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Brian_Saunders1's avatar
Brian_Saunders1
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Nov 12, 2013

GTM Wide IP Topology Based Load Balancing

Hello,

 

I'm interested in creating an active / active GTM record that load balances at the wide IP level based on typologies. We already have a small implementation in place where I work that was setup before my time, but I've been getting inconsistent results. Basically I have a wide IP created with two pools and only one server in each pool. There is a topology record created as follows:

 

![Image Text](/Portals/0/Users/026/14/12314/11-12-2013 8-22-09 AM.png)

 

My source IP is 10.67.36.12 so based on the topology record defined above I should always get directed to Virtual-CGS Topology, but when I test it out I'll sometimes go to Virtual-CGS and sometimes Virtual-PD. From reading documentation it reads like this type of topology setup is more for load balancing at the pool level and not wide IP level? Is that the case?

 

Cheers,

 

Brian

 

application delivery
availability
BIG-IP DNS
design
gtm
topology
wide ip

5 Replies

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  • Brian_Saunders1's avatar
    Brian_Saunders1
    Icon for Altostratus rankAltostratus
    Nov 12, 2013
    Sorry, image didn't load as expected so here's the topology record that I was speaking about: IP Subnet is 10.80.0.0/12Data Center is Virtual PD- Topology10 IP Subnet is not 10.80.0.0/12Data Center is Virtual CGS-Topology11
  • Jason_40733's avatar
    Jason_40733
    Icon for Cirrocumulus rankCirrocumulus
    Nov 12, 2013

    Keep in mind. The source IP is not going to necessarily be the source IP of a client, but the source-IP of the DNS resolver being used by the client. If your 10.67.36.12 is querying a DNS resolver to get the record, it will be the IP of the DNS resolver that will be used for load balancing.

     

    Anyways, to your issue. It "may" be because your load balancing is defined as "pools" but your topology is defined as "Data Centers". I'd try adjusting the topology records to be the more granular 'Pool is blah-blah' instead of 'Data Center is ho-ho' and see if that works.

     

    • Brian_Saunders1's avatar
      Brian_Saunders1
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      Nov 12, 2013
      I pulled a packet capture while performing the DNS query. The DNS query went to the same DNS resolver each time but the DNS resolver didn't always respond with the same result. I'll try modifying the topology records to reflect the pool instead of data center. Is it possible to add this without impacting the existing topology setup? Do I just need to create two more data centers and change my servers to those so they won't fall into the existing topology rules?