On 14.05.2006, at 23:41, Manuel Bouyer wrote:

> On Sun, May 14, 2006 at 11:08:16PM +0200, Andreas Neth wrote:
>> [...]
>> ping from seshat to isis is currently without delay, vice-versa is
>> delayed.
>>
>> seshat# ping isis
>> PING isis (isis ): 56 data bytes
>> 64 bytes from isis : icmp_seq=0 ttl=255 time=0.280 ms
>> 64 bytes from isis : icmp_seq=1 ttl=255 time=0.250 ms
>> 64 bytes from isis : icmp_seq=2 ttl=255 time=0.265 ms
>>
>> isis# ping seshat
>> PING seshat (seshat): 56 data bytes
>> .....(imagine 20secs delay here)
>> 64 bytes from seshat: icmp_seq=0 ttl=255 time=45.535 ms
>> 64 bytes from seshat: icmp_seq=1 ttl=255 time=0.332 ms
>> 64 bytes from seshat: icmp_seq=2 ttl=255 time=0.323 ms
>
> There doesn't seem to be packet loss, nor delay once ping starts
> transmitting. Could you try to ktrace ping to see what it's doing  
> in these
> 20 seconds ? Could it be a DNS issue ?

aaah, thanks!

re-checking resolv.conf revealed some machines having a dead DNS listed.

I usually issued ping with the real IP to work around possible DNS- 
errors, but it apparetly _reverse-maps_ the IP. (which is not  
directly visible in ktrace...)
So, those 20 seconds ping took, were the timeout until querieng the  
next, working DNS. Guess NFS does the same (as well as ssh, and others).

After removing the faulty DNS from the rest of the machines,  
everything seems to work now.

Thanks for your patience