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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Peering best practices advice needed.
On Dec 8, 2004, at 12:56 PM, Richard Irving wrote: Actually, it is refreshing to see _operational_ questions on the list. :-)Please forgive the simplistic nature of the query.. This will only work if you have separate ASNs, which would be my suggested solution. In fact, even if you announce the /18 + both /19s, as long as each site as a separate ASN, it will work.Basically my company is multi-homed with 2 different providers in the UK, and advertising a /18. Now some colleaguges in another part of the world want to break that /18 into two /19's and advertise one /19 and we advertise the other. This is fine, however we are NOT running IBGP in the core, therefore the UK customers in the /19 will not be able to reach the other /19 as there would be a loop detected through EBGP. If they must have the same ASN for some reason, have your upstreams send you default route as well as a full table. You will not see the "other" /19, but you will send traffic to the upstream because of the default and they will route it properly. I've never used AS-LOOP-IN. Sorry. :(Now someone mentioned that we could use AS-LOOP-IN feature which will overcome this problem and allow us to route to each other via EBGP. I really think this is a bad idea but until we get an internal link - I dont see a way forward. So... anyone doing this currently in their network or have any "best practices" way round this. I want our company to be good Netizens but still be able to pass traffic between the 2 /19's. But I have used the above solution (and static defaults), and it works fine. -- TTFN, patrick
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