HP 200 Series Services And Applications page 132

Internet Protocol Routing Service
IP Filters
The relationship between the routing pool, forwarding tables, and the import
and export rules is shown conceptually below.
Figure 12. Routing Information Data Flow for RIP
Constructing RIP Import and Export Route Filters
Each filtering rule must specify an incoming/originating routing pro-
tocol. Rules in the form "Accept Network Number Mask" are invalid.
The routing pool holds one route per routing protocol per network.
If there are multiple import rules for a specific network number and
protocol, the latest routing update received using any of these rules
is the route active in the routing pool.
Most rules include a network number and mask; however, the
network number and mask are not always required.
Each import rule can contain up to three search fields; however, it
need not contain any. As a result "Ignore RIP" is a valid rule. If such a
rule were not specified, any received RIP packets that did not match
a rule would be accepted into the routing pool.
If a rule is created and contains a network address that is a superset
of an address from another rule, a packet matching the more specific
address is not affected by the rule for the less specific address. The
only exception is a rule that specifies no network address.
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RIP
Import Rules
Routing Pool
Forwarding
Export Rules
Table
RIP