BGP route summarization configuration example
Network requirements
As shown in Figure 61, run EBGP between Switch C and Switch D, so the internal network and external network can communicate with each other.
In AS 65106, configure static routing between Switch A and Switch B, configure OSPF between Switch B and Switch C, and configure OSPF to redistribute static routes, so the devices in the internal network can communicate with each other.
Configure route summarization on Switch C so BGP advertises a summary route instead of the specific networks 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 to Switch D.
Figure 61: Network diagram
Configuration procedure
Configure IP addresses for interfaces. (Details not shown.)
Configure static routing between Switch A and Switch B:
# Configure a default route with the next hop 192.168.212.1 on Switch A.
<SwitchA> system-view [SwitchA] ip route-static 0.0.0.0 0 192.168.212.1
# Configure static routes to 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 with the same next hop 192.168.212.161 on Switch B.
<SwitchB> system-view [SwitchB] ip route-static 192.168.64.0 24 192.168.212.161 [SwitchB] ip route-static 192.168.74.0 24 192.168.212.161 [SwitchB] ip route-static 192.168.99.0 24 192.168.212.161
Configure OSPF between Switch B and Switch C and configure OSPF on Switch B to redistribute static routes:
# Configure OSPF to advertise the local network and enable OSPF to redistribute static routes on Switch B.
[SwitchB] ospf [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] quit [SwitchB-ospf-1] import-route static [SwitchB-ospf-1] quit
# Configure OSPF to advertise the local networks on Switch C.
[SwitchC] ospf [SwitchC-ospf-1] area 0 [SwitchC-ospf-1-area-0.0.0.0] network 172.17.100.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] network 10.220.2.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] quit [SwitchC-ospf-1] quit
# Display the IP routing table on Switch C.
[SwitchC] display ip routing-table protocol ospf Summary Count : 5 OSPF Routing table Status : <Active> Summary Count : 3 Destination/Mask Proto Pre Cost NextHop Interface 192.168.64.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.74.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.99.0/24 OSPF 150 1 172.17.100.1 Vlan100 OSPF Routing table Status : <Inactive> Summary Count : 2 Destination/Mask Proto Pre Cost NextHop Interface 10.220.2.0/24 OSPF 10 1 10.220.2.16 Vlan200 172.17.100.0/24 OSPF 10 1 172.17.100.2 Vlan100
The output shows that Switch C has learned routes to 192.168.64.0/24, 192.168.99.0/24, and 192.168.64.0/18 through OSPF.
Configure BGP between Switch C and Switch D and configure BGP on Switch C to redistribute OSPF routes:
# On Switch C, enable BGP, specify Switch D as an EBGP peer, and configure BGP to redistribute OSPF routes.
[SwitchC] bgp 65106 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 10.220.2.217 as-number 64631 [SwitchC-bgp] address-family ipv4 unicast [SwitchC-bgp-ipv4] peer 10.220.2.217 enable [SwitchC-bgp-ipv4] import-route ospf
# Enable BGP, and configure Switch C as an EBGP peer on Switch D.
[SwitchD] bgp 64631 [SwitchD-bgp] router-id 4.4.4.4 [SwitchD-bgp] peer 10.220.2.16 as-number 65106 [SwitchD-bgp] address-family ipv4 unicast [SwitchD-bgp-ipv4] peer 10.220.2.16 enable [SwitchD-bgp-ipv4] quit [SwitchD-bgp] quit
# Display the IP routing table on Switch D.
[SwitchD] display ip routing-table protocol bgp Summary Count : 3 BGP Routing table Status : <Active> Summary Count : 3 Destination/Mask Proto Pre Cost NextHop Interface 192.168.64.0/24 BGP 255 1 10.220.2.16 Vlan200 192.168.74.0/24 BGP 255 1 10.220.2.16 Vlan200 192.168.99.0/24 BGP 255 1 10.220.2.16 Vlan200 BGP Routing table Status : <Inactive> Summary Count : 0
The output shows that Switch D has learned routes to 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 through BGP.
After the above configurations, ping hosts on networks 192.168.74.0/24, 192.168.99.0/24, and 192.168.64.0/18 from Switch D. The ping operations succeed.
Configure route summarization on Switch C to summarize 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 into a single route 192.168.64.0/18 on Switch C, and disable advertisement of the specific routes.
[SwitchC-bgp-ipv4] aggregate 192.168.64.0 18 detail-suppressed [SwitchC-bgp-ipv4] quit [SwitchC-bgp] quit
Verifying the configuration
# Display IP routing table on Switch C.
[SwitchC] display ip routing-table | include 192.168 192.168.64.0/18 BGP 130 0 127.0.0.1 NULL0 192.168.64.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.74.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.99.0/24 OSPF 150 1 172.17.100.1 Vlan100
The output shows that Switch C has a summary route 192.168.64.0/18 with the output interface Null0.
# Display IP routing table on Switch D.
[SwitchD] display ip routing-table protocol bgp Summary Count : 1 BGP Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface 192.168.64.0/18 BGP 255 0 10.220.2.16 Vlan200 BGP Routing table Status : <Inactive> Summary Count : 0
The output shows that Switch D has only one route 192.168.64.0/18 to AS 65106.
After the above configurations, ping the hosts on networks 192.168.64.0/24, 192.168.74.0/24 and 192.168.99.0/24 from Switch D. The ping operations succeed.