Frr: BGPd: confederation peers not considered internal

Created on 14 Jun 2020 · 6Comments · Source: FRRouting/frr

Issue

_Description:_ BGP confederation peer(s) not considered internal, if neighbour Autonomous System Number is different from local Autonomous System Number.

Logs

ansible@debian:~$ vtysh -f /etc/frr/frr.conf

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 256: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.4 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 262: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:910d:5bf3:55f5:db63 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 269: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.5 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 275: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:f335:a16f:74d6:e533 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 282: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.6 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 288: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:289a:f4a4:94ea:712b peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 295: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.7 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 301: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:a0c:fae4:46d3:5c32 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 308: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.8 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 314: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:d76b:3002:c67:71cc peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 321: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.9 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 327: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:71f0:e3dd:371:a15d peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 334: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.10 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 340: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:c8d3:b45b:3782:73f9 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 347: Failure to communicate[13] to bgpd, line:  neighbor 172.20.230.11 peer-group ibgppeer

% Peer with AS 4294000840 cannot be in this peer-group, members must be all internal or all external
line 353: Failure to communicate[13] to bgpd, line:  neighbor fd00:aaaa:251:0:b698:5e53:5366:b81b peer-group ibgppeer

Configuration except Autonomous System Numbers used in the set-up

router bgp 4294000840
 bgp confederation identifier 4242420144
 bgp confederation peers 4294000100 4294000276 4294000528 4294000826 4294000756 4294000036 4294000702
 !
 neighbor ibgppeer peer-group
 neighbor ibgppeer advertisement-interval 5
 neighbor ibgppeer bfd check-control-plane-failure
 neighbor ibgppeer capability dynamic
 neighbor ibgppeer capability extended-nexthop
 neighbor ibgppeer description IBGP PEER
 neighbor ibgppeer disable-connected-check
 neighbor ibgppeer solo
 neighbor ibgppeer strict-capability-match
 neighbor ibgppeer timers 100 300
 neighbor ibgppeer timers connect 120
 neighbor ibgppeer ttl-security hops 15
 !
 neighbor 172.20.230.0 remote-as 4294000276
 neighbor 172.20.230.0 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:fb36:3896:e4ba:8fea remote-as 4294000276
 neighbor fd00:aaaa:251:0:fb36:3896:e4ba:8fea peer-group ibgppeer
 neighbor 172.20.230.1 remote-as 4294000100
 neighbor 172.20.230.1 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:da0d:40fb:158:c22e remote-as 4294000100
 neighbor fd00:aaaa:251:0:da0d:40fb:158:c22e peer-group ibgppeer
 neighbor 172.20.230.2 remote-as 4294000826
 neighbor 172.20.230.2 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:28d2:cfd1:824d:d308 remote-as 4294000826
 neighbor fd00:aaaa:251:0:28d2:cfd1:824d:d308 peer-group ibgppeer
 neighbor 172.20.230.3 remote-as 4294000528
 neighbor 172.20.230.3 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:d28a:fdc1:2c28:9c1e remote-as 4294000528
 neighbor fd00:aaaa:251:0:d28a:fdc1:2c28:9c1e peer-group ibgppeer
 neighbor 172.20.230.4 remote-as 4294000840
 neighbor 172.20.230.4 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:910d:5bf3:55f5:db63 remote-as 4294000840
 neighbor fd00:aaaa:251:0:910d:5bf3:55f5:db63 peer-group ibgppeer
 neighbor 172.20.230.5 remote-as 4294000840
 neighbor 172.20.230.5 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:f335:a16f:74d6:e533 remote-as 4294000840
 neighbor fd00:aaaa:251:0:f335:a16f:74d6:e533 peer-group ibgppeer
 neighbor 172.20.230.6 remote-as 4294000840
 neighbor 172.20.230.6 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:289a:f4a4:94ea:712b remote-as 4294000840
 neighbor fd00:aaaa:251:0:289a:f4a4:94ea:712b peer-group ibgppeer
 neighbor 172.20.230.7 remote-as 4294000840
 neighbor 172.20.230.7 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:a0c:fae4:46d3:5c32 remote-as 4294000840
 neighbor fd00:aaaa:251:0:a0c:fae4:46d3:5c32 peer-group ibgppeer
 neighbor 172.20.230.8 remote-as 4294000840
 neighbor 172.20.230.8 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:d76b:3002:c67:71cc remote-as 4294000840
 neighbor fd00:aaaa:251:0:d76b:3002:c67:71cc peer-group ibgppeer
 neighbor 172.20.230.9 remote-as 4294000840
 neighbor 172.20.230.9 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:71f0:e3dd:371:a15d remote-as 4294000840
 neighbor fd00:aaaa:251:0:71f0:e3dd:371:a15d peer-group ibgppeer
 neighbor 172.20.230.10 remote-as 4294000840
 neighbor 172.20.230.10 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:c8d3:b45b:3782:73f9 remote-as 4294000840
 neighbor fd00:aaaa:251:0:c8d3:b45b:3782:73f9 peer-group ibgppeer
 neighbor 172.20.230.11 remote-as 4294000840
 neighbor 172.20.230.11 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:b698:5e53:5366:b81b remote-as 4294000840
 neighbor fd00:aaaa:251:0:b698:5e53:5366:b81b peer-group ibgppeer
 neighbor 172.20.230.13 remote-as 4294000276
 neighbor 172.20.230.13 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:fabd:db4c:693f:758f remote-as 4294000276
 neighbor fd00:aaaa:251:0:fabd:db4c:693f:758f peer-group ibgppeer
 neighbor 172.20.230.14 remote-as 4294000756
 neighbor 172.20.230.14 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:4cd5:3054:b7d0:5173 remote-as 4294000756
 neighbor fd00:aaaa:251:0:4cd5:3054:b7d0:5173 peer-group ibgppeer
 neighbor 172.20.230.15 remote-as 4294000036
 neighbor 172.20.230.15 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:e76d:64af:ef5f:7b5b remote-as 4294000036
 neighbor fd00:aaaa:251:0:e76d:64af:ef5f:7b5b peer-group ibgppeer
 neighbor 172.20.230.16 remote-as 4294000702
 neighbor 172.20.230.16 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:dfb2:fa69:9984:1e50 remote-as 4294000702
 neighbor fd00:aaaa:251:0:dfb2:fa69:9984:1e50 peer-group ibgppeer
 neighbor 172.20.230.17 remote-as 4294000276
 neighbor 172.20.230.17 peer-group ibgppeer
 neighbor fd00:aaaa:251:0:7d58:ea76:24f:94f4 remote-as 4294000276
 neighbor fd00:aaaa:251:0:7d58:ea76:24f:94f4 peer-group ibgppeer

