NetScaler causing NPM errors

[Patrick Leegel]

Hello,

I've set up my NetScaler with a content switching server and 3 backend Virtual Servers.
Overall access to the virtual servers work flawlessly, I can access the websites running on said servers individually.

However, one of the servers is an npm repository for our developers and as long as that one is running behind the netscaler, npm runs into a connection reset error during the building process.
This is also reflected in a trace we created during the build; several packets show the window-code "9701" which according to https://support.citrix.com/s/article/CTX200852-citrix-adc-netscaler-reset-codes-reference?language=en_US means, either side is closing the connection (See screenshot). The npm repository doesn't show any errors, neither does the NetScaler.

I've tried the following settings without success:

• Disabling HTTP Dos Protection
• Enabling/Disabling Session reuse on both the content switching server and the load balancing server behind it
  • Also changing the Time-Out to 6 minutes, instead of the default 2
• Checking and temporarily disabling rate-limiting and ACLs

As soon as we route incoming traffic of said public IP-Address to the server directly instead of the NetScaler, npm functions without errors.

More info available, if needed.