Configuring The Next_Hop Attribute - HP MSR Series Configuration Manual

Configuring the NEXT_HOP attribute

By default, when advertising routes to an IBGP peer or peer group, a BGP router does not set itself as the
next hop. However, to ensure a BGP peer can find the correct next hop in some cases, you need to
configure the router as the next hop for routes sent to the peer.
For example, as shown in
Router B and Router C establish an IBGP neighbor relationship. When Router B advertises a network
learned from Router A to Router C, if Router C has no route to IP address 1.1.1.1/24, you need to configure
Router B to set itself as the next hop (3.1.1.1/24) for the route to be sent to Router C.
Figure 59 Next hop attribute configuration
If a BGP router has two peers on a common broadcast network, it does not set itself as the next hop for
routes sent to an EBGP peer by default. As shown in
neighbor relationship, and Router B and Router C establish an IBGP neighbor relationship. They are on
the same broadcast network 1.1.1.0/24. When Router B sends EBGP routes to Router A, it does not set
itself as the next hop by default. However, you can configure Router B to set it as the next hop (1.1.1.2/24)
for routes sent to Router A by using the peer next-hop-local command as needed.
Figure 60 Next hop attribute configuration
IMPORTANT:
If you have configured BGP load balancing, the router sets itself as the next hop for routes sent to an IBGP
peer or peer group regardless of whether the peer next-hop-local command is configured.
To configure the NEXT_HOP attribute:
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN
instance view.
Figure 59, Router A and Router B establish an EBGP neighbor relationship, and
Command
system-view
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
197
Figure 60, Router A and Router B establish an EBGP
Remarks
N/A
Use either method.