A point to point circuit is dedicated for your use. You don't have to worry about congestion in your provider's network causing you to lose data between sites. The down side is that you lose flexibility. The config is as simple as you want it to be. Router A: interface serial 0 description To Router B encapsulation hdlc ! this is the default ip address 10.1.1.1 255.255.255.0 Router B: interface serial 0 description To Router A encapsulation hdlc ! Again, this is default ip address 10.1.1.2 255.255.255.0 And that's about it for that. With frame relay, you have a T1 between your site and the provider's network. Your physical circuit can then be further broken down into what is called Permanent Virtual Circuits, or usually, PVCs. The nice thing about this approach is that the PVCs can have entirely separate and unrelated endpoints, which provides a lot of flexibility. One downside to this approach is that you are now a slave to the conditions of your provider's network. If it gets congested, you run the chance of losing data. To avoid data loss, you pay more for a higher CIR, or Committed Information Rate. This is a guaranteed amount of bandwidth that you agree to pay for. Any bursting over that limit is not guaranteed to arrive if the network is congested. A simple config for three routers might look like this: Router A: interface serial 0 encapsulation frame-relay interface serial 0.16 point-to-point description To Router B ip address 10.1.1.1 255.255.255.0 frame-relay interface-dlci 16 interface serial 0.17 point-to-point description To Router C ip address 10.1.2.1 255.255.255.0 frame-relay interface-dlci 17 Router B: interface serial 0 encapsulation frame-relay interface serial 0.16 point-to-point description To Router A ip address 10.1.1.2 255.255.255.0 frame-relay interface-dlci 16 interface serial 0.17 point-to-point description To Router C ip address 10.1.3.1 255.255.255.0 frame-relay interface-dlci 17 Router C: interface serial 0 encapsulation frame-relay interface serial 0.16 point-to-point description To Router A ip address 10.1.2.2 255.255.255.0 frame-relay interface-dlci 16 interface serial 0.17 point-to-point description To Router B ip address 10.1.3.2 255.255.255.0 frame-relay interface-dlci 17 Ok, it's that simple if you want it to be. I left out some things for the sake of clarity and I hope I didn't make any mistakes. If I did, someone please correct me. I only got three hours of sleep last night and I shouldn't be configuring anything off the top of my head! A couple of things to notice about these configs: first, the subinterface numbers can be anything you want. I could have used "interface serial 0.67" if I'd wanted, but it's a good practice to make the subinterface number match the dlci, which you get to pick most of the time but sometimes it will be provided to you. The first usable dlci number is 16, so I used that in these configs. Second, the dlci has only local significance. This means that if dlci 16 on router A leads to router B, on router B's end it doesn't have to be dlci 16. It could just have easily been dlci 95. It's entirely irrelevant. I hope that helps, and that I answered your question. I probably went off on a tangent and answered questions you weren't asking, but that's only because I really, REALLY need some sleep! Good luck! John Neiberger, CCNA/CCDA _______________________________________________________ Get 100% FREE Internet Access powered by Excite Visit http://freelane.excite.com/freeisp ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
