon
MVP Guru

Re: Laggy SSH on Aruba switches

What laggy behavior do you see exactly? Is it a constant latency between typing a letter and seeing it back on screen? Is it that the session hangs for seconds every now and then (like there is no IP connectivity for short time)? Is it that commands, when entered, take time to process output? Is it on specific commands or large outputs?

 

This kind of issues typically has to do with something in the network like packet loss, MTU path problems or flapping interfaces (though it has been a while that I last saw network interfaces flapping).

 

If Aruba Support doesn't provide you a satisfactory solution, feel free to escalate your issue or involve your local Aruba representatives.

 

 

--
If you have urgent issues, please contact your Aruba partner or Aruba TAC (click for contact details).
Contributor II

Re: Laggy SSH on Aruba switches

To me it would seem like a drop in connectivity. But as far as I can see everything works ok, except the SSH to Aruba switches. It both hangs and has slow text input. 

 

Since this only occur on ArubaOS units and for example not on a older provision unit or Cisco unit in the same rack, Im kind of stuck. 

 

 

Regards
Jon

Re: Laggy SSH on Aruba switches

perhaps make a wireshark capture of both a constant ping to the switch and your ssh session setting up, typing a bit until the problem is known to be observed, then exit and stop the ping.

 

I think there are tools online you can anonymise/change the IPs inside the pcap if thats an issue.  The capture might shed some light on where the lag is coming from (or at least conclusively prove it's the switch switch, which gives you a bigger stick with support).

 

Occasional Contributor I

Re: Laggy SSH on Aruba switches

I can confirm that laggy behaviour. I tried different versions of ArubaOS but this issue seems to relate to any YA16.xx firmware.

Ocassionally the reaction on inputs over ssh is very slow and hangs sometimes for a second. So I would say it is more the "constant latency between typing a letter and seeing it back on screen" thing Herman mentioned. Sometimes it feels as you have to type the input twice to be recognized.

Super Contributor I

Re: Laggy SSH on Aruba switches

Are you using central authentication like TACACS?


Willem Bargeman ACMX#935 | ACCX #822

Please give me kudos if my post was useful!
If your issue is solved mark the post as solution!
Occasional Contributor I

Re: Laggy SSH on Aruba switches

In fact, I am using tacacs for ssh authentication:

 

aaa authentication ssh login tacacs
aaa authentication ssh enable tacacs

I already tried with local ssh authentication only, the issue is still the same.

Highlighted
Super Contributor I

Re: Laggy SSH on Aruba switches

This was a bug which is now fixed in the 16.08.0003 release. We experienced the same and created a case for this.

Authentication
CR_0000248908
Symptom/Scenario: When attempting to SSH to a switch where aaa authentication ssh login tacacs is configured and the TACACS server is reachable, the switch experiences a one second delay between the TACACS TCP handshake and the actual authentication request

Willem Bargeman ACMX#935 | ACCX #822

Please give me kudos if my post was useful!
If your issue is solved mark the post as solution!
Occasional Contributor I

Re: Laggy SSH on Aruba switches

I have seen that in the release notes and tried the 16.08.0003 release as well. But this laggy behaviour occurs after the tacacs login, even on this latest release. While configuring or troubleshooting the reaction on every typed character is sometimes incredible slow (the delay between typing and seeing the character typed in the ssh windows). My guess is that the ssh process is way under-priorized.

Super Contributor I

Re: Laggy SSH on Aruba switches

What we have seen is a delay in the TACACS authorization request. Every time you type a command it is validated by the TACACS server.
I haven't test the new release so I'm not sure if it is fixed.

Willem Bargeman ACMX#935 | ACCX #822

Please give me kudos if my post was useful!
If your issue is solved mark the post as solution!
Search Airheads
cancel
Showing results for 
Search instead for 
Did you mean: