Forum Discussion
MSK_222682
Nimbostratus
NimbostratusConfiguring GTM to provide DNS service based on port
Hi,
I have a scenario, wherein we have to load balance an app between two DCs which are geographically apart. Now, this app would listen on multiple ports viz., 80,4500,4510 etc., in total around 10 ports.
On the LTM level of both locations, I would configure corresponding VS's with same IP address but with different ports as requested. But I'm confused on how to load balance the app based on specific port on GTM level cos all I know is GTM would provide DNS service and sends the requests to the active LTM in the pool (pool configured under Wide IP).
Could one of you suggest me on this or is there a way to write policies on GTM to check for which port the requests coming in and direct to certain pool (if I configure pool based on port) in which only one VS LTM would be active.
Br,MSK
Andy_McGrathCumulonimbus
Quick answer, no.
GTM is DNS based only for all queries so client will query its local DNS server, this DNS server will then forward the query to the GTMs but this query is for hostname (actually FQDN) lookup so no part of the original clients HTTP request is sent to their local DNS server or the GTM.
The only real option you have is to add all your LTM virtual server into GTM (as virtual servers) and create a Dependency between them so if one of them fails GTM will mark all of them down, see the following link for 11.5.x:
GTM: About virtual server dependency