Re: bgpd loadbalancing feature

On Sat, Aug 13, 2022 at 08:27:53AM +0200, Holger Glaess wrote:
> hi
>
>
> i need a little bit help to understand how i can check if
>
> the new openbgpd do the loadbalancing
>
>
> wendehals# bgpctl sh nei 172.16.2.251
> BGP neighbor is 172.16.2.251, remote AS 65010
>   BGP version 4, remote router-id 172.16.2.251
>   BGP state = Established, up for 00:14:33
>   Last read 00:00:03, holdtime 90s, keepalive interval 30s
>   Last write 00:00:03
>   Neighbor capabilities:
>     Multiprotocol extensions: IPv4 unicast, IPv4 vpn
>     4-byte AS numbers
>     Route Refresh
>     Graceful Restart
>     Add-path: IPv4 unicast bidir, IPv4 vpn bidir
>   Negotiated capabilities:
>     Multiprotocol extensions: IPv4 unicast, IPv4 vpn
>     4-byte AS numbers
>     Route Refresh
>     Graceful Restart
>     Add-path: IPv4 unicast bidir, IPv4 vpn bidir
>
>   Message statistics:
>                   Sent       Received
>   Opens                    3          3
>   Notifications            0          2
>   Updates                 26         25
>   Keepalives              98         98
>   Route Refresh            0          0
>   Total                  127        128
>
>   Update statistics:
>                   Sent       Received
>   Prefixes                 9          9
>   Updates                  9          9
>   Withdraws                0          0
>   End-of-Rib               2          2
>   Route Refresh statistics:
>   Request                  0          0
>   Begin-of-RR              0          0
>   End-of-RR                0          0
>
>   Last received shutdown reason: "bgpd shutting down"
>   Local host:          172.16.2.252, Local port:    179
>   Remote host:         172.16.2.251, Remote port: 48848
>
>
> mean the bidir flag my neibgbor have loadbalancing configured and active ?
>
>
> wendehals# bgpctl sh rib
> flags: * = Valid, > = Selected, I = via IBGP, A = Announced,
>        S = Stale, E = Error
> origin validation state: N = not-found, V = valid, ! = invalid
> origin: i = IGP, e = EGP, ? = Incomplete
>
> flags ovs destination          gateway          lpref   med aspath origin
> *>      N 172.16.1.1/32        172.16.12.5       100     0 65100 i
> *m      N 172.16.1.1/32        172.16.13.1       100     1 65101 i
> I*      N 172.16.1.1/32        172.16.13.5       100     1 65101 i
> I*      N 172.16.1.1/32        172.16.12.1       100     0 65100 i
> *>      N 172.16.1.2/32        172.16.12.5       100     1 65100 i
> *m      N 172.16.1.2/32        172.16.13.1       100     0 65101 i
> I*      N 172.16.1.2/32        172.16.13.5       100     0 65101 i
> I*      N 172.16.1.2/32        172.16.12.1       100     1 65100 i
> I*>     N 172.16.2.251/32      172.16.2.251      100     0 i
> *       N 172.16.2.251/32      172.16.12.5       100    11 65100 i
> *       N 172.16.2.251/32      172.16.13.1       100    11 65101 i
> I*      N 172.16.2.251/32      172.16.12.2       100    11 65100 i
> I*      N 172.16.2.251/32      172.16.13.6       100    11 65101 i
> AI*>    N 172.16.2.252/32      0.0.0.0           100     0 i
> *       N 172.16.2.252/32      172.16.12.6       100    11 65100 i
> *       N 172.16.2.252/32      172.16.13.2       100    11 65101 i
> I*      N 172.16.2.252/32      172.16.13.5       100    11 65101 i
> I*      N 172.16.2.252/32      172.16.12.1       100    11 65100 i
>
>
> i see 2 paths with asterisk to 172.16.2.252 ,
>
> this should say loadblancing is active ?
>
>
> is there an other opportunity  to check if the bgpd have loadblancing active
> ?
>

If with loadbalancing you mean ECMP routing. Then no, bgpd does not
support equal cost multipath. Only one (the best marked '>') is used for
forwarding traffic.

There is slow work ongoing to make ECMP happen but don't expect it anytime
soon.
--
:wq Claudio