NimbostratusIf generic hosts are added to a gtm pool, how does GTM get health of the node? Is it through polling from one of the self ips? If an alias is added to a pool instead of nodes, how does GTM get the health of the added member?
NoctilucentGTM will monitor the health of pool members based on the monitor you have assigned to the pool in question. Or if no health check is assigned at the pool level, it'll use the monitor applied to the server objects themselves. Monitor traffic is sourced from a non-floating self IP.
Alias configurations on a wide IP have nothing to do with server objects and monitoring. If you attempt to add a pool member by hostname/FQDN, the GTM will resolve that to an IP address and add it as a member.
NimbostratusI added a pool with an alias in it, there are no virtuals in the pool. The pool comes up green but nothing shows up in the tcpdump for the alias' ip, does it mean the configuration is improper? "Monitor traffic is sourced from a non-floating self IP" - what if the pool member is not among any of the subnets the self-ips belong to? Do we need addition of route to the pool member?
NoctilucentIf the pool member is not in the same subnet as the self IP, then GTM will use its routing table to determine where to send the traffic to. Do you have a default route specified on the GTM? If so, it'll use that. If not, you may need to configure one.
GTM will select a non-floating self IP as its source.
Ensure you configure your GTM pool with virtual servers so GTM has somewhere to resolve wide IP requests to.
NimbostratusI added a generic host and and route to it as there are no available corresponding self ip subnets. But the server is being marked up and down, i see something like this in the logs:
Monitor instance /Common/https xx.xx.xx.xx:443 UP --> DOWN from yy.yy.yy.yy (no route) I also see in the logs that this generic host is being checked by self-ips of other bigips added as bigip redundant sytems and being marked down by them. Any idea how to fix this?
NoctilucentThis is normal behavior if you have your GTMs setup in a sync group. You can control which GTM devices perform monitoring on the generic host by using prober pools.
http://support.f5.com/kb/en-us/products/big-ip_gtm/manuals/product/gtm-implementations-11-1-0/18.html
Or just setup the proper routing on your other GTM appliances and that should fix your issue as well.
NimbostratusNoctilucentNimbostratusNimbostratusThanks a lot Cory for your help. I figured it out, I had missed adding GTMs in the prober pools. Adding them fixed the issue.
Noctilucent