Per the link you provided this looks like an Avaya bug. Did you try the
ssh -o MACs=hmac-md5 yourswitch.goes.here
If that works, you can make this automatic on your client system using a
~/.ssh/config file, or you could modify the system’s /etc/ssh/ssh_config
file for a system-wide change.
In the meantime, perhaps get Nortel/Avaya to fix their SSH implementation.
Since the last comment in that report is a year old hopefully the fix is
available from them already, and if not, well, that could be bad; there is
mention in the report of the server side crashing due to the
high-encryption options and if that’s the case the possibility of an
exploit is higher than it should probably be for a network appliance like
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…