HP 200 Series Services And Applications page 131

Internet Protocol Routing Service
IP Filters
IP Filters
Routing Filters
The HP routers support import and export route filters to allow you to
modify the order of precedence for deriving routes to a given destination
network. Import filters restrict the input of routing information about a
given destination by a particular routing protocol. Export filters restrict the
output of routing information about a given destination by a particular
routing protocol. (Refer to the description of the routing pool, "Preference
and the Routing Pool", within the preceding section on static routing.)
govern the addition of new routes to the routing
RIP import rules
pool. RIP maintains a distinct set of import rules. For example, upon
receiving a new routing update, RIP consults its specific import rules to
validate the information before inserting the update in the routing pool.
Import rules contain search information (used to match fields in incom-
ing routing updates) and action information (used to specify the action
to take with matched fields).
RIP export rules govern the propagation of routing information by
RIP. RIP maintains a distinct set of export rules. For example, when
preparing a routing advertisement, RIP consults its specific export rules
to determine whether routes to specific networks are to be advertised
and how they are to be propagated. Export rules contain network
numbers (used to associate a rule with a specific network) and action
information (to specify a route propagation procedure).
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