[c-nsp] putty SSH errors on IOS-XR 5.1.1

[Javier Henderson (javier)]

> On Jul 23, 2014, at 8:43 AM, Vinny_Abello at Dell.com wrote:
> 
> Hello,
> 
> I've got a pair of new ASR-9904 routers running IOS-XR 5.1.1 to which I've applied SP2. Both pre and post-SP2 I keep having connectivity problems with my normal SSH client, putty on Windows. When a lot of data is being sent at once from the router to my client, putty will disconnect and give me the error: "Disconnected: Server protocol violation: unexpected SSH2_MSG_CHANNEL_FAILURE packet". I can connect to the same device all day long using OpenSSH 6.2p2 from a FreeBSD machine with no issues. Has anyone else seen this issue and possibly have a workaround or settings to tweak in putty to prevent it from constantly being disconnected? FWIW, I've experienced similar incompatibilities with putty in the past with other network vendors, but it seems the network vendors always acknowledge the issue on their end and fix it in future code that they release rather than a fix for putty coming out to address it. I'm suspecting putty may be overly strict with certain protocol compliance!
> . Regardless, it would just be nice to use my tools that I manage all my other devices with and not have to deviate to a workaround. I do have some ASR-9001's also in production but they are still running older 4.2.3 code and I've never had this issue on them.

Hi Vinny,

On PuTTY go to:

Configuration -> Connection -> SSH -> Bugs

And set “Chokes on PuTTY’s SSH-2 ‘windadj’ requests” to On (the default is Auto).

Javier Henderson
javier at cisco.com