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MPLS fast-reroute availablity

Hi,

Is MPLS TE fast-reroute only available on devices

with POS interfaces? I need someone to confirm this

before giving up trying to do this with routers connected only by serial links.

BTW, on a 2620 router, I created a tunnel but the

command

tunnel mpls traffic-eng fast-reroute

was not available on the tunnel interface.

Thank you,

Wei

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: MPLS fast-reroute availablity

You can use FRR over serial link. That being said the whole point of using FRR is to be able to quickly go around a circuit failure. If you rely on the HDLC keep alives to do that, it might take a while before the circuit failure is detected and for the traffic to be rerouted. One can use RSVP hellos on a serial interface to reduce the time to detect the failure.

Here's a document discussing RSVP hellos:

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1829/products_feature_guide09186a008010437a.html

As far as not being able to configure FRR on the 2600, FRR is not supported on this platform.

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
3 REPLIES
Cisco Employee

Re: MPLS fast-reroute availablity

You can use FRR over serial link. That being said the whole point of using FRR is to be able to quickly go around a circuit failure. If you rely on the HDLC keep alives to do that, it might take a while before the circuit failure is detected and for the traffic to be rerouted. One can use RSVP hellos on a serial interface to reduce the time to detect the failure.

Here's a document discussing RSVP hellos:

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1829/products_feature_guide09186a008010437a.html

As far as not being able to configure FRR on the 2600, FRR is not supported on this platform.

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
New Member

Re: MPLS fast-reroute availablity

Thanks very much. That clears things up.

I was to compare FRR with OSPF convergence to

see which is faster in time of link failures. Since

FRR is not available on the 2600s, can I assume that

there is not a big difference between the two given

the same triggering mechanism?

Wei

Cisco Employee

Re: MPLS fast-reroute availablity

FRR would still be faster than OSPF. Once the link failure has been detected, OSPF routers still have to generate new LSAs, run SPF, install the new route in the RIB and finally in the FIB. FRR only has to update the label in the FIB.

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
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