Forum Discussion

Robert_Roman_14's avatar
Robert_Roman_14
Icon for Nimbostratus rankNimbostratus
Mar 27, 2014

Send traffic to second wide ip if the first wide ip fails

Hello all. My question is this: I have two wide IPs on my GTM. VCC.test1.com and VCC.test2.com. What we want to be able to do is have all traffic go to VCC.test1.com. However, if any part of VCC.test1.com fails and the Wide IP is marked down, we want it to automatically send all traffic to VCC.test2.com. I am new to the management of F5 and would assume that since I have not found anything explicitly saying what settings to change to accomplish this, this may be able to be handled with an iRule. If someone could enlighten me on whether or not this will be able to be accomplished, I would greatly appreciate it.

 

APM
application delivery
availability
BIG-IP DNS
design
devops
iRules
security

9 Replies

Sort By
  • uni's avatar
    uni
    Icon for Altostratus rankAltostratus
    Mar 27, 2014

    GTM is about resolving domain names to IP addresses, so on it's own I don't think you can do what you are saying. However, what might meet your requirement is to configure a fallback IP in your GTM pool with the address of an LTM virtual which issues a redirect to vcc.test2.com

     

    • Robert_Roman_14's avatar
      Robert_Roman_14
      Icon for Nimbostratus rankNimbostratus
      Mar 27, 2014
      So if I am understanding you correctly, I could add a fallback ip on the VCC.test1.com pool that points to the virtual server of vcc.test2.com so that if all of the virtual servers that point to vcc.test1.com in the pool are unaccessible, it will be picked up by default an thus route to vcc.test2.com?
    • uni's avatar
      uni
      Icon for Altostratus rankAltostratus
      Mar 27, 2014
      That's not what I meant, but if you only want to resolve to the addresses of test2, but don't care that they receive requests with the test2 host header, then the better way to do it is to have a pool of test1 servers and a pool of test2 servers. Configure the wideip with global availability with the preference to the test1 pool.
    • Robert_Roman_14's avatar
      Robert_Roman_14
      Icon for Nimbostratus rankNimbostratus
      Mar 27, 2014
      What they want is to have everyone go to vcc.test1.com. If at any point that is unreachable, they want people to automatically be routed to vcc.test2.com and like you said, it doesnt sound possible to accomplish on the wide ip level. I dont think that the fallback ip scenario is something that they will want to do, but it is an option at least. Thanks for the information!
  • uni_87886's avatar
    uni_87886
    Icon for Cirrostratus rankCirrostratus
    Mar 27, 2014

    GTM is about resolving domain names to IP addresses, so on it's own I don't think you can do what you are saying. However, what might meet your requirement is to configure a fallback IP in your GTM pool with the address of an LTM virtual which issues a redirect to vcc.test2.com

     

    • Robert_Roman_14's avatar
      Robert_Roman_14
      Icon for Nimbostratus rankNimbostratus
      Mar 27, 2014
      So if I am understanding you correctly, I could add a fallback ip on the VCC.test1.com pool that points to the virtual server of vcc.test2.com so that if all of the virtual servers that point to vcc.test1.com in the pool are unaccessible, it will be picked up by default an thus route to vcc.test2.com?
    • uni_87886's avatar
      uni_87886
      Icon for Cirrostratus rankCirrostratus
      Mar 27, 2014
      That's not what I meant, but if you only want to resolve to the addresses of test2, but don't care that they receive requests with the test2 host header, then the better way to do it is to have a pool of test1 servers and a pool of test2 servers. Configure the wideip with global availability with the preference to the test1 pool.
    • Robert_Roman_14's avatar
      Robert_Roman_14
      Icon for Nimbostratus rankNimbostratus
      Mar 27, 2014
      What they want is to have everyone go to vcc.test1.com. If at any point that is unreachable, they want people to automatically be routed to vcc.test2.com and like you said, it doesnt sound possible to accomplish on the wide ip level. I dont think that the fallback ip scenario is something that they will want to do, but it is an option at least. Thanks for the information!
  • Mohamed_Lrhazi's avatar
    Mohamed_Lrhazi
    Icon for Altocumulus rankAltocumulus
    Mar 27, 2014

    A wide_ip resolves a DNS name to the IPs of virtual servers found in GTM pools... A wide_ip can have two pools, and only use the first pool, unless it down, then use the second pool. I think it's called "global availability"... so you could add the pool of the other wide_ip, to the first. No?