Reaction of a host after receiving "port unreachable" icmp error msg?

[kajax01]

Hi,

Does anyone know how a host has to react when receiving an icmp error "port unreachable" say from a contacted dns server? My proxy continues asking this server every 6-10 ms quite many times.
Shouldn't it know that port 53 is unreachable and at least not try again and again every few ms?

It's a RedHat 5.7.
Thanks

 

[ryanvade]

I would imagine that there is a "Max Retry" setting somewhere. Perhaps it is set too high?

 

[kajax01]

Thanks @ryanwade!
Unfortunately I couldn't find something similar.
And udp has much less parameters to configure, I think.