At Thu, 15 Jan 2015 13:29:15 +0000, mick wrote:
On Thu, 15 Jan 2015 13:09:08 +0000 Brett Parker iDunno@sommitrealweird.co.uk allegedly wrote:
On 15 Jan 10:06, Richard Lewis wrote:
Any suggestions what else could be wrong? Or is it really that all the servers need to have 'UseDNS no'? And if so, what has changed about them all to make this necessary? Or could it be something to do with my network set up?
If UseDNS no fixes it it suggests that you've got broken reverse DNS.
Out of interest, are the hosts that you're trying to connect to over IPv4 or IPv6? And have you got working reverse DNS on the IP that you're connecting from? The ssh daemon by default does a reverse lookup on the IP, and so will stall if there isn't one for a bit.
Thanks,
And a good test for that is to add the IP address of the client to the hosts file of the server and ensure that the order of DNS resolution (/etc/nsswitch.conf) is files first, then DNS.
Thanks, both. It seems this is a reverse DNS problem. I'm making my SSH connections from a host on the gold.ac.uk network, but trying reverse DNS lookup of the IP address of that host results in SERVFAIL after a 5-10 second delay. I asked our departmental system administrator about it and he's escalated to the College IT services. I also checked that connecting from a host outside the College network does not result in a delay.
Richard