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Forum Replies

  1. It’s mostly used to prevent routing loops or sub-optimal routing paths that are caused by redistribution. Asymmetric routing doesn’t have to be a problem…when using IGPs (OSPF / EIGRP) you will mostly see symmetric routing but with BGP, asymmetric routing is likely to occur.

  2. Can you confirm if this is my correct reading of this route-map
    Networks from Protocol B ‘Jack’ are untagged until they enter Protocol A where they are Tagged - (The first statement is ignored because they are not Tagged)

    Jack(config)#route-map TAG permit 20
    Jack(config-route-map)#set tag 1 

    When these now Tagged routes hit ‘John’ Still in Protocol A they are denied from re-entering Protocol B via the First statement.

     route-map TAG deny 10
        John(config-route-map)#match tag 1

    But as you say the route-map has to deny the Tagged routes first or it will allow

    ... Continue reading in our forum

  3. Hello Rene,

    I have intlo0 with ip address of

    I have access-list 1 permit and route map route-map TST permit
    route-map TST
    set tag 222

    match ip address 1
    set tag 111

    and redistribute into ospf from eigrp

    redistribute eigrp 100 subnets route-map TST

    but at the destination router I only see tag 222 for the prefix instead of 111

    as son as I change the access list wild card mask to the destination router sees the correct tag of 111

    Could you please explain this why with wilcard the correct tag is not shown but wit

    ... Continue reading in our forum

  4. Hi Rene,
    Please please help me out regarding redistribution. when redistributing mutually between ospf and bgp by tagging and i m getting an error

    % “TAG1” used as redistribute ospf into bgp route-map, set tag not supported"

    route-map TAG1 deny 10
    match tag 1
    route-map TAG1 permit 20
    set tag 1


    according to the topology, I have to redistribute mutually bet OSPF and BGP at R3 and R4. I have to advertise from R3 and R4 towards R1 and R2. s

    ... Continue reading in our forum

  5. Hi Abdus,

    Route tagging when redistributing into BGP is not supported. That’s why you get that error:

    R1(config)#route-map SET_TAG permit 10
    R1(config-route-map)#set tag 10
    R1(config)#router bgp 1
    R1(config-router)#redistribute ospf 1 route-map SET_TAG
    % "SET_TAG" used as redistribute ospf into bgp route-map, set tag not supported

    You can use something else in BGP to “tag” redistributed routes, like a community value. Between OSPF and EIGRP, you can use tags to prevent routing loops.

    Let’s think about the things that could go wrong in a topology like this if

    ... Continue reading in our forum

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