Route Filtering; Route Summarization; Route Redistribution; Chapter 12 Configuring Rip - Cisco Nexus 7000 Series Configuration Manual

Chapter 12 Configuring RIP
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
You can use split horizon with poison revers to configure an interface to advertise routes learned by RIP
as unreachable over the interface that learned the routes.
split horizon with poison reverse enabled.
Figure 12-1
router C learns about route X and advertises that route to router B. router B in turn advertises route X to
router A, but sends a route X unreachable update back to router C.
By default, split horizon is enabled on all interfaces.

Route Filtering

You can configure a route policy on a RIP-enabled interface to filter the RIP updates. Cisco NX-OS
updates the route table with only those routes that the route policy allows.

Route Summarization

You can configure multiple summary aggregate addresses for a specified interface. Route summarization
simplifies route tables by replacing a number of more-specific addresses with an address that represents
all the specific addresses. For example, you can replace 10.1.1.0/24, 10.1.2.0/24, and 10.1.3.0/24 with
one summary address, 10.1.0.0/16.
If more specific routes are in the routing table, RIP advertises the summary address from the interface
with a metric equal to the maximum metric of the more specific routes.
Cisco NX-OS does not support automatic route summarization.
Note

Route Redistribution

You can use RIP to redistribute static routes or routes from other protocols. You must configure a route
map with the redistribution to control which routes are passed into BGP. A route map allows you to filter
routes based on attributes such as the destination, origination protocol, route type, route tag, and so on.
For more information, see
Whenever you redistribute routes into a RIP routing domain, Cisco NX-OS does not, by default,
redistribute the default route into the RIP routing domain. You can generate a default route into RIP,
which can be controlled by a route policy.
You also configure the default metric that is used for all imported routes into RIP.
OL-20002-02
RIP with Split Horizon Poison Reverse
Chapter 16, "Configuring Route Policy Manager."
Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
Information About RIP
Figure 12-1 shows a sample RIP network with
12-3