Why TCP port is required for Wide IP Pool members

Let me see if I can take a crack at this.

 

The BIG-IP GTM typically uses 1 or more Virtual Servers ( IP and port, even if the port is 0) whether BIG-IP or anything else as part of the GTM decision tree to decide on how to respond to a DNS based question. There are ways to use GTM to respond with a simple IP address, but in my opinion a lot of the real power that comes from GTM is from the health monitoring aspect of the product.

 

If you want the GTM to utilize the monitors for a virtual server in the GTMs decision making process you need an IP and service port for the service the GTM is monitoring.

 

How if I have 1 IP but with 2 or more TCP service ports?

 

When I create a GTM Wide IP Pool, I need to choose one port but this causes some problems, here's an example:

 

Say I have 10.1.0.100 and my LTM has port 80 and port 443. If I add 10.1.0.100 : 443 as a pool member in the GTM, then should port 80 fail - the GTM wouldn't know because the GTM is only receiving information about 443 from the LTM. And conversely, if port 443 fails - the GTM will mark 10.1.0.100 as unavailable even when port 80 is still up.

 

How do I get the GTM to not mark the IP as unavailable if there are still other service ports up?