I think I got the answer. This is because policy routing allows you to select a routing table based on the destination IP address of the packet. Route lookup using routing cache does not look up policy rules database directly so there have to be two entries in routing cache for two routes in different routing tables, the routing tables being selected on the basis of destination IP address. However the code could be optimized if policy routing is not selected during kernel compilation. Regards, Nitin > ----- Original Message ----- > From: "Nitin Jerath" <njerath@xxxxxxxxx> > To: linux-net@xxxxxxxxxxxxxxx > Subject: Routing table and routing cache > Date: Fri, 12 Jan 2007 20:34:26 +0800 > > > The linux routing table uses subnets. The routing cache entries, > however are associated with single IP addresses. > > As a result, the cache may have multiple entries belonging to the > same subnet but corresponding to different IP addresses, having the > same next hop IP address and out interface. > > What is the advantage gained by having a separate cache entry for > each destination IP address? > > -- > _______________________________________________ > Search for products and services at: > http://search.mail.com > - > To unsubscribe from this list: send the line "unsubscribe linux-net" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > = Work at Home Take paid surveys and make extra money working from home. It's fun, easy and very profitable. Up to $75 per survey. http://a8-asy.a8ww.net/a8-ads/adftrclick?redirectid=2a1fe67b0f1662dd13492746cef17d0d - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
