53/TCP port unresponsive

Tao Lei ree at runstone.com
Sun Apr 5 15:50:42 UTC 2009

please note that the load balancers have the health checking function, which is using dns server's TCP/53, So If U stop it, load balancer will know the server down. 
  ----- Original Message ----- 
  From: Mark Koehler 
  To: bind-users at lists.isc.org 
  Cc: bind-workers at lists.isc.org 
  Sent: Friday, April 03, 2009 8:26 AM
  Subject: 53/TCP port unresponsive


        We have 4 masters (rsync'd together) and a pair of load balancers each of which distributes queries to any of the 4.  On the masters, we run Solaris 10 with BIND 9.5P1.  Recently, one of the 4 stopped using TCP on port 53, but UDP traffic continued unaffected.  What would cause the TCP port to stop?  The port was unresponsive from the backside of the load balancers, and no DNS TCP packets came from the server either.  Is there anything in BIND which would detect and block a potential DOS attack?



  bind-workers mailing list
  bind-workers at lists.isc.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/bind-workers/attachments/20090405/29d19f55/attachment.html>

More information about the bind-workers mailing list