Hi Thiru,
well first of all i would like to make a point here that you cannot achieve failover/convergence between Reliance and TATA at SP level due to the fact they being strategically different telcos.
Secondly i agree with Sultan for chasing the SP to tune their parameters for better convergence within their network.
From your side you can you can use commands like backbone fast on trunk interfaces connecting SP
However in context to the Converstation topic - Metro: Failover takes long time across different Metro ethernet link , if you want to achieve failver between two providers or ethernet links i would suggest following :-
What service provider would provide u would be either ERS ( opaque to customer BPDUs ) or EWS ( transperent to customer BPDUs ) in their L2 vpn offerings. These are basically psuedowires over mpls networks.
In such setups , typically a customer is connected to U-PE which is backhauled to PE which is connected to MPLS network of SP. The link between U-PE and PE would be ideally a trunk and link between customer and U-PE port on which customer is connected would be either access-port in case of ERS or trunk-port in case of EWS or depending on number l2 ckts of ERS or customer is buying from the SP.
In this solution there is an inherent problem of O&AM where a port connected to user DOESNT GO DOWN even if there is problem in L2 ckts or vc/vlan being used in l2 ckt over the MPLS network and hence you dont get any trigger of port/protocol going down as seen traditionally in serial or atm or fr links.
You need to achieve failover at your level i.e on ur CE connected on both end of L2 vpns from these two providers on the basis of service ( ERS or EWS ) taken from the provider
For ERS ( suggested using router )
=======
assumming that you have routers connected behind ur l2 vpns
CE-A-P1-|PE------ l2 Rel ------PE|-CE-B-P1
CE-A-P2-|PE------ l2 Tata ------PE|-CE-B-P2
You can look forward for following things to achieve quick failover and redundancy over your l2 links using :
1) dynamic routing protocol
2) rtr / track function of cisco ios to track the next hop and switch between routes to destination
3) GRE tunnel over ethernet links and use of floating routes by tracking the state of GRE tunnel using keep-alives
For EWS ( suggested using l2 switch )
=======
SW-A-P1-|PE------ l2 Rel ------PE|-SW-B-P1
SW-A-P2-|PE------ l2 Tata ------PE|-SW-B-P2
As mentioned above EWS is transperent to customer bpdu and
hence I would propose that you can try running your own STP which is tunneled into the EWS over MPLS. Hence you achieve failover at l2 level too.
I have never tried this soln , I would suggest you try the same and check the success !!! , but i can suggest that theoritcally the operation would be like.:
1) When both the links are UP
- Either of the switches would be a root and one of the link would be in forwarding and other shall be in blocking as per STP calculations
2) When one of the link goes down due to a) physical port connecting the SP goes down b) VC/Vlan over SP MPLS network going down
- In case (a) the second port connecting the other end of your switch will take over from blocking to forwarding mode
- In case (b) the port which ( SW-A-P1 ) was in forwarding mode shall not recieve bpdu over that link and after some time it will force the re-calculation of STP and the second port ( SW-A-P2 ) shall become forwarding and link is switched over. In this case though the initial port will still remain in forwarding mode but as there is no BPDU being recieved over that port there will be no transfer of data . Please avoid using spanning tree bpdufilter on these ports.
3) When the broken link as per pt no 2 comes UP again
- SW-A-P1 again starts recieving the BPDU and due to spanning tree active the second port ( SW-A-P2 ) goes into blocking mode.
I would still suggest to use router as CPE in both scenarios ( EWS /ERS )
RAJ
