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dhsmith_116072's avatar
dhsmith_116072
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Nov 02, 2013

How can I automatically mark pool addresses down when one ISP fails with GTM acting as Link Controller with multiple ISP's?

We have LTM monitoring individual pool members and GTM finds out if the pool is available only by asking LTM - this is fine. GTM has multiple public IP's to give out for each ISP providing service. S...
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Tom_G__134358's avatar
Tom_G__134358
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Nov 27, 2013

Hi,

 

I have a similar issue. I kind of managed to get it working using :

 

  • links with custom monitors (based on gateway ICMP) pinging google DNS servers via the link.
  • explicit-link-name to explicitly attach the link to each GTM virtual server associated with the ISP link. (see Sol13827)

     

    It works fine with two remaining issues :

     

  • in my case, some virtual servers are automatically attached to the link (even though I did not specify an "explicit-link-name" value) because they belong to the same subnet. So I'll have to create another link and attach them to it.
  • I still have one virtual server that does not follow the status of the link although it is configured in a similar way. I.e the link is marked as down, most virtual servers associated with the link are brought down, but this particular one stays up. Looks like a bug to me, and I have an open case with F5.

     

    Also what bugs me is that all service provisioning can be done from the WebUI, but the "explicit-link-name" needs to be done in TMSH... not optimal.

     

    Your last post on this topic was 3 weeks ago. Did you manage to get it working ? Is there anything you can share ?

     

    Thanks

     

    Tom

     

  • dhsmith_116072's avatar
    dhsmith_116072
    Icon for Nimbostratus rankNimbostratus
    Nov 27, 2013
    Hi Tom - thanks a LOT for your information. I'll have to look into the explicit-link-name command, I'm unfamiliar with it. I am still slightly amazed that this isn't a very common scenario out there and that there isn't a simple webUI configuration option (or at least examples) for dealing with multiple ISP's I have not been able to work on this with the transparent monitoring configuration because I'm still working though another problem trying to get a happy HA pair of LTM's on 11.3 to be just as happy on 11.4.1 When I get back to it I will post whatever I learn here since this should be the best resource we have for sharing. To recap my objectives: 1. minimum monitoring (ie. only one device should be doing upstream polling, pinging, whatever, not 500 virtuals) 2. LTM AND GTM must BOTH modify their behavior as a result (ie. LTM must not use the "down" ISP for outbound traffic initiated from inside AND GTM must stop giving out IP's of the "down" ISP. Return traffic from outside will behave nicely automatically thanks to auto-last-hop magic) Thanks again - wish there were more people dealing with this. More later.... --Dave