Example for Configuring Basic BGP Unnumbered
Networking Requirements
Figure 1. BGP Unnumbered Configuration Example
As shown in Figure 1, Switch A and Switch B are BGP peers. An EBGP connection is established between Switch A and Switch B. To save IP addresses, BGP unnumbered can be configured between Switch A and Switch B. In this example, routed interfaces are configured for the use of BGP unnumbered interface.
The only difference between a BGP unnumbered configuration and the BGP numbered configuration is that the BGP neighbor is specified as an interface instead of an IP address. The interface between the two peers does not need to have an IP address configured on each side.
NOTE: The ebgp-requires-policy function needs to be disabled in EBGP, no need in IBGP. |
Procedure
Switch A
Step 1 Enable te-1/1/1 as a routed interface and configure the interface name as rif-1.
admin@SwitchA# set interface gigabit-ethernet te-1/1/1 routed-interface enable true admin@SwitchA# set interface gigabit-ethernet te-1/1/1 routed-interface name rif-1 admin@SwitchA# set vlans reserved-vlan 80-90 admin@SwitchA# set l3-interface routed-interface rif-1
Step 2 Configure EBGP and disable ebgp-requires-policy policy.
admin@SwitchA# set protocols bgp local-as 65001 admin@SwitchA# set protocols bgp router-id 49.49.49.49 admin@SwitchA# set protocols bgp interface rif-1 remote-as 65002 admin@SwitchA# set protocols bgp interface rif-1 ipv6-unicast activate true admin@SwitchA# set protocols bgp interface rif-1 capability extended-nexthop admin@SwitchA# set protocols bgp ebgp-requires-policy false
Step 3 Enable IP routing.
admin@SwitchA# set ip routing enable true
Step 4 Advertise the host subnets through BGP.
admin@SwitchA# set protocols bgp ipv4-unicast network 49.49.49.49/32
Step 5 Commit the configuration.
admin@SwitchA# commit
Switch B
Step 1 Enable ge-1/1/5 as a routed interface and configure interface name as rif-1.
admin@SwitchB# set interface gigabit-ethernet ge-1/1/5 routed-interface enable true admin@SwitchB# set interface gigabit-ethernet ge-1/1/5 routed-interface name rif-1 admin@SwitchB# set vlans reserved-vlan 80-90 admin@SwitchB# set l3-interface routed-interface rif-1
Step 2 Configure EBGP and disable ebgp-requires-policy policy.
admin@SwitchB# set protocols bgp local-as 65002 admin@SwitchB# set protocols bgp router-id 45.45.45.45 admin@SwitchB# set protocols bgp interface rif-1 remote-as 65001 admin@SwitchB# set protocols bgp interface rif-1 ipv6-unicast activate true admin@SwitchB# set protocols bgp interface rif-1 capability extended-nexthop admin@SwitchB# set protocols bgp ebgp-requires-policy false
Step 3 Enable IP routing.
admin@SwitchB# set ip routing enable true
Step 4 Advertise the host subnets through BGP.
admin@SwitchB# set protocols bgp ipv4-unicast network 45.45.45.45/32
Step 5 Commit the configuration.
admin@SwitchB# commit
Verify the Configuration
- Check the BGP neighbor by running the following command.
admin@SwitchA# run show bgp neighbor BGP neighbor on rif-1: fe80::1a5a:5810:83c:42a1, remote AS 65002, local AS 65001, external link Hostname: SwitchB BGP version 4, remote router ID 45.45.45.45, local router ID 49.49.49.49 BGP state = Established, up for 00:03:38 Last read 00:00:38, Last write 00:00:38 Hold time is 180, keepalive interval is 60 seconds Neighbor capabilities: 4 Byte AS: advertised and received Extended Message: advertised and received AddPath: IPv4 Unicast: RX advertised IPv4 Unicast and received IPv6 Unicast: RX advertised IPv6 Unicast and received Extended nexthop: advertised and received Address families by peer: IPv4 Unicast Route refresh: advertised and received(old & new) Enhanced Route Refresh: advertised and received Address Family IPv4 Unicast: advertised and received Address Family IPv6 Unicast: advertised and received Hostname Capability: advertised (name: 49sw,domain name: n/a) received (name: 45sw,domain name: n/a) Graceful Restart Capability: advertised and received Remote Restart timer is 120 seconds Address families by peer: none Graceful restart information: End-of-RIB send: IPv4 Unicast, IPv6 Unicast End-of-RIB received: IPv4 Unicast, IPv6 Unicast Local GR Mode: Helper* Remote GR Mode: Helper R bit: True Timers: Configured Restart Time(sec): 120 Received Restart Time(sec): 120 IPv4 Unicast: F bit: False End-of-RIB sent: Yes End-of-RIB sent after update: No End-of-RIB received: Yes Timers: Configured Stale Path Time(sec): 360 IPv6 Unicast: F bit: False End-of-RIB sent: Yes End-of-RIB sent after update: Yes End-of-RIB received: Yes Timers: Configured Stale Path Time(sec): 360 Message statistics: Inq depth is 0 Outq depth is 0 Sent Rcvd Opens: 3 2 Notifications: 0 2 Updates: 9 9 Keepalives: 5 5 Route Refresh: 0 0 Capability: 0 0 Total: 17 18 Minimum time between advertisement runs is 0 seconds For address family: IPv4 Unicast Update group 5, subgroup 5 Packet Queue length 0 Community attribute sent to this neighbor(all) 1 accepted prefixes For address family: IPv6 Unicast Update group 6, subgroup 6 Packet Queue length 0 Community attribute sent to this neighbor(all) 0 accepted prefixes Connections established 1; dropped 0 Last reset 00:03:41, No AFI/SAFI activated for peer Local host: fe80::1a5a:5820:61f:63a1, Local port: 179 Foreign host: fe80::1a5a:5810:83c:42a1, Foreign port: 57988 Nexthop local: fe80::1a5a:5820:61f:63a1 BGP connection: shared network BGP Connect Retry Timer in Seconds: 120 Estimated round trip time: 2 ms Read thread: on Write thread: on FD used: 25
- After completing the configuration, check BGP route on the switches.
admin@SwitchA# run show route bgp RIB entry for bgp ================= Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP, T - Table, A - Babel, F - PBR, f - OpenFabric, > - selected route, * - FIB route, q - queued, r - rejected, b - backup t - trapped, o - offload failure B>* 45.45.45.45/32 [20/0] via fe80::1a5a:5810:83c:42a1, rif-1, weight 1, 02:03:58
- Show the brief information for BGP.
admin@SwitchA# run show bgp show bgp ipv4 unicast ===================== BGP table version is 10, local router ID is 49.49.49.49, vrf id 0 Default local pref 100, local AS 65001 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 45.45.45.45/32 rif-1 0 0 65002 i Displayed 1 routes and 1 total paths show bgp ipv6 unicast ===================== No BGP prefixes displayed, 0 exist
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