Please see some suggestions below. jonathan jonathan wrote: > > Hello I am in the process of setting up a lab and have found > the traditional frame switch config ie. > > Frame_Relay2521>en > Frame_Relay2521#sh run > Building configuration... > > Current configuration : 1457 > bytes > ! > version 12.2 > no service > single-slot-reload-enable > service timestamps debug uptime > service timestamps log uptime > no service password-encryption > ! > hostname Frame_Relay2521 > ! > logging rate-limit console 10 except > errors > ! > ip subnet-zero > no ip finger > ! > no ip dhcp-client > network-discovery > frame-relay switching > ! > ! > ! > ! > interface Serial0 > no ip address > encapsulation frame-relay > no fair-queue > clockrate 1000000 > frame-relay lmi-type ansi > frame-relay intf-type dce > frame-relay route 112 interface Serial1 > 211 > frame-relay route 113 interface Serial2 > 311 > frame-relay route 114 interface Serial3 > 411 > ! > interface Serial1 > no ip address > encapsulation frame-relay > clockrate 1000000 > frame-relay lmi-type ansi > frame-relay intf-type dce > frame-relay route 211 interface Serial0 > 112 > ! > interface Serial2 > no ip addre > encapsulation frame-relay > clockrate 64000 > frame-relay lmi-type ansi > frame-relay intf-type dce > frame-relay route 311 interface Serial0 > 113 > ! > interface Serial3 > no ip address > encapsulation frame-relay > clockrate 64000 > frame-relay lmi-type ansi > frame-relay intf-type dce > frame-relay route 411 interface Serial0 > 114 >
That's one way of doing a Frame Relay switch. You have chosen to forward all traffic from S3, S2, and S1 to S0. You don't have to do it that way, but it should work. > my question is how do you connect to this. On the 'client' > router how do you set the serial connections ip address. You get to plan the IP addressing you want to use, since this is a lab. There are no right answers, but some issues, as described below. > I have > set up client routers with just the dlci and lmi-type and the > line and proto goes up but how does communication work through > the cloud just by DLCI??? You don't communicate with just DLCIs, as you know. You use IP addresses. IP addresses get mapped to DLCIs in two ways: 1) With the Inverse ARP protocol which is enabled by default these days, or 2) With the "frame-relay map ip IPAddress DLCI" command. You got a great answer from someone else, but I have been thinking about this question and wanted to add a few comments. You have done your lab network design using a Bottom-Up approach. I would have recommened a Top-Down approach, but that's OK. :-) Your method will work as long as you also do some planning for the upper layers. So, you have selected a router to act as your Frame-Relay switch and have presumably cabled the DTE/DCE back-to-back cables. So the physical layer is done. The physical topology is a star, with the switch in the middle, and each router connected to a serial port on the switch. You have also chosen Data-Link Connection Identifiers for your data-link-layer Frame Relay switch. That's a good start. Now, what do you want your logical topology to be? The virtual circuits between the routers can be formed in any topology you want, partial mesh, full mesh, hub-and-spoke. It looks like you are thinking hub-and-spoke since your Frame Relay route statements on the switch seem to all point to S0. That's fine, though it's not your only option. So, in your hub-and-spoke logical topology, each spoke router will have a virtual circuit to the hub. The spokes won't have virtual circuits between each other, though. They will communicate through the hub. That's a common way of designing a Frame Relay network when connecting a company headquarters with branch offices. Now, consider network-layer addressing. Do you want all the routers to be in one subnet, where the hub-and-spoke topology emulates a LAN? That's a common solution, but it has one drawback. Frame Relay doesn't handle broadcasts as a LAN would. This causes issues for routing protocols that depend on broadcasts/multicasts for sending info and finding neighbor routers. Frame Relay is a non-broadcast, multi-access (NBMA) medium. But that's OK, you can get around this in a variety of ways. For example, with OSPF, you can tell each router who its neighbor is so they don't have to rely on multicasts to figure this out. Another option is to have the logical hub-and-spoke topology act like a set of point-to-point links. There are a variety of ways of doing this, but one typical way is to use subinterfaces at the hub. Each subinterface forms a point-to-point link with a spoke router. With point-to-point virtual circuits, broadcasting isn't an issue. There's no need to send to "everyone." There's only one device at the other end of the circuit. But the disadvantage is that each of these circuits is now an IP subnet. Without careful planning, you'll use up your subnets. For Cisco certification practice, you'll want to try a few ways of designing your lab network. After you've given some thought to logical topologies and network-layer addressing, you better decide on a routing protocol (which actually you should have alredy been considering when thinking about addressing too!) Network design is iterative. Many issues get dealt with many times. There are lots of challenges associated with getting routing protocols to work on Frame Relay, but experts on this list know how to handle all of them. For Cisco certs, you'll want to work with EIGRP, OSPF, IS-IS, and BGP. > if anyone has an example config to get my mind on the right > track i'd appreciate it. Someone else sent you a great example for hub-and-spoke. I was impressed! He spent a lot of time on a great, practical answer. > Also if i have a sub int under s0 how > can 1 physical cable connect to multiple routers??? Remember, we've moved up the layers at this point. It's not a physical cabling issue. It's a logical topology issue, that can be handled with multiple virtual circuits and subinterfaces. I hope this helped. Good luck with the lab. Keep us posted on how it goes. _______________________________ Priscilla Oppenheimer www.troubleshootingnetworks.com www.priscilla.com > thanks > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=65788&t=65713 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
