I apologize for taking so long to respond. When I was referring to the amount of peering I meant the iBGP peering, not eBGP peering. When you say a unified IGP, you are making the assumption that all customer routes are carried in BGP, correct? I also wanted to clarify something. How are we defining an ISP? Are we considering UUnet and Sprint to be ISPs, or are they in a different category all together? Would a network of that size also run only a single instance of an IGP, assuming that they only carry internal links and loopbacks within it? ~-----Original Message----- ~From: Phillip Heller [mailto:[EMAIL PROTECTED]] ~Sent: Wednesday, July 10, 2002 10:25 PM ~To: [EMAIL PROTECTED] ~Subject: Re: Route Reflection with Multiple POPs [7:48509] ~ ~ ~On Thu, Jul 11, 2002 at 01:28:08AM +0000, Lupi, Guy wrote: ~ I had a feeling that would happen, I will try to clarify. I ~was not trying ~ to say that there should be a central core site for the ISP's entire ~ network, but for pieces of it. Lets take a state like New ~York, within it ~ you have 3 POPs, each is in it's own AS and runs an IGP. In ~each POP you ~ have 2 core routers and 3 aggregation routers, the 2 core ~routers have EBGP ~ connections and are reflectors for the 3 aggregation ~routers. Now you want ~ all 4 POPs to be in the same AS, and they have to have ~direct connectivity ~ to your 3 New Jersey POPs which should also be in the same ~AS. In that ~ case, would it make sense to choose a NY POP and a NJ POP, ~install 2 core ~or ~ backbone routers that do not participate in any IGP, use ~those to peer with ~ the POPs in that state and in turn peer with the other ~state's core or ~ backbone routers? This would significantly reduce the ~amount of peering ~ that would be required. Hopefully the drawing won't be a disaster. ~ ~ NY POP 1 NJ POP 1 ~ o o o o ~ o o ~ o o o o ~ ~ NY POP 2 NJ POP 2 ~ o o o-------------------o o o ~ o \ / o ~ o o / \ o o ~ o-------------------o ~ ~ NY POP 3 NJ POP 3 ~ o o o o ~ o o ~ o o o o ~ ~ ~Are you suggesting seperate per-pop AS's as a result of ~confederations, or otherwise? Confederations will certainly work, but ~may be overkill for a 6 pop regional network. ~ ~I would suggest a single externally visible AS with a unified IGP. IGP ~convergence time is much preferrable to BGP convergence time. ~Also, BGP ~is better suited for political/administrative division, which shouldn't ~be necessary between the two regional networks. ~ ~Also, when you say "...reduce the amount of peering...", are you ~referring to the number of ibgp sessions, external peering ~arrangements, ~or transit connections? ~ ~--phil ~ ~ ~ ~
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