Modifying redistribution parameters, Enabling recursive next-hop lookups – Brocade BigIron RX Series Configuration Guide User Manual

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BigIron RX Series Configuration Guide

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Modifying redistribution parameters

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The next-hop IP address for 102.0.0.1 is not an IGP route, which means the BGP route’s destination
still cannot be reached through IP. The recursive next-hop lookup feature performs a lookup on
10.0.0.1’s next-hop gateway:

This lookup results in an IGP route. In fact, this route is a directly-connected route. As a result, the
BGP route’s destination is now reachable through IGP, which means the BGP route is eligible for
installation in the IP route table. Here is the BGP route in the IP route table.

This BigIron RX can use this route because the device has an IP route to the next-hop gateway.
Without recursive next-hop lookups, this route would not be in the IP route table.

Enabling recursive next-hop lookups

The recursive next-hop lookups feature is disabled by default.

To enable recursive next-hop lookups, enter the following command at the BGP configuration level
of the CLI.

BigIron RX(config-bgp)# next-hop-recursion

Syntax: [no] next-hop-recursion

Modifying redistribution parameters

By default, the router does not redistribute route information between BGP4 and the IP IGPs (RIP,
ISIS, and OSPF). You can configure the router to redistribute OSPF, ISIS, or RIP routes, directly
connected routes, or static routes into BGP4.

To enable redistribution of all OSPF routes and directly attached routes into BGP4, enter the
following commands.

BigIron RX(config)# router bgp

BigIron RX(config-bgp)# redistribute ospf

BigIron RX(config-bgp)# redistribute connected

BigIron RX(config-bgp)# write memory

Syntax: [no] redistribute connected | ospf | rip | isis | static

The connected parameter indicates that you are redistributing routes to directly attached devices
into BGP.

The ospf parameter indicates that you are redistributing OSPF routes into BGP4.

BigIron RX# show ip route 10.0.0.1

Total number of IP routes: 38

Network Address Gateway Port Cost Type

10.0.0.0 0.0.0.0 1/1 1 D

AS_PATH: 65001 4355 1

BigIron RX# show ip route 240.0.0.0/24

Total number of IP routes: 38

Network Address Gateway Port Cost Type

240.0.0.0 10.0.0.1 1/1 1 B

AS_PATH: 65001 4355 1

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