Q: What is the Difference Between NetScaler MIP and SNIP?

A: Mapped IP (MIP) is essentially a default (Subnet IP) SNIP. NetScaler looks in its routing table for the best route to the destination. If it finds one, it uses the SNIP associated with the route. If it does not then NetScaler uses the MIP, which usually has a route to the default gateway. However, you do not need a MIP. Make sure you have an SNIP on the same network as your default gateway (route 0.0.0.0). SNIPs are also known as interface IPs. Every interface/VLAN you plug into the NetScaler needs a SNIP associated with that interface/VLAN.

Additional Resources

Citrix Discussion - Difference with SNIP / MIP / NSIP