World of EUC

Usually it is the routing table that decides.

However, by using IPSET and NET profiles, you can force traffic on a given SNIP of VIP

make sure you are also using VLANS and binding the relevant interfaces to the VLAN's and adding the SNIP under IP bindings

SNIP is used for backend traffic to servers residing only within that SNIP's subnet by default. If NS is connected to multiple subnets you *must* create a VLAN definition on the NS, create a SNIP, then bind the SNIP and interface to the VLAN to complete the association.

If you're configuring backend servers that you're not directly connected to, it will look for a SNIP in the same segment as the NSIP and try to use that by default instead. You can influence this behavior via policies and profiles but those are generally bandaids to work around an incorrect/incomplete config of the basic plumbing on the NS.

<https://docs.netscaler.com/en-us/citrix-adc/13/networking/interfaces/configuring-vlans/associate-subnet-with-Interface-using-vlans.html>