Software

FRRouting v7.3.1-1 (from Debian unstable repository)
Debian: 10 (stable) 64bit

ansible@debian:~$ dpkg -l | grep FRRouting
ii  frr                            7.3.1-1                      amd64        FRRouting suite of internet protocols (BGP, OSPF, IS-IS, ...)
ii  frr-doc                        7.3.1-1                      all          FRRouting suite - user manual
ii  frr-pythontools                7.3.1-1                      all          FRRouting suite - Python tools
ii  frr-rpki-rtrlib                7.3.1-1                      amd64        FRRouting suite - BGP RPKI support (rtrlib)
ii  frr-snmp                       7.3.1-1                      amd64        FRRouting suite - SNMP support

Footnotes

The issue may be closed if the coding effort for the change is not considered worth the effort. The GitHub issue is primarily filed to serve as (un-)official documentation of the issue existing.
BGP confed's are deployed by a select large T2 and T1's in our current age.

RFC's on the topic

bgp question

Source

netravnen

All 6 comments

Well, this is as expected. I see Cisco behaves the same.

ton31337 on 17 Jun 2020

@polychaeta autoclose in 1 week.

ton31337 on 17 Jun 2020

👍1

@ton31337 now, being vendor agnostic and w/o compare with other products. What you think about this behavior? I consider that confed should be tracted as IBGP - in fact it's implemented normally to avoid RR or fullmesh.

If we are comparing FRR with other routing daemons let's choose more than one, at least three: IOS-XR, JunOS and SR-OS (to have "quorum" on decisions :stuck_out_tongue_closed_eyes:)

Thanks for your time @ton31337.