it seems that FRR's latest version, there is a problem with l3vpn vpn over mpls. based on this topology :
https://forum.vyos.io/t/vyos-1-4-l3vpn-bgp-import-export-nexthop-incorrect/9876
it looks like with control-plane all is working , however , it couldn't send traffic over this PEs :
```
vyos@cust-pe2:~$ show configuration commands | match " bgp| mpls"
set protocols bgp neighbor 10.255.254.2 address-family ipv4-unicast
set protocols bgp neighbor 10.255.254.2 address-family ipv4-vpn nexthop-self force
set protocols bgp neighbor 10.255.254.2 address-family ipv4-vpn soft-reconfiguration inbound
set protocols bgp neighbor 10.255.254.2 description 'MPLS'
set protocols bgp neighbor 10.255.254.2 disable-connected-check
set protocols bgp neighbor 10.255.254.2 remote-as '64532'
set protocols bgp neighbor 10.255.254.2 update-source 'dum20'
set protocols bgp parameters log-neighbor-changes
set protocols bgp parameters router-id '1.1.1.1'
set protocols bgp system-as '64532'
set protocols mpls interface 'eth0'
set protocols mpls interface 'dum20'
set protocols mpls ldp discovery transport-ipv4-address '1.1.1.1'
set protocols mpls ldp export ipv4 explicit-null
set protocols mpls ldp interface 'eth0'
set protocols mpls ldp interface 'dum20'
set protocols mpls ldp router-id '1.1.1.1'
set vrf name customer protocols bgp address-family ipv4-unicast export vpn
set vrf name customer protocols bgp address-family ipv4-unicast import vpn
set vrf name customer protocols bgp address-family ipv4-unicast label vpn export 'auto'
set vrf name customer protocols bgp address-family ipv4-unicast network 5.5.5.5/32
set vrf name customer protocols bgp address-family ipv4-unicast network 10.180.50.0/24
set vrf name customer protocols bgp address-family ipv4-unicast rd vpn export '1:2'
set vrf name customer protocols bgp address-family ipv4-unicast redistribute connected
set vrf name customer protocols bgp address-family ipv4-unicast route-target vpn export '1:2'
set vrf name customer protocols bgp address-family ipv4-unicast route-target vpn import '1:2'
set vrf name customer protocols bgp parameters router-id '10.180.50.50'
set vrf name customer protocols bgp system-as '64531'
```
this case is related to another task, where we can advertise using network command :
https://phabricator.vyos.net/T4846
I've made some test 8.2.2 , it works without problems . I'll open a case with both bugs .