All client connection are getting closed when one of the pool member is down with MBLB profile on SIP.

I would expect that only the client connections who have been load balanced to the down pool member would be affected. If you're seeing all client connections reset when one pool member is marked down by a monitor, I would open a case with F5 Support.

 

 

SOL135 - Information required when opening a support case for BIG-IP LTM or GTM

 

https://support.f5.com/kb/en-us/solutions/public/0000/100/sol135.html

 

 

Aaron