Hello,
@euxyabe wrote:
"bgp-igp-both-ribs BGP and IGP destinations with routes in both routing tables" which is explained by Junos.
How to understand it ? what kind of action will take place ?
This option copies all LDP/RSVP routes usually placed only in inet.3 also into inet.0.
End result is You have LDP/RSVP routes also in inet.0 and available for export into BGP-LU.
This is useful if You have >1 hop between ASBR and PE and have to ensure there is a valid labeled path from ASBR to PE.
Otherwise, if Your LDP/RSVP breaks between, say, ASBR1 and PE3, and ASBR1 continues to announce PE3 loopback (seen as OSPF route on ASBR1) to AS65002, then VPN traffic from AS65002 destined to PE3 will exit ASBR1 single-labeled. This is not a problem with direct PE3-ASBR1 connection but if there is a intermediate router between PE3 and ASBR1, then Your VPN traffic will be blackholed on that intermediate router because it has no knowledge of PE3' VPN label.
In case You use "bgp-igp-both-ribs" knob AND have an intermediate router AND export LDP loopbacks from ASBR1 to AS65002, then if labeled path between PE3 and ASBR1 breaks, then VPN traffic from AS65002 destined to PE3 will fail over to ASBR2.
Hope this makes sense,
Thanks
Alex