BGP FRR configuration example
Network requirements
As shown in Figure 73, configure BGP FRR so that when Link B fails, BGP uses Link A to forward traffic.
Figure 73: Network diagram
Configuration procedure
Configure IP addresses for interfaces. (Details not shown.)
Configure OSPF in AS 200 to ensure connectivity among Switch B, Switch C and Switch D. (Details not shown.)
Configure BGP connections:
# Configure Switch A to establish EBGP sessions with Switch B and Switch C, and advertise network 1.1.1.1/32.
<SwitchA> system-view [SwitchA] bgp 100 [SwitchA-bgp] router-id 1.1.1.1 [SwitchA-bgp] peer 10.1.1.2 as-number 200 [SwitchA-bgp] peer 30.1.1.3 as-number 200 [SwitchA-bgp] address-family ipv4 unicast [SwitchA-bgp-ipv4] peer 10.1.1.2 enable [SwitchA-bgp-ipv4] peer 30.1.1.3 enable [SwitchA-bgp-ipv4] network 1.1.1.1 32
# Configure Switch B to establish an EBGP session with Switch A, and an IBGP session with Switch D.
<SwitchB> system-view [SwitchB] bgp 200 [SwitchB-bgp] router-id 2.2.2.2 [SwitchB-bgp] peer 10.1.1.1 as-number 100 [SwitchB-bgp] peer 4.4.4.4 as-number 200 [SwitchB-bgp] peer 4.4.4.4 connect-interface loopback 0 [SwitchB-bgp] address-family ipv4 unicast [SwitchB-bgp-ipv4] peer 10.1.1.1 enable [SwitchB-bgp-ipv4] peer 4.4.4.4 enable [SwitchB-bgp-ipv4] peer 4.4.4.4 next-hop-local [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit
# Configure Switch C to establish an EBGP session with Switch A, and an IBGP session with Switch D.
<SwitchC> system-view [SwitchC] bgp 200 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 30.1.1.1 as-number 100 [SwitchC-bgp] peer 4.4.4.4 as-number 200 [SwitchC-bgp] peer 4.4.4.4 connect-interface loopback 0 [SwitchC-bgp] address-family ipv4 unicast [SwitchC-bgp-ipv4] peer 30.1.1.1 enable [SwitchC-bgp-ipv4] peer 4.4.4.4 enable [SwitchC-bgp-ipv4] peer 4.4.4.4 next-hop-local [SwitchC-bgp-ipv4] quit [SwitchC-bgp] quit
# Configure Switch D to establish IBGP sessions with Switch B and Switch C, and advertise network 4.4.4.4/32.
<SwitchD> system-view [SwitchD] bgp 200 [SwitchD-bgp] router-id 4.4.4.4 [SwitchD-bgp] peer 2.2.2.2 as-number 200 [SwitchD-bgp] peer 2.2.2.2 connect-interface loopback 0 [SwitchD-bgp] peer 3.3.3.3 as-number 200 [SwitchD-bgp] peer 3.3.3.3 connect-interface loopback 0 [SwitchD-bgp] address-family ipv4 unicast [SwitchD-bgp-ipv4] peer 2.2.2.2 enable [SwitchD-bgp-ipv4] peer 3.3.3.3 enable [SwitchD-bgp-ipv4] network 4.4.4.4 32
Configure preferred values so Link B is used to forward traffic between Switch A and Switch D:
# Configure Switch A to set the preferred value to 100 for routes received from Switch B.
[SwitchA-bgp-ipv4] peer 10.1.1.2 preferred-value 100 [SwitchA-bgp-ipv4] quit [SwitchA-bgp] quit
# Configure Switch D to set the preferred value to 100 for routes received from Switch B.
[SwitchD-bgp-ipv4] peer 2.2.2.2 preferred-value 100 [SwitchD-bgp-ipv4] quit [SwitchD-bgp] quit
Configure BGP FRR:
# On Switch A, configure the source address of BFD echo packets as 11.1.1.1.
[SwitchA] bfd echo-source-ip 11.1.1.1
# Create routing policy frr to set a backup next hop 30.1.1.3 (Switch C) for the route destined for 4.4.4.4/32.
[SwitchA] ip prefix-list abc index 10 permit 4.4.4.4 32 [SwitchA] route-policy frr permit node 10 [SwitchA-route-policy] if-match ip address prefix-list abc [SwitchA-route-policy] apply fast-reroute backup-nexthop 30.1.1.3 [SwitchA-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[SwitchA] bgp 100 [SwitchA-bgp] address-family ipv4 unicast [SwitchA-bgp-ipv4] fast-reroute route-policy frr [SwitchA-bgp-ipv4] quit [SwitchA-bgp] quit
# On Switch D, configure the source address of BFD echo packets as 44.1.1.1.
[SwitchD] bfd echo-source-ip 44.1.1.1
# Create routing policy frr to set a backup next hop 3.3.3.3 (Switch C) for the route destined for 1.1.1.1/32.
[SwitchD] ip prefix-list abc index 10 permit 1.1.1.1 32 [SwitchD] route-policy frr permit node 10 [SwitchD-route-policy] if-match ip address prefix-list abc [SwitchD-route-policy] apply fast-reroute backup-nexthop 3.3.3.3 [SwitchD-route-policy] quit
# Apply the routing policy to BGP FRR for BGP IPv4 unicast address family.
[SwitchD] bgp 200 [SwitchD-bgp] address-family ipv4 unicast [SwitchD-bgp-ipv4] fast-reroute route-policy frr [SwitchD-bgp-ipv4] quit [SwitchD-bgp] quit
Verifying the configuration
# Display detailed information about the route to 4.4.4.4/32 on Switch A. The output shows the backup next hop for the route.
[SwitchA] display ip routing-table 4.4.4.4 32 verbose
Summary Count : 1
Destination: 4.4.4.4/32
Protocol: BGP Process ID: 0
SubProtID: 0x2 Age: 00h01m52s
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 200
NibID: 0x15000003 LastAs: 200
AttrID: 0x5 Neighbor: 10.1.1.2
Flags: 0x10060 OrigNextHop: 10.1.1.2
Label: NULL RealNextHop: 10.1.1.2
BkLabel: NULL BkNextHop: 30.1.1.3
Tunnel ID: Invalid Interface: Vlan-interface 100
BkTunnel ID: Invalid BkInterface: Vlan-interface 200
FtnIndex: 0x0
# Display detailed information about the route to 1.1.1.1/32 on Switch D. The output shows the backup next hop for the route.
[SwitchD] display ip routing-table 1.1.1.1 32 verbose
Summary Count : 1
Destination: 1.1.1.1/32
Protocol: BGP Process ID: 0
SubProtID: 0x1 Age: 00h00m36s
Cost: 0 Preference: 255
IpPre: N/A QosLocalID: N/A
Tag: 0 State: Active Adv
OrigTblID: 0x0 OrigVrf: default-vrf
TableID: 0x2 OrigAs: 100
NibID: 0x15000003 LastAs: 100
AttrID: 0x1 Neighbor: 2.2.2.2
Flags: 0x10060 OrigNextHop: 2.2.2.2
Label: NULL RealNextHop: 20.1.1.2
BkLabel: NULL BkNextHop: 40.1.1.3
Tunnel ID: Invalid Interface: Vlan-interface 101
BkTunnel ID: Invalid BkInterface: Vlan-interface 201
FtnIndex: 0x0