Issue with test netscalar REST API. We do not see issues with local REST API. Attached tcp stream from wireshark.

Netscalar ip sends syn to app server then in second line in screenshot app server sends syn and ack after which in third line netcalar ip sends client hello after this app server is sending rst. I have checked time to live for rst sent from app server fourth line and it is 128. How to trace what the issue is. Please suggest.

I checked using netstat -a if post is listening and port is listening. I checked with firewall team for any blockers between it's and they said with ips are in same subnet so no firewall blockers. No recent changes made from application end. Tried to hit the REST API url in postman local url is giving result but netscalar or user-friendly url is stuck in loading state and gives connection is rest error after a while be it in browser or postman.