""KW S"" wrote in message ... > What is the benefits of receiving the following BGP routes > 1. Full routes > 2. Partial routes > 3. No routes
Well #3 means it doesn't work (you need at least a default route, or 0.0.0.0/0), so I'll skip that one....... Full routes from two or more providers, with no default route: Benefits - Ability to move any prefix/AS for outbound traffic to any of the providers. Abilty to optimize/maximize loose-mode uRPF features. Ability to optimize/maximize prefix-filters/distribute-lists if you are a transit-AS. Ability to route 0.0.0.0/0 to Null0, aka "The Default Free-Zone, or DFZ" Drawbacks - More routes = more CPU and memory requirements on your routers. However, scaling with today's equipment and a few good configurations makes this a very small issue compared to the power you gain Application - Tier 1 Internet Provider that doesn't receive partial routes from anyone and gets a full routing table from all peers Some Full routes, some Partial routes, no defaults: Benefits - Ability to move any prefix/AS on providers receiving full routes and some ability to move onto providers sending partial routes. Ability to route 0.0.0.0/0 to Null0, which is sort of like "default-free" Drawbacks - Can't use loose-mode uRPF on all providers (but could build a complicated strict-mode uRPF for the partial route providers). Prefix-lists and distribute-lists also become more complicated if you are a transit-AS Application - Tier 2 Internet Providers, Content Providers, any company with IP clue Partial routes from two or more providers, with partial+default route from one provider: Benefits - Ability to move around some prefixes/ASes for outbound traffic to the providers that will take that prefix/AS. Ability to send the rest of your traffic out the default route to the one provider Drawbacks - Restriction to send the rest of your traffic out the default route of only one provider Application - Companies with IP clue that don't have the money to keep all routers configured properly or with enough memory to hold full tables with multiple views Partial routes from two or more providers, with more than one provider sending partial+default routes: Benefits - Ability to move around some prefixes/ASes for outbound traffic to the providers that will take that prefix/AS. Ability to send the rest of your traffic out any of the default routes from the providers you are getting defaults from Drawbacks - More than one default route can be confusing to deal with Application - Companies that don't understand how partial+default works Partial routes from one or more providers, with another single provider providing only a default route: Benefits - As Partial, with partial+default from one provider, only that provider doesn't send partial routes. Drawbacks - Restriction to default route for rest of traffic Application - Companies with IP clue, but very little money and resources (read: only have Cisco 2500 routers or equivalent) Default routes from two or more providers with no full/partial routes: Benefits - you are multihomed (not reliant on one Internet provider), but only in the smallest sense of the term Drawbacks - no ability to influence traffic Applcation - Companies who are willing to spend the extra cost associated with two providers, but aren't willing to upgrade their Cisco 2500 router that has 2MB DRAM -dre Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71484&t=71442 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
