Forum Discussion

Thomson_Thomas's avatar
Aug 17, 2021

F5 DNS resolve internal wide ip only

Im trying to set up a new wide ip and pool set for topology. Internally this works fine however externally lookups are coming up with the internal address. I would like to stop this from happening.


wide ip is


topology rules are

IP Subnet is Pool is APP-Internal


But this isnt stopping the external lookup. Please let me know what can be done to fix this issue.

2 Replies

  • Have you tried creating a second topology rule with the external address? Otherwise, if this is your only answer, that may be where the problem lies. The topology records work as a popularity contest, not necessarily the first one that matches.


    Alternatively, if you are getting multiple answers, have you got "Return to DNS" configured as the Fallback load balancing method? In that case, the answer is likely to come from your Bind configuration, which contains roughly the same records as your WideIP's. You can also check which load balancing method gets used via the Statistics page of the WideIP. In that case, switching the Fallback method to None should do the trick.


    Hope this helps.

    • Thanks for the response Alex.

      I added a topology rule below the private listing to match external ips so ip address is for source and destination.

      I also changed the pool preferred load balancing to topology and alternate and failback to none.

      However im still seeing the internal address being advertised externally, and now the result is switching from dc1 vip to dc2 vip. Which are part of the same pool. Id like to prefer dc1 internally and not have any result externally. The external lookups are coming up as using the preferred load balancing method. Please let me know if you have any suggestions. Also when i change the secondary method to drop external lookups stop but internally it selects either the dc1 vip or the dc2 vip.