ssh hangs after successfull login

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Hello. I am not sure if my problem is exactly the one mensioned in this
document but it isn't really alike

Yesterday everything was fine with my host in uk (that is half an earth
from my desktop) untill today morning I found I no longer able to login
to the host by ssh. The behavior is that after successfully
authenticated, ssh hangs up forever.

A quick google brought me to the above article saying that perhaps my
MTU has problematic settings. I got no chance to adjust MTU of the
remote uk server (becuase ssh is the only way I can get to the server,
besides a phone call to cold-boot it) to test. But I also tried to login
from 3 different linux hosts and two of them do not have NAT nor
firewall nor packet filter.

Here is the log for your reference. All 3 hosts runs Gentoo Linux

Thank you!

from host 'bossdog' (no firewall/NAT/packet filter)
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(then hangs on forever)

from host Joe (behind NAT)
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(then hangs on forever)

Re: ssh hangs after successfull login

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Adjusting the MTU on the client end should help since TCP negotiates
the "maximum segment size" (MSS) of the connection to the lesser of
client's MTU, sender's MTU and (hopefully) the path MTU (unless you've
got a firewall that mangles the MSS of outgoing connections, such as
the clampmss option on some pppoe packages).

When it hangs, if you can check the output of "netstat" for your
connection then you may see a constant or growing number in the "Send-Q"
(although in your case, the problem is probably on the server side so
that won't help).

Darren Tucker (dtucker at
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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