Link definitions are arranged in an ordered list, one entry per link, which is tested from top to bottom for every packet entering or leaving the appliance. The first matching definition determines which link the packet belongs to. Within each link definition is an ordered list of rules, which is also tested from top to bottom. Each packet is compared to these rules, and if it matches one of them, the packet is considered to be traveling over that link.
Within a single rule, the fields are all ANDed together, so all specified values have to match. All fields default to Any, a wildcard entry that always matches. When a field consists of a list, such as a list of IP subnets, the list entries are ORed together. That is, if any element matches, the list as a whole is considered to be a match.
Citrix recommends port based link definitions for simple inline deployments, and IP based link definitions for all other deployments.
To configure link definitions, set parameters on the Create/Edit Link page, which you access from the Configuration: Links: Link Definition tab.