Juniper JUNOSE SOFTWARE FOR E SERIES 11.0.X - BGP AND MPLS CONFIGURATION GUIDE 2009-12-30 Configuration Manual page 147

You can use the neighbor next-hop-self command to correct this routing problem.
If you use this command to configure router Madrid, the third-party next hop
advertised by router Toledo is not advertised to router Barcelona. Instead, router
Madrid advertises 192.168.22.0/23 with the next-hop attribute set to its own IP
address, 10.19.7.7. Router Barcelona now forwards traffic destined for
192.168.22.0/23 to the next hop, 10.19.7.7. Router Madrid then passes the traffic
along to router Toledo.
To disable third-party next-hop processing, configure router Madrid as follows:
neighbor next-hop-self
host1(config)#router bgp 319
host1(config-router)#neighbor 10.19.7.8 remote-as 211
host1(config-router)#neighbor 10.19.7.8 next-hop-self
Use to prevent third-party next hops from being used on NBMA media such as
Frame Relay. This command is useful in nonmeshed networks such as Frame
Relay or where BGP neighbors may not have direct access to the same IP subnet.
Forces the BGP speaker to report itself as the next hop for an advertised route
it learned from a neighbor.
If you specify a BGP peer group by using the peerGroupName argument, all the
members of the peer group inherit the characteristic configured with this
command. You cannot override the characteristic for a specific member of the
peer group.
New policy values are applied to all routes that are sent (outbound policy) or
received (inbound policy) after you issue the command.
To apply the new policy to routes that are already present in the BGP routing
table, you must use the clear ip bgp command to perform a soft clear or hard
clear of the current BGP session.
Behavior is different for outbound policies configured for peer groups for which
you have enabled Adj-RIBs-Out. If you change the outbound policy for such a
peer group and want to fill the Adj-RIBs-Out table for that peer group with the
results of the new policy, you must use the clear ip bgp peer-group command
to perform a hard clear or outbound soft clear of the peer group. You cannot
merely perform a hard clear or outbound soft clear for individual peer group
members because that causes BGP to resend only the contents of the Adj-RIBs-Out
table.
Issuing this command automatically removes the neighbor next-hop-unchanged
configuration (enabled or disabled) on the peer or peer group. Issuing the no or
default version of this command has no effect on the neighbor
next-hop-unchanged configuration.
Use the no version to disable this feature (and therefore enable next-hop
processing of BGP updates). Use the default version to remove the explicit
configuration from the peer or peer group and reestablish inheritance of the
feature configuration.
See neighbor next-hop-self.
Chapter 1: Configuring BGP Routing
Selecting the Best Path
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