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sshd delay in login - over one minute!

 
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Occasional Visitor

sshd delay in login - over one minute!

Trying to troubleshoot a vexing issue. I'm attaching the output of the command 'time ssh -vvv . When I finally do connect, I immediately D to end the timing.

The typical procedure I have to go through to access these prod boxes is to first initiate a VPN to a windows "jump server" - then initiate a puTTy session to the unix box.

For this test I ssh'd from one box to the other to eliminate the jump server variable and also to time the connection.

I'm new to this infrastructure, which appears to be propped up by windows admins. Can anyone look at the output and tell me where it's hanging please?
4 REPLIES 4
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Honored Contributor

Re: sshd delay in login - over one minute!

> [...] Can anyone look at the output and
> tell me where it's hanging please?

I don't see how. Is there anything in that
log which would provide any timing info?
Aren't you looking at it when it hangs?

One frequent problem which causes connection
delays with SSH (and Telnet, ...) is a
reverse DNS look-up problem, details of which
appear in many old threads which could be
found by a Forum search for keywords like,
say:

ssh slow
or:
ssh delay
Highlighted
Honored Contributor

Re: sshd delay in login - over one minute!

Another cause of delay is a huge /var/adm/wtmps, or maybe /var/adm/wtmp.
An ssh-connect reads the complete file, so the bigger these files, the longer a login takes.
You can empty the files (cat /dev/null > /var/adm/wtmps), but do not remove them.
Advisor

Re: sshd delay in login - over one minute!

# fwtmp -c < /var/adm/wtmp > /tmp/wtmp.backup
# > /var/adm/wtmp

rgds,
Laco
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Advisor

Re: sshd delay in login - over one minute!

Hi

is the delay is happening affter issue password or delay starts before prompting for password ?

BDD