bgpd: fix export, and selects l3vpn aggregated prefix

On a L3VPN setup, an aggretated prefix can not be exported and selected.
The below example illustrates the 172.31.0.0/24 aggregated prefix, which
is valid as a VRF prefix, but invalid as a VPN prefix:

> r1# show bgp ipv4 vpn 172.31.0.0/24
> BGP routing table entry for 444:1:172.31.0.0/24, version 0
> not allocated
> Paths: (1 available, no best path)
>   Not advertised to any peer
>   Local, (aggregated by 65500 192.0.2.1)
>     0.0.0.0 from 0.0.0.0 (192.0.2.1) vrf vrf1(4) announce-nh-self
>       Origin incomplete, metric 0, weight 32768, invalid, sourced,
local, atomic-aggregate
>       Extended Community: RT:52:100
>       Originator: 192.0.2.1
>       Remote label: 101
>       Last update: Mon Mar  3 14:35:04 2025
> r1# show bgp vrf vrf1 ipv4 172.31.0.0/24
> BGP routing table entry for 172.31.0.0/24, version 1
> Paths: (1 available, best #1, vrf vrf1)
>   Not advertised to any peer
>   Local, (aggregated by 65500 192.0.2.1)
>     0.0.0.0 from 0.0.0.0 (192.0.2.1)
>       Origin incomplete, metric 0, weight 32768, valid, aggregated,
local, atomic-aggregate, best (First path received)
>       Last update: Mon Mar  3 14:35:03 2025
> r1#

Actually, the aggregated prefix nexthop is considered, and 0.0.0.0 is
an invalid nexthop.

> r1# show bgp vrf vrf1 nexthop
> Current BGP nexthop cache:
>  0.0.0.0 invalid, #paths 1
>   Is not Registered
>   Last update: Thu Feb 13 18:33:43 2025

Fix this by considering the L3VPN prefix selected, if the VRF prefix
is selected too.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

0 files changed, 0 insertions, 0 deletions