Routing

Hi Sir,

I've gone through some of the article here and need more information and clarification of BGP default route and MD5. Currently my bgp router peer with two upstream and received full routing table and everthing run smoothly. I've customer request for BGP peering and request for only default route and accepting MD5.

BGP Default Route.

I have never advertise default route to bgp peer.

1. What should I do to advertise only default route to my customer, do I need to create default route policy and apply this policy to customer external bgp peer and just that? Example configuration please.

2. How do check that I have advertise customer default route. For information currently my bgp router only advertised 1 prefix.

3. Can I check and verify my upstream also advertise default route to me, if iam receiving full route doesnt mean I'm also receiving default route?

MD5

Never implement this. If customer request md5 authentication , what shall i do to proceed with this MD5.

Hope someone could assist and help me further.

Thank you sir.

Regards,

chenoi

Hi Chenoi,

If the objective is the advertise only default route to the customer and block all other prefix, then below configs should help you: (this includes MD5 authetication too)

[edit]
user@PE1# show protocols bgp
group int {
    multihop;
    export BGP_ADV;
    neighbor 2.2.2.2 {
        local-address 1.1.1.1;
        authentication-key "$9$Fb7o6CuKvLXNbev4aGUHkuOB"; ## SECRET-DATA
        peer-as 200;
    }
}

[edit]
user@PE1# show policy-options policy-statement BGP_ADV
term a {
    from {
        protocol aggregate;
        route-filter 0.0.0.0/0 exact;
    }
    then accept;
}
term b {
    then reject;
}

[edit]
user@PE1# show routing-options aggregate
route 0.0.0.0/0 discard;

And to verify that you are advertising default route, you can use below command:

[edit]
user@PE1# run show route advertising-protocol bgp 2.2.2.2

inet.0: 40 destinations, 40 routes (39 active, 0 holddown, 1 hidden)
  Prefix                  Nexthop              MED     Lclpref    AS path
* 0.0.0.0/0               Self                                    I

In similar way you can use below command to check if you are receiving any default route from upstream peer:

show route receive-protocol bgp <BGP_PEER_ADDR> 0/0

Regards

Surya

Hi Surya,

Thank you for your prompt reply and I will test this further. 

Thank you for your help and kind assistance.