[H-GEN] Is this a DNS configuration problem?

[Edwards_Ewan_B at cat.com]

On Wednesday 10 March 2004 12:16, Trent Waddington wrote:

> >ssh -l <userid> <hostname>
>
> Should fail but it tries <hostname>.yourdomainname after it tries
> <hostname> so it works.. the looking up of <hostname> takes a long
> time to fail.

Hhmmm ... 
The response to a ping of either <hostname> or <hostname>.<domainname>  
is (almost) instant in both cases.  From that I'd guess looking up 
<hostname> either doesn't fail, or ssh uses a different mechanism for 
name lookups.


>
> >ssh -l <userid> <hostIP>
>
> Fast because no DNS is involved.

Agreed


>
> >ssh -l <userid> <hostname>.<domainname>
>
> Fast because a successful DNS is fast.. or because the
> <hostname>.<domainname> is cached (probably as a result of doing
> the above).

I'm leaning toward "successful DNS is fast" as the reason.  This is 
because running the first case (ssh -l <userid> <hostname>) five 
times in less than a minute achieves the same delay every time, so 
its not likely to be using cached information.


>
> In any case, I would suggest adding:
>
> <hostname>   <hostIP>
>
> to /etc/hosts and forget about it.

Not really an option as there are a number of machines involved (not 
just these two) and they're all dhcp clients.  The main purpose of 
which is to avoid doing anything with hosts files on any of the 
platforms (mixture of Windows and Linux).  The DNS server is 
configured to allow dynamic updates from the DHCP server.


BTW
The different Linux boxes are running openssh 3.1, 3.5, or 3.6, all 
configured to use protocol version 2.  Also, some of the client boxes 
are Windows 2k & XP running Putty 0.53b.