It is absolutely not what people do, at least they better not be doing that. Think about this. The current BGP route table is about 100,000 routes. If you want redundancy, that means multiple routers as ASBR's, and if you're talking OSPF as an IGP, then each ASBR then has to generate a type-5 LSA for each of those BGP routes. Therefore that means having hundreds of thousands of type-5 LSA's running around on your network - can you imagine? Just thinking about it makes me shudder. Of course you might say that you might try to summarize those LSA's by using totally stubby areas. Well, first of all that doesn't exactly help your core (area 0 can't be stubby), and second of all if you were going to use default routes anyway (via totally stubby ABR's), then why not forgo redistribution completely and just have your ASBR's inject defaults?
""Alex Lei"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Steve, > > Why is redistribution into an IGP a big no - no? My understanding is that > this is what people usually do. > > If you use OSPF and E2 routes on the third router, then OSPF should find the > optimal route. > > Alex > > Steven A. Ridder wrote: > > > > If I had 2 7206 routers dual homed to two different ISP's for > > redundancy, I > > know I don't NEED the full bgp table, but if I were to accept > > them for > > optimal routing within my network, how would I tell my internal > > routers who > > don;t run BGP which of the two 7206 routers to go to for a > > specific route > > oout to the internet? I assume doing a redistribution into the > > IGP is a big > > no-no, so how do small 3600's and 2600's inside the AS know > > which of the two > > routers to send the traffic to based on the fact that that one > > router has > > the better route? > > > > I can think of adding a third 7206 router which would run BGP, > > connect to > > the other two routers and accept the full table as well, and > > the internal > > routers would use that one as the gateway to the internet, but > > if I didn't > > have that third router, is there any other way? > > > > -- > > > > RFC 1149 Compliant. > > Get in my head: > > http://sar.dynu.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=40566&t=40525 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
