[dns-operations] Novice Question - What happens with the "source port" when a DNS resolver retries after time out?

David Ulevitch davidu at everydns.net
Fri Jul 18 20:48:58 UTC 2008

Barry Raveendran Greene wrote:
> Hi Team,
> A DNS Novice question (no access to my lab right now). 
> With the Random source port applied to a recursive server, what would happen
> when it timed out form the authority not responding? Does it use the same
> source port for the retry? Does is use a new source port for the retry? 
> I'm thinking this might be very OS/implementation based. 

You should DEFINITELY change your source port, particularly in this 


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