Routing

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Ask questions and share experiences about ACX Series, CTP Series, MX Series, PTX Series, SSR Series, JRR Series, and all things routing, including portfolios and protocols.
  • 1.  BGP Peer A/P - Use backup ISP for some destination subnet

    This message was posted by a user wishing to remain anonymous
    Posted 03-07-2023 13:37
    This message was posted by a user wishing to remain anonymous

    Hi all,

    I need to know why my config is not working, and if you can advice me to make it correct.

    We are receiving two default routes from ISP-A and from ISP-B. The current ISP-A is preferred based on local-preference.

    I need to keep this priority, for all the traffic through ISP-A, but i want to use ISP-B as well for one destination Subnet. So default route 0.0.0.0/0 from ISP-A is injected as a primary to my Site (higher Local-Prefence).

    For this purpose I have done the configuration as below, but is not working.

    x.x.x.x is the destination_Test_IP Range that i can use for test.

    #set policy-options policy-statement ml_to_retn_condev_allow term 10 from route-filter x.x.x.x exact

    #set policy-options policy-statement ml_to_retn_condev_allow term 10 then accept

    #set policy-options policy-statement ml_to_retn_condev_deny term 10 from route-filter x.x.x.x exact

    #set policy-options policy-statement ml_to_retn_condev_deny term 10 then reject

    import this statemnt in BGP

    #set protocols bgp group Upstream neighbor 10.0.1.2 import ml_to_retn_condev_allow

    #set protocols bgp group Upstream neighbor 10.0.2.2 import ml_to_retn_condev_deny

    Now, is this possible technically and if yes, can you give us an hand regard to this by advising with the config?



  • 2.  RE: BGP Peer A/P - Use backup ISP for some destination subnet

    This message was posted by a user wishing to remain anonymous
    Posted 03-09-2023 08:24
    This message was posted by a user wishing to remain anonymous

    Hello,

    Do you receive x.x.x.x subnet from your ISP-B or only default route ? In order to work your policy you have to receive it from them. 




  • 3.  RE: BGP Peer A/P - Use backup ISP for some destination subnet

    Posted 03-10-2023 00:34

    Hi,

    The policy will not work if from the ISPs the router is just receiving a default route.

    The router must have the exact x.x.x.x prefix received from the BGP peer, for the policy to be matched.

    Regards



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    Sheetanshu Shekhar
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