Interesting. I don't work for an ISP bt have worked with many and I have only ran into one that ran an IGP with it's customers and I was suprised. My ancedotal evidence suggests that the vast majority either run BGP or statics to announce customer networks. I know there are plenty of ISP engineers out there and can confirm/rip my conjecture ;)
Dave Mike Bernico wrote: > > I'm not sure I'm in complete agreement. The network I work for has several > distribution routers that contain around 1000 T1 speed customers. If we > were to static route each of their networks it would add about 1000 to 1500 > lines of router configuration to the router. That would definately add to > our maintenance and provisioning work and make troubleshooting harder on our > techs. While I agree statics are probably the most stable way, I'm not > sure it's necessarily the best way to aggrigate high volumes of customers. > We currently use EIGRP at the edge with the stub command, OSPF or IS-IS > would work just as well. Regardless, we would never let our IGP, that > extends to the CE router, touch their IGP. About 98% of our customers are > not BGP customers though. > > YMMV > Mike > > ------------------- > Mike Bernico [EMAIL PROTECTED] > Illinois Century Network http://www.illinois.net > (217) 557-6555 > > > -----Original Message----- > > From: Howard C. Berkowitz [mailto:[EMAIL PROTECTED]] > > Sent: Monday, September 30, 2002 11:37 AM > > To: [EMAIL PROTECTED] > > Subject: Re: OSPF for ISPs [7:54540] > > > > > > At 2:58 PM +0000 9/30/02, Don wrote: > > >Rather than run OSPF to customers, it is generally much > > better to have > > >them use a default route to the ISP and for the ISP to run > > static routes to > > >the customer. OSPF to the customer is a huge land mine for > > the ISP and > > >should be avoided in almost every case. > > > Don > > > > I agree completely with Don that an ISP _never_ should link its IGP > > to that of the customer. Don't fall into the trap of assuming that > > BGP needs a full routing table or will consume excessive resources. > > > > I remain confused why a default route wouldn't serve, unless there > > are multiple connections between the ISP and customer. By "send the > > block to the customer," do you mean the block is in the customer's > > space? You could certainly use a second static route, which can be > > generated automatically as part of your address assignment (see my > > NANOG presentation, > > http://www.nanog.org/mtg-9811/ppt/berk/index.htm). > > > > If that's not appropriate, have the customer announce his two blocks > > to you with BGP and receive default from your BGP. > > > > > > > > > > >""Chris Headings"" wrote in message > > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > >> Good morning all. I was wondering if someone could lend > > me a little help > > >> about engineering OSPF in the backbone for an ISP > > network. I just had a > > >> couple of questions and hopefully someone can give me > > some guidance.or > > >even > > >> some CCO links with some specific examples or better yet > > any material > > >> anywhere. > > >> > > >> Say, for example, that a customer has a small block of IP's and a > > >> distribution router knows where that block is, via a > > connected route, > > like > > >a > > >> /30 on a serial link. But later down the line the > > customer requests an > > >> additional block of 64 IP addresses, what is the best way > > to send this > > >block > > >> to the customer? Do I need to run OSPF on the customer > > equipment? If > > the > > >> customer router is not running OSPF, how do the routers > > know how to get > > to > > >> this destination? I assume via static routing??? > > >> > > >> Thanks as always. > > >> > > > > Chris -- David Madland CCIE# 2016 Sr. Network Engineer Qwest Communications 612-664-3367 "You don't make the poor richer by making the rich poorer." --Winston Churchill Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=54559&t=54540 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
