We take several upstream connections via BGP and notice the number of routes growing rapidly. It was around 160-170K 6 months ago and is now 182K and growing.
Should we really keep all of these routes or is there som sensible way to keep say 150K of the most common and a default route for the rest?
Thanks Gary
Are you concerned about the memory on your router? What type of router and how much DRAM does it have installed? Are you using soft-reconfiguration? Depending on your providers, you could ask for partials + a default route. You will lose some load-balancing though.
Regards, Steve
I would consider implemnting NETFLOW AS aggregation to see to which ASs the majority of your data flows. Those ASs would be the ones whose BGP routes you should accept in case you want to move away from full routes.
We run 6500's with lots of memory but just trying to ease the load. yes we do use soft configuration.
Thanks Gary
Moving to partial + default would require some careful planning.
Who would generate default - local or ISP received via BGP
If ISP how does ISP generate - if from POP router only - blackhole scenario if POP becomes partioned from ISP's network ...
My preferred approach in this situation is to accept full routes but filter them to a path length of two or three AS. I also let in a few "far" routes which I use to determine that the POP has connectivity to the Internet and can be used as a default route. This lets in "local" routes while avoiding trying to keep the entire routing table in memory. It won't help you if you need to use "soft reconfiguration."
Good luck and have fun!
i cant wait until IPV6 takes hold... we will probably have like 182k per city.. cisco needs that 1TB ram router yesterday! LOL
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.