Example Rip Filter; Subnets - HP 7102dl - ProCurve Secure Router Configuration Manual

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Example RIP Filter

You might want to prohibit RIP from redistributing and advertising an OSPF
default route, but you may want to allow RIP to advertise other OSPF routes.
In this example, the ACL requires only a permit statement for the allowed
OSPF route. The implicit deny any statement filters out the default route.
Enter these commands:
ProCurve(config)# ip access-list standard RIPfilterOSPF
ProCurve(config-std-nacl)# permit 10.1.0.0 0.0.255.255
ProCurve(config-std-nacl)# exit
ProCurve(config)# router rip
ProCurve(config-rip)# version 2
ProCurve(config-rip)# network 10.2.1.0 255.255.255.0
ProCurve(config-rip)# redistribute ospf
ProCurve(config-rip)# distribute-list RIPfilterOSPF out ospf
RIP applies outbound filtering to routes that are available for it to advertise.
If RIP cannot advertise the route under normal conditions, a permit statement
in the distribute-list ACL will not allow it to do so. In other words, RIP
advertises routes that meet both of these criteria:
The route is available to RIP:
• a route to a network on an interface that runs RIP
• a route redistributed into RIP
The route is selected by the outbound distribute-list ACL, if such an ACL
has been specified.
Enabling and Disabling Route Summarization for Classful

Subnets

RIP supports route summarization for classful subnets only. A router uses
summarization to advertise a route to all hosts in a class A, B, or C network
with a single routing table entry. This entry specifies the network address and
the classful subnet mask. For example, without route summarization, RIP
would need to broadcast the following:
Destination IP Address
10.2.0.0 255.255.0.0
10.3.0.0 255.255.0.0
10.4.0.0 255.255.0.0
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Next -Hop IP address
10.1.1.1
10.1.1.1
10.1.1.1
Configuring RIP
Metric
1
1
1
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