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MSK_222682's avatar
MSK_222682
Icon for Nimbostratus rankNimbostratus
Mar 03, 2016

Configuring 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

 

application delivery
BIG-IP DNS
dns
gtm
gtm pool member--active standby
LTM
pool selection
services and protocols

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  • Andy_McGrath's avatar
    Andy_McGrath
    Icon for Cumulonimbus rankCumulonimbus
    Mar 03, 2016

    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