GTM health monitor fails on pool, but not on member.

I am running GTM 11.4.1 HF1.

 

If I assign the default HTTP health monitor to a GTM pool, the pool goes red. If I remove the pool health check and add the HTTP health monitor to the member that's in the pool, the pool goes green.

 

The GTM has no problem making a telnet connection on port 80 to the member. It can ping and tracert to the member without problem.

 

This behavior happens for any pool and member combination. Is this expected behavior? Why can I not set a pool health check and have it work correctly? I spend most of my time in LTM and am accustomed to LTM behavior.

 

thanks!