: :corruption! : : :http://mina.naguib.ca/blog/2012/10/22/the-little-ssh-that-sometimes-couldnt.... I ran into a similar issue with a customer just a few days ago! The customer's theory was that there was something badly wrong with their dorky gateway/switch (which we sold and support <sigh>). ssh was timing out, with a SSH2_MSG_KEX_DH_GEX_GROUP hang/failure during the ssh protocol exchange. Based on that, some wireshark captures, and and stray Google droppings, I advised them to ratchet down the MTU to make things work. Through bisectional MTU settings and pinging, we arrived at an MTU of 850. And I initially started cursing at the switch (because that helps move packets, really :) ). Turns out -- the ssh server in question was running RHEL 5.x Linux, and that was the key. Even though "ip route show cache" looked sane, "ip route flush cache" (which I had them run, just on a lark) made the problem go away. So it probably wasn't my switch (unless it had done something untoward in the distant past that induced some weird Linux stack bug). I'm mostly posting this because I was wondering if anyone else had run into an MTU of 850 before. Is that a "magic number" that rings any bells (or perhaps has seen the Linux route cache behavior I did). -Mike -- Michael J. O'Connor mjo@dojo.mi.org =--==--==--==--==--==--==--==--==--==--==--==--==--==--==--==--==--==--==--= "It is now the age of now." -Non Campus Mentis