NimbostratusBIG-IP GTM can "talk" to non-F5 servers, but not nearly with the same level of accuracy, flexibility, and granularity as it does with BIG-IP LTM systems. iQuery is used between GTM and LTM and the statistics provided go down to the virtual server level; SNMP can be used between GTM and non-F5 servers when an SNMP-type monitor is applied to the server. But the information collected is only at the server level, and can include measurements such as memory, CPU, and disk space utilization or throughput rates. However, a lot depends on the server's configuration. GTM's support for this is limited, and is based on the type of server you select when you define the server to GTM. (You've probably noticed that, other than "Generic Load Balancer" or similar, there are not a lot of more modern server types.) There are also potential pitfalls when using an SNMP monitor on a non-F5 server (as compared to a bigip monitor on an F5 server), not the least of which is this: If an SNMP-type monitor fails, all the virtual servers hosted on the associated server will be marked as unavailable.
By default, GTM delegates monitoring activities to a BIG-IP system that resides in the same data center as the monitored resource. (This behavior can be overridden with prober pools.) The static self IP addresses on GTM and other BIG-IP systems are used for monitoring activities.
