Forum Discussion

sathish_2826's avatar
sathish_2826
Icon for Nimbostratus rankNimbostratus
Apr 24, 2020

DNS query for GTM & LTM based URL's

Hi there, I have couple of questions, my URL is load balanced between two LTM's and one GTM on top of it, so when i hit the application in the browser, it goes to DNS, DNS delegates to GTM for reso...
application delivery
BIG-IP
LTM
cjunior's avatar
cjunior
Icon for Nacreous rankNacreous
Apr 24, 2020

Hi,

If your VS goes offline, the customers who got the previous available IP will fail until the TTL expire or cache flushes.

You should consider setting lower values ​​for TTL to have high availability for your application.

 

Regards

sathish_2826's avatar
sathish_2826
Icon for Nimbostratus rankNimbostratus
Apr 29, 2020

One last question, If i enable the wideip persistance ttl to 3600 seconds (default), and i have one pool associated to it, which contains 2 LTM vip's, inside the pool, i set the TTL to 30 seconds, and i select round robin,

 

Please help me understand this, so this means, wideip persistance ensures i get the same pool member for 3600 seconds for DNS queries, and pool TTL ensures that even though i persist for the same IP for 3600 seconds, the client must do a fresh DNS query every 30 seconds so that if the member that i was persisted to went down, the over all GTM persistance gets rewritten with the new member,

 

Can you confirm this please.