BGP next-hop self benefits

Saku Ytti saku at ytti.fi
Mon Dec 4 09:41:14 CST 2017


I'd like to add that one major advantage is limiting next-hops, thus
labels in your network. This is not just theoretical concern but there
are plenty of practical networks using practical hardware where you
simply cannot expose all next-hops to every node.



On 1 December 2017 at 17:30, Ken Chase <math at sizone.org> wrote:
> On an IX, without next-hop-self peer A leaking peer B's routes they receive to
> C will have C send direct to B on the IX (assuming flat layer 3 addressing,
> and not multiple little /30s or /96s everywhere or something - do any
> exchanges do that?)
>
> This may seem more efficient than sending C's traffic to A to get to B (pumping up
> the IX's usage graphs) but B may not have peering agreements with C.
>
> Setting next-hop-self avoids this. An 'advantage' in some views. Not related to
> n-h-s in an igp specifically, but an interesting (mis)use case.
>
> /kc
>
>
> On Fri, Dec 01, 2017 at 03:06:34PM +0000, craig washington said:
>   >Hello everyone,
>   >
>   >
>   >Question, what are the true benefits to using the next-hop self feature, doesn't matter what vendor.
>   >
>   >Most information I see is just to make sure you have reach-ability for external routes via IBGP, but what if all your IBGP knows the eBGP links?
>   >
>   >Is there a added benefit to using next hop self in this situation?
>   >
>   >
>   >Any feedback is much appreciated, either for the question specifically or whatever else you got ????, L3VPN's or underlying technology that has to have that.
>   >
>   >
>   >Thanks
>   >
>   >
>
> --
> Ken Chase - math at sizone.org Guelph Canada



-- 
  ++ytti


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