Configuring The Next_Hop Attribute - HPE FlexNetwork HSR6800 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
relationship, and 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 70 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
an EBGP 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 71 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
Enter system view.
1.
Enter BGP view or
2.
BGP-VPN instance view.
Figure 70, Router A and Router B establish an EBGP neighbor
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
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Figure 71, Router A and Router B establish
Remarks
N/A
Use either method.