Routing

Hi,

In the Juniper advanced routing student guide, the configurations of setting the BGP Next Hop Self are as below:

{

set policy-options policy-statement next-hop-self term 1 from protocol bgp

set policy-options policy-statement next-hop-self term 1 from route-type external

set policy-options policy-statement next-hop-self term 1 then next-hop self

set protocols bgp group ibgp export next-hop-self

}

The question I am having here is:

Normally a BGP speaker would not advertise iBGP learned route to its iBGP peer, so the only bgp route advertised by the BGP speaker must be learned from its eBGP peer, which the route-type is external. Hence why we need to consider adding the route-type external as a criteria here?

Anyone could help? Thanks.

Hi,

If you have Route-Reflector or Confederation ASs in the network, the internal routes will be advertised from one peer to other. In that case, you must specify the route type "external" in the policy to change the next-hop of external routes only.

Rgds,

Moses 

Hi Moses,

Thanks for your detail explaination.  Now I understood.  Thanks again!

Regards,

Ivan