admin@nba610-1:~$ vtysh
Hello, this is FRRouting (version 7.5.1-sonic).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
nba610-1# configure
nba610-1(config)# router bgp 65101
nba610-1(config-router)# bgp router-id 10.10.10.1
nba610-1(config-router)# no bgp ebgp-requires-policy
nba610-1(config-router)# neighbor Ethernet69 interface remote-as 65200
nba610-1(config-router)# address-family ipv6 unicast
nba610-1(config-router-af)# neighbor Ethernet69 activate
nba610-1(config-router-af)# end
nba610-1# write
BGP Unnumbered in SONiC
Example model & SONiC version:
- Aurora 610
- Netberg SONiC: SONiC.202111-nba610-support.0
A standard BGP requires the user to configure explicit BGP sessions with the neighbor IP address and remote-AS information for each BGP peer to exchange IPv4 prefixes, which can consume a significant amount of IP addresses in large networks.
Instead of specifying an IPv4 neighbor address, the user can provide the L3 port number and remote-AS number to declare an eBGP session. BGP unnumbered uses the IPv6 link-local address as the next-hop IP address for both IPv4 and IPv6 prefixes.
Limitations:
- BGP unnumbered supports:
- L2 interface that is not part of a Port-Channel or a VLAN.
- Layer 3 interfaces on port, port-channel, and VLAN interfaces.
Please refer to the HLD for more details.
SONiC 202111 or later supports the “link-local-only” setting for using with BGP unnumbered.
Example:
admin@nba610-1:~$ sudo config interface ipv6 enable use-link-local-only Ethernet69 admin@nba610-1:~$ show ipv6 link-local-mode +------------------+----------+ | Interface Name | Mode | +==================+==========+ | Ethernet69 | Enabled | +------------------+----------+ | Ethernet73 | Disabled | +------------------+----------+
BGP unnumbered configuration
Figure 1. Network topology
- Configure Loopback0 following the topology.
- Configure BGP in FRRouting
Aurora 610-1
Aurora 610-2
admin@nba610-2:~$ vtysh Hello, this is FRRouting (version 7.5.1-sonic). Copyright 1996-2005 Kunihiro Ishiguro, et al. nba610-2# configure nba610-2(config)# router bgp 65200 nba610-2(config-router)# bgp router-id 10.10.10.100 nba610-2(config-router)# no bgp ebgp-requires-policy nba610-2(config-router)# neighbor Ethernet68 interface remote-as 65101 nba610-2(config-router)# address-family ipv6 unicast nba610-2(config-router-af)# neighbor Ethernet68 activate nba610-2(config-router-af)# end nba610-2# write - Check the BGP status
Aurora 610-1
nba610-1# show bgp summary
IPv4 Unicast Summary:
BGP router identifier 10.10.10.1, local AS number 65101 vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt
Ethernet69 4 65200 13 20 0 0 0 00:00:07 0 0
Total number of neighbors 1
IPv6 Unicast Summary:
BGP router identifier 10.10.10.1, local AS number 65101 vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt
Ethernet69 4 65200 13 20 0 0 0 00:00:07 0 0
Total number of neighbors 1
nba610-1# show bgp neighbors
BGP neighbor on Ethernet69: fe80::3a68:ddff:fe52:236c, remote AS 65200, local AS 65101, external link
Hostname: sonic
BGP version 4, remote router ID 10.10.10.100, local router ID 10.10.10.1
BGP state = Established, up for 00:03:44
Last read 00:00:44, Last write 00:00:44
Hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
4 Byte AS: 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)
Address Family IPv4 Unicast: advertised and received
Address Family IPv6 Unicast: advertised and received
Hostname Capability: advertised (name: sonic,domain name: n/a) received (name: sonic,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: Yes
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: 7 6
Notifications: 8 2
Updates: 3 3
Keepalives: 5 5
Route Refresh: 0 0
Capability: 0 0
Total: 23 16
Minimum time between advertisement runs is 0 seconds
For address family: IPv4 Unicast
Update group 7, subgroup 7
Packet Queue length 0
Community attribute sent to this neighbor(all)
0 accepted prefixes
For address family: IPv6 Unicast
Update group 8, subgroup 8
Packet Queue length 0
Community attribute sent to this neighbor(all)
0 accepted prefixes
Connections established 2; dropped 1
Last reset 00:03:46, No AFI/SAFI activated for peer
Message received that caused BGP to send a NOTIFICATION:
FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF
00640104 00C800B4 0A0A0A65 47020601
04000100 01020805 06000100 01000202
06010400 02000102 02800002 02020002
06410400 0000C802 0A450800 01010100
02010102 09490705 736F6E69 63000204
40020078
Local host: fe80::3a68:ddff:fe52:23bc, Local port: 179
Foreign host: fe80::3a68:ddff:fe52:236c, Foreign port: 52466
Nexthop: 10.10.10.1
Nexthop global: fe80::3a68:ddff:fe52:23bc
Nexthop local: fe80::3a68:ddff:fe52:23bc
BGP connection: shared network
BGP Connect Retry Timer in Seconds: 120
Read thread: on Write thread: on FD used: 28Aurora 610-2
nba610-2# show bgp summary
IPv4 Unicast Summary:
BGP router identifier 10.10.10.100, local AS number 65200 vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt
Ethernet68 4 65101 7 9 0 0 0 00:00:01 0 0
Total number of neighbors 1
IPv6 Unicast Summary:
BGP router identifier 10.10.10.100, local AS number 65200 vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt
Ethernet68 4 65101 7 9 0 0 0 00:00:01 0 0
Total number of neighbors 1
nba610-2# show bgp neighbors
BGP neighbor on Ethernet68: fe80::3a68:ddff:fe52:23bc, remote AS 65101, local AS 65200, external link
Hostname: sonic
BGP version 4, remote router ID 10.10.10.1, local router ID 10.10.10.100
BGP state = Established, up for 00:06:10
Last read 00:00:10, Last write 00:00:10
Hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
4 Byte AS: 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)
Address Family IPv4 Unicast: advertised and received
Address Family IPv6 Unicast: advertised and received
Hostname Capability: advertised (name: sonic,domain name: n/a) received (name: sonic,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: Yes
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: 2 2
Notifications: 2 0
Updates: 3 3
Keepalives: 8 8
Route Refresh: 0 0
Capability: 0 0
Total: 15 13
Minimum time between advertisement runs is 0 seconds
For address family: IPv4 Unicast
Update group 7, subgroup 7
Packet Queue length 0
Community attribute sent to this neighbor(all)
0 accepted prefixes
For address family: IPv6 Unicast
Update group 8, subgroup 8
Packet Queue length 0
Community attribute sent to this neighbor(all)
0 accepted prefixes
Connections established 2; dropped 1
Last reset 00:06:12, Notification sent (Cease/Other Configuration Change)
Local host: fe80::3a68:ddff:fe52:236c, Local port: 52466
Foreign host: fe80::3a68:ddff:fe52:23bc, Foreign port: 179
Nexthop: 10.10.10.100
Nexthop global: fe80::3a68:ddff:fe52:236c
Nexthop local: fe80::3a68:ddff:fe52:236c
BGP connection: shared network
BGP Connect Retry Timer in Seconds: 120
Estimated round trip time: 5 ms
Read thread: on Write thread: on FD used: 27