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yssp
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Sep 21, 2022
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DNS Topology Load balancing

I have 4 DCs and would like to implement "Topology load balancing" at wide-ip level.

Any requests from respective DC's should go to the pools configured in those DCs.

I have acheived this routing for 4 DCs using topology records but what happens when a request comes from another region and there is no topology record for it? Does it fallback to round-robin ?

 

 

  • Hello Yssp,

    I have gone through some tests in my lab, by creating topology records that don't match my request and the responses were sent by round robin, each answer was coming from a pool. From what I understand, when a pool doesn't match with a topology record, the weight becomes 0, and that means all the pools will have equal weights ( all zeros) as no records matched, that's why the responses are coming back with round robin.

    here is an example:

    If there is no matching topology record that contains both the LDNS request source and a destination; therefore, the BIG-IP system assigns a score of zero to the pool.

    you can check some other examples in this article:

    https://techdocs.f5.com/kb/en-us/products/big-ip_gtm/manuals/product/gtm-lb-configuring-11-6-0/2.html

     

     

1 Reply

  • Hello Yssp,

    I have gone through some tests in my lab, by creating topology records that don't match my request and the responses were sent by round robin, each answer was coming from a pool. From what I understand, when a pool doesn't match with a topology record, the weight becomes 0, and that means all the pools will have equal weights ( all zeros) as no records matched, that's why the responses are coming back with round robin.

    here is an example:

    If there is no matching topology record that contains both the LDNS request source and a destination; therefore, the BIG-IP system assigns a score of zero to the pool.

    you can check some other examples in this article:

    https://techdocs.f5.com/kb/en-us/products/big-ip_gtm/manuals/product/gtm-lb-configuring-11-6-0/2.html