At 6:32 PM -0400 5/10/02, dre wrote: >""Chris Headings"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> We are an ISP in So. Cal. We are gearing up to open other offices in >> bewteen Arizona and Ca... >> >> We are trying to decide what would be the best way of intergrating our ISP >> network...like... >> >> Should we just continue to use our one ASN and have all traffic come back >to >> the Global NOC, or should get new ASN's for each location??? > >Philip Smith's Multihoming NANOG presentation covers disconnected backbones >and ASN usage.
There's also the "IOS Essentials Every ISP Should Know," the URL for which I don't have handy but is at Cisco, as well as the ISP Workshop series. > >> Should we be using IS-IS, IBGP/EBGP, OSPF as the protocol to link all >remote >> locations??? > >Yes. If you can afford it (and I can't see why you wouldn't be able to), >you should >have all routers take part in IBGP. Just to clarify something I'm sure dre well knows, having all routers participate in iBGP doesn't mean they have to be in a flat topology. The rough rule of thumb has long been you don't want more than 20-30 BGP sessions of any type on one physical router, which is the motivation for iBGP scalability techniques such as confederations and route reflectors. Of course, this is a worst-case number, tending to assume full routes and a lot of churn. You could probably get away with a good deal more if you're just having eBGP connections to customers advertising their own routes and accepting default. Some of the scalability issues are in the IETF BMWG drafts (http://www.ietf.org/html.charters/bmwg-charter.html). We've done eBGP first, but the terminology draft is relevant to both eBGP and iBGP, and the appendix to the eBGP methodology draft gives some typical sizing. >Doesn't matter about the IGP, some >people >prefer IS-IS, and others prefer OSPF. GlobalCrossing and AboveNet (and >probably >other ISP's) had to move to IS-IS eventually, and migration is terrible. If >you have >the knowledge or time to invest in IS-IS, I would suggest looking into that >as an option >before your network grows too large. Fortunately, there are a lot of really >good >resources out there today (for both IS-IS and OSPF, actually ;> ). > >> Obviously cost in an issue, but throwing cost out the door, what is the >> ideal way of linking ALL offices, using a good level of redundancy and >great >> preformance... > >Metro Ethernet and wavelength services make purchasing distance bandwidth a >lot >easier. Co-location has also come a long way, making transit and peering >very easy >and cost effective. You are no longer being forced to connect into some >strange, >unknown remote POP via costly (and difficult to provision) SONET circuits >and router >interfaces. Look into your Exchange Points and Metro Providers (CLEC's for >fiber and >optical wavelengths) possibilities. Very valid points. There's a lot of discussion of exchange points at www.ripe.net. Exchange points operated by many organizations are more common in Europe than in the US, and indeed there's now a European Exchange Operators Forum (or something along those lines -- you can find it at RIPE). When doing these things, also think about local loop diversity. -- "What Problem are you trying to solve?" ***send Cisco questions to the list, so all can benefit -- not directly to me*** ******************************************************************************** Howard C. Berkowitz [EMAIL PROTECTED] Chief Technology Officer, GettLab/Gett Communications http://www.gettlabs.com Technical Director, CertificationZone.com http://www.certificationzone.com "retired" Certified Cisco Systems Instructor (CID) #93005 Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=43916&t=43836 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
