LDP over backup FRR tunnel

[Mukarram Jah Raheel]

do we need to have targeted LDP neighborship over backup FRR tunnel... ?

FRR between P & PE...

Tunnel from P to PE , if LDP is not configured Tunnel will work fine since PE can understand the VPNv4 label.

Tunnel from PE to P, LDP is a must since P cannot understand the VPNv4 label and needs an IGP label to switch correctly.

[antasson]

Hello Mukarram,

the FRR tunnel doesn't need to have LDP enabled, since it will just be used to swap the primary tunnel label with his own label during the reroute.

Therefore there's no need to exchange label informations over it.

Hope it helps,

Antonio

[Mukarram Jah Raheel]

Dear Antonio,

thank you for your reply... you are right.. i got the same clue while researching the concept...

but a little modification in your explanation...

"the FRR tunnel doesn't need to have LDP enabled, since it will just  be used to swap the primary tunnel label with his own label during the  reroute.

Therefore there's no need to exchange label informations over it."

The primary tunnel's labels are not swapped, but a new FRR-Label is imposed on top of it, therefore its like primary tunnel going through the FRR tunnel.

are LDP labels are do shared as earlier since the tunnel has been locally repaired with the purpose of keeping the primary tunnel up.... hense the primary tunnel remains up and targeted LDP neighborship too....

Regards,

Mukarram

[antasson]

Hi Mukarram,

of course you're right, I rushed a bit in the answer. Sorry for the inaccuracy.

Regards,

Antonio