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Iain_Ogston_377's avatar
Iain_Ogston_377
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Jul 29, 2015

Global Traffic Manager Serving wrong IP for Virtual Server

I have two GTM devices (GTM1/GTM2) in separate datacentres but synching up fine. Servers have been hosting a large number of wide IPs with no issue for some years.

 

Recently I noticed that for one virtual server the GTM2 device is serving the wrong IP (it's an old IP removed from the systems a long time ago, but would have been in the GTM config at some point in the past).

 

So for example I have a wide IP (name.company.com), pool with two servers SERVER1 and SERVER2 in the pool. SERVER1 contains a single virtual server VIRTUAL1 IP x.x.x.200 (priority 0) and SERVER2 contains a virtual server VIRTUAL2 IP x.x.x.201 (priority 1).

 

When I do nslookups on the DNS name for name.company.com over the internet to my devices I get the following response: GTM1 - x.x.x.200 , correct GTM2 - x.x.x.208 , ???????

 

If i reorder pool members then GTM2 gives the expected response x.x.x.201 and if I disable both pool members I get the expected fallback address. However, as soon as VIRTUAL1 is in the pool and enabled (as priority 0) then GTM2 starts incorrectly serving x.x.x.208 as the response to this DNS query.

 

I've tried deleting and recreating the SERVER1/VIRTUAL1 on GTM2 - makes no difference. I can't see this .208 address anywhere in my GUI config yat it keeps reappearing.

 

Can anyone tell me where this response might be coming from?

 

2 Replies

  • Further information: My GTM appears to be doing a NAT (or similar). I have deleted the above configuration and added a completely new WideIP test.company.com, with a single pool/server/virtual server with address x.x.x.200. When I query this from the problem GTM I receive the .208 address, but from other GTMs (replicated) I receive the correct .200 response. Appears this single GTM has some configuration somewhere which is translating .200 to .208 (I've checked all the areas under Local Traffix->Address Tranlation and all show as empty). Where could this NAT be coming from?