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Marvin_129795's avatar
Marvin_129795
Icon for Nimbostratus rankNimbostratus
Jan 22, 2018

internal GTM integrate with external LTM

Dear All,   Someone over here some experience with integrating a GTM located in the internal network with an external LTM using the bigip add command and Iquery.   I set up a lab and had a succ...
application delivery
BIG-IP DNS
LTM
Marvin's avatar
Marvin
Icon for Cirrocumulus rankCirrocumulus
Jan 29, 2018

Hi Kevin, the issue is 100% reproducible and easy to fix. It rather looks like a bug to me.

 

  • Big IP 1: only GTM self IP 192.168.1.121 Server link 192.168.1.120
  • Big IP 2: only LTM self IP 192.168.1.120
  • Result: no virtual server or links detected.

To resolve this, I do the following:

 

  • Big IP 1: only GTM self IP 192.168.1.121 Server link 192.168.1.120 and 192.168.1.121

  • Big IP 2: only LTM self IP 192.168.1.120

     

  • Result: all virtual servers and links are being detected and eventually IP 192.168.1.121 is being removed. All newly created virtual servers on the Big IP 2 are automatically discovered as well and assigned to the link. It is so weird its seems like a bug I am using 12.1.2 HF2 in VMware. By the way I am not the only one who is able to reproduce this issue, another F5 pre-sales engineers has exactly the same findings as I do but he used version 13.

     

 

 

As you can see in the images provided of the F5 Big IP DNS is using server link 192.168.1.120 (the external LTM self IP).

 

It seems like Big IP DNS is not able to retrieve status information using only the external server link IP address. When both (external and local) are configured it will start to work properly and eventually automatically delete the internal server link.

 

I would be a good idea to investigate this issue internally at F5 because it should work using only the external server link IP address. If you need anything from me let me know I am always willing to help making things better :-)