[Twisted-Python] Conch/SSH & Cisco IOS

Phil Mayers p.mayers at imperial.ac.uk
Thu Sep 3 05:38:26 EDT 2009


I've been having some problems using Conch/SSH to talk to the SSH server 
on Cisco IOS (specifically the netconf subsystem)

It seems that the IOS SSH server reacts badly to the following:

c: syn
s: syn,ack
c: ack
c: PSH <my version>, <my kex>
s: PSH <ios version>

i.e. IOS doesn't like being bombarded with either the version string or 
KEX before it's sent its own banner.

I've patched this locally by overriding connectionMade to be a noop and 
re-implementing dataReceived; but if I prepare a patch would it be accepted?

If not, could I prepare a patch factoring some of this logic out so it 
can be more easily overridden?

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