[Twisted-Python] Conch/SSH & Cisco IOS

Phil Mayers p.mayers at imperial.ac.uk
Thu Sep 3 18:33:22 EDT 2009

Pavel Pergamenshchik wrote:
> On Thu, Sep 3, 2009 at 2:38 AM, Phil Mayers<p.mayers at imperial.ac.uk> wrote:
>> All,
>> I've been having some problems using Conch/SSH to talk to the SSH server
>> on Cisco IOS (specifically the netconf subsystem)
> ...
>> i.e. IOS doesn't like being bombarded with either the version string or
>> KEX before it's sent its own banner.
> What version of IOS, what router model and what version of Twisted are

12.2(33)SXI2 on 6500/sup720

Twisted version is either 2.5.0 or 8.2.0 - same results with both.

It does seem to be an IOS bug; it doesn't happen against some of other 
other kit (e.g. 3750s running 12.2(46)SE)

> you using? Can you post the ssh-related parts of your router
> configuration?

There is none; it's using plain defaults i.e. boot the box, run a 
"crypto key generate rsa", SSH is enabled.

Sigh. I am really not looking forward to opening a TAC case here.

"What SSH client are you running?"
"Twisted Conch"
"Is that a windows application"
"No it's an SSH library"
"We support Putty"
"It's a library"


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