On 14/07/2014 18:32, Jeff Tantsura wrote: > BGP to RIB filtering (in any vendor implementation) is targeting RR which > is not in the forwarding path, so there¹s no forwarding towards any > destination filtered out from RIB. > Using it selectively on a forwarding node is error prone and in case of > incorrect configuration would result in blackholing.
there are other drawbacks too: the difference in convergence time between < 24k prefixes and a full dfz is usually going to be large although I haven't tested this on an me3600x yet. Also these boxes only have 1G of memory might be a bit tight as the dfz increases. For sure, it's already not enough on a bunch of other vanilla ios platforms. Nick > > Cheers, > Jeff > > > > > -----Original Message----- > From: Mark Tinka <mark.ti...@seacom.mu> > Organization: SEACOM > Reply-To: <mark.ti...@seacom.mu> > Date: Tuesday, July 8, 2014 at 1:56 PM > To: "nanog@nanog.org" <nanog@nanog.org> > Subject: Re: Best practice for BGP session/ full routes for customer > >> On Monday, July 07, 2014 08:33:12 PM Anurag Bhatia wrote: >> >>> In this scenario what is best practice for giving full >>> table to downstream? >> >> In our case, we have three types of edge routers; Juniper >> MX480 + Cisco ASR1006, and the Cisco ME3600X. >> >> For the MX480 and ASR1006 have no problems supporting a full >> table. So customers peer natively. >> >> The ME3600X is a small switch, that supports only up to >> 24,000 IPv4 and 5,000 IPv6 FIB entries. However, Cisco have >> a feature called BGP Selective Download: >> >> http://tinyurl.com/nodnmct >> >> Using BGP-SD, we can send a full BGP table from our route >> reflectors to our ME3600X switches, without worrying about >> them entering the FIB, i.e., they are held only in memory. >> The beauty - you can advertise these routes to customers >> natively, without clunky eBGP Multi-Hop sessions running >> rampant. >> >> Of course, with BGP-SD, you still need a 0/0 + ::/0 route in >> the FIB for traffic to flow from your customers upstream, >> but that is fine as it's only two entries :-). >> >> If your system supports a BGP-SD-type implementation, I'd >> recommend it, provided you have sufficient control plane >> memory. >> >> Cheers, >> >> Mark. > >
