Ein interessantes Feature ist BGP unnumbered. Hier muss nicht mehr jeder Nachber per IP-Adresse und AS-Nummer angegeben werden, sondern nur noch das Interface, an dem der BGP-Nachbar erwartet wird.
Der Beitrag “EVPN unter Cumulus” dient hier als Beispiel. Die BGP Konfiguration wird von “klassisch” auf “unnumberd” umgestellt.
Folgende Topologie wird verwendet:
Die Anpassung der Konfiguration ist recht schnell erledigt, der Bereich L2VPN wird automatisch angepasst.
Leaf01
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net add bgp bestpath as-path multipath-relax
net del bgp neighbor 10.23.0.1 remote-as 65100
net del bgp neighbor 10.23.0.9 remote-as 65100
net add bgp neighbor swp1 interface remote-as external
net add bgp neighbor swp2 interface remote-as external
net commit
Leaf02
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net add bgp bestpath as-path multipath-relax
net del bgp neighbor 10.23.0.5 remote-as 65100
net del bgp neighbor 10.23.0.13 remote-as 65100
net add bgp neighbor swp1 interface remote-as external
net add bgp neighbor swp2 interface remote-as external
net commit
Spine01
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net add bgp bestpath as-path multipath-relax
net del bgp neighbor 10.23.0.2 remote-as 65001
net del bgp neighbor 10.23.0.6 remote-as 65002
net add bgp neighbor swp1 interface remote-as external
net add bgp neighbor swp2 interface remote-as external
net commit
Spine02
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net add bgp bestpath as-path multipath-relax
net del bgp neighbor 10.23.0.10 remote-as 65001
net del bgp neighbor 10.23.0.14 remote-as 65002
net add bgp neighbor swp1 interface remote-as external
net add bgp neighbor swp2 interface remote-as external
net commit
Damit ist BGP unnumbered aktiv.
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cumulus@spine02:mgmt-vrf:~$ net sh bgp summary
show bgp ipv4 unicast summary
=============================
BGP router identifier 172.16.1.2, local AS number 65100 vrf-id 0
BGP table version 68
RIB entries 15, using 2280 bytes of memory
Peers 2, using 39 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
leaf01(swp1) 4 65001 24 22 0 0 0 00:00:26 4
leaf02(swp2) 4 65002 26 21 0 0 0 00:00:26 4
Total number of neighbors 2
show bgp ipv6 unicast summary
=============================
% No BGP neighbors found
show bgp l2vpn evpn summary
===========================
BGP router identifier 172.16.1.2, local AS number 65100 vrf-id 0
BGP table version 0
RIB entries 3, using 456 bytes of memory
Peers 2, using 39 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
leaf01(swp1) 4 65001 24 22 0 0 0 00:00:26 3
leaf02(swp2) 4 65002 26 21 0 0 0 00:00:26 4
Total number of neighbors 2
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cumulus@spine02:mgmt-vrf:~$ net sh 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, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
F - PBR,
> - selected route, * - FIB route
B>* 10.10.10.0/24 [20/0] via 10.23.0.14, swp2, 00:06:18
* via 10.23.0.10, swp1, 00:06:18
B>* 10.23.0.0/30 [20/0] via 10.23.0.10, swp1, 00:06:18
B>* 10.23.0.4/30 [20/0] via 10.23.0.14, swp2, 00:06:18
B 10.23.0.8/30 [20/0] via 10.23.0.10 inactive, 00:06:18
B 10.23.0.12/30 [20/0] via 10.23.0.14 inactive, 00:06:18
B>* 172.16.0.1/32 [20/0] via 10.23.0.10, swp1, 00:06:18
B>* 172.16.0.2/32 [20/0] via 10.23.0.14, swp2, 00:06:18
Beide Clients sind in der Lage sich zu pingen.
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server01:~# ping 10.10.10.3 -c 3
PING 10.10.10.3 (10.10.10.3): 56 data bytes
64 bytes from 10.10.10.3: seq=0 ttl=64 time=1.641 ms
64 bytes from 10.10.10.3: seq=1 ttl=64 time=1.394 ms
64 bytes from 10.10.10.3: seq=2 ttl=64 time=1.372 ms
server02:~# ping 10.10.10.2 -c 3
PING 10.10.10.2 (10.10.10.2): 56 data bytes
64 bytes from 10.10.10.2: seq=0 ttl=64 time=1.581 ms
64 bytes from 10.10.10.2: seq=1 ttl=64 time=3.922 ms
64 bytes from 10.10.10.2: seq=2 ttl=64 time=2.610 ms