What is the primary purpose of a Subnet IP (SNIP) in Citrix ADC?

• A. It is used as the source IP for traffic to servers
• B. It is used only for management access
• C. It is used for DNS resolution
• D. It is used for VIP persistence

Answer: (A)

The Subnet IP provides the source address Citrix ADC uses when it initiates connections to backend servers. When a client hits a VIP, the ADC forwards that request to a server and the traffic appears to come from the SNIP in the servers’ subnet. The server responds to that SNIP, and the ADC handles delivering the response back to the client (often via the VIP). This works only because the SNIP is in the same subnet as the backend servers or has a direct route, allowing proper return routing. If there’s no suitable SNIP, the servers wouldn’t have a valid source address to reply to, and the connection would fail.

Other options don’t fit because the SNIP is not primarily for management access (that’s the NSIP’s role), nor is it specifically for DNS resolution (the ADC may reach DNS servers, but that’s not its core function here), and it isn’t used for VIP persistence (persistence relates to maintaining client session state, not providing a server-originating source IP).