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Forum Replies

  1. Hi Rene,
    So, the sham link is required only for MPLS VPN scenario ?? Thx


  2. That’s correct. MPLS VPN PE-CE with OSPF as the routing protocol between PE/CE.

  3. Hi Rene,

    In order for redistribution other routing protocols into OSPF on CE works properly, we have to setup Sham Link. Is that correct?
    Looks like LSA type 5 & 7 are not exchanged cross MPLS backbone? Correct me if I’m wrong. Because I have tried redistribution other routing protocols into OSPF on CE without Sham Link and result is PE which connected directly with CE got the routes but other PEs didn’t got it.


  4. Hello Minh,

    Redistributed routes in OSPF on a CE router is no problem. You only need a sham link when you have a backdoor link in between your CE routers.

    By default, OSPF external routes don’t get redistributed into BGP but you can change that. Here’s a quick example:

    CE1(config)#interface Loopback 1
    CE1(config-if)#ip address
    CE1(config)#ip access-list standard CE1_L0
    CE1(config-std-nacl)#permit host
    CE1(config)#route-map CE1_L1 permit 10    
    CE1(config-route-map)#match ip address CE1_L1
    CE1(config)#router ospf 1
    ... Continue reading in our forum

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