Since I upgraded most of my machines to the latest version of my linux distro I cannot ssh to either of my 2820 routers.

I can ssh to anything else.
I can telnet to the 2820s
I can ssh from an older system.

The crucial point is the version of ssh: -

Older system which works: OpenSSH_4.6p1, OpenSSL 0.9.8e 23 Feb 2007
Newer system which fails: OpenSSH_5.8p1, OpenSSL 1.0.0c 2 Dec 2010

Code:

...@39net-w04> ssh 192.168.1.10 ...@192.168.1.10's password: [b]PTY allocation request failed on channel 0[/b] ...@39net-w04>

Anyone have thoughts, ideas, workarounds, similar experience?

Ah ha!! Found the workaround, prevent ssh trying to allocate a pty.:

Code:

ssh -T

Still questions remain, why has it changed, is it ssh's fault or the 2820 ssh implementation?
Also what does not allocating a pty really mean in this context of a router command line?