База знаний

/routing filter rule
add chain=bgp_in comment="Nexthop to ISP" disabled=no rule="set gw <next-hop>; accept;"
add chain=discard disabled=no rule="reject;"

/routing bgp template
add as=<ваш-asn> disabled=no name=bgpcast output.network=bgp-networks .no-client-to-client-reflection=yes routing-table=main

/routing bgp connection
add as=<ваш-asn> cisco-vpls-nlri-len-fmt=auto-bits connect=yes disabled=no hold-time=4m input.filter=bgp_in instance=bgp-instance-bgpcast keepalive-time=1m listen=yes \
    local.address=<ваш-ip> .role=ebgp multihop=yes name=bgpcast output.filter-chain=discard .network=bgp-networks .no-client-to-client-reflection=yes \
    remote.address=<bgpcast-ip> .as=<bgpcast-asn> routing-table=main templates=bgpcast vrf=main

/routing/bgp/session/print

route-map bgpcast-in permit 10
 set ip next-hop <next-hop>
!
route-map bgpcast-out deny 10

router bgp <ваш-asn>
 neighbor <bgpcast-ip> remote-as <bgpcast-asn>
 neighbor <bgpcast-ip> ebgp-multihop 255
 address-family ipv4 unicast
  neighbor <bgpcast-ip> activate
  neighbor <bgpcast-ip> route-map bgpcast-in in
  neighbor <bgpcast-ip> route-map bgpcast-out out
  neighbor <bgpcast-ip> soft-reconfiguration inbound
 exit-address-family

vtysh -c 'show bgp summary'

protocol bgp bgpcast {
  local as <ваш-asn>;
  neighbor <bgpcast-ip> as <bgpcast-asn>;
  multihop 255;
  ipv4 {
    import filter { gw = <next-hop>; accept; };
    export none;
  };
}

birdc show protocols all bgpcast