1. Application was being accessed through the LB vServer and it was not loading
2. nstrace taken on the ADC showed RST (flag:0x014) sent by VIP to the client in response to almost every GET request sent by the client.
3. ADC was sending RST with window size 9872 which means Websocket upgrade request was dropped due to websocket disabled in http profile.


 

1. Go to the LB V server which is sending reset 9872 on which HTTP profile is attached.
2. If there is no HTTP profile created, do so using article-: https://support.citrix.com/article/CTX130963/http-profiles-on-netscaler-appliance#:~:text=Select%20the%20HTTP%20Profiles%20tab,Click%20Close.
3. Edit the HTTP Profile.
   1. Enable websocket connection in HTTP profile.
   2. Click Done.

Problem Cause

Websocket connections disabled in HTTP profile