Frame Relay and multiple Frame Relay switches.

CodeBlox

I've been trying to do this in GNS3 but it doesn't seem to be working. What I've done is use various frame-relay route statements throughout the frame relay switches in an attempt to route datagrams through the frame relay network. I have three "frame relay switches" and three routers, each connected to a frame relay switch. All three frame relay switches connect to each other. Is this supposed to work in this manner where I manually configure the routes? And is this how its done in the real world? Seems really laborious. So the question is, how can I get the frame relay switches to route between other switches to the correct router? Is it accomplished through various frame relay route statements?

hiddenknight821

I'm not sure what you mean by the "frame relay switches." I am trying to figure out what you are saying here, but I'm not a great reader when it comes to deciphering someone else's written problems. You should really use technical terms like, "hub," "spokes," "full-mesh topology," or "partial-mesh topology." When I read "Frame-Relay switch," I immediately interpreted that as a frame-relay switch (with the DCE connectors) configured at the provider's end.

In your lab, you might either use a virtualized frame-relay switch that came with GNS3 (default hostname is FR1) or use a router as a frame-relay with frame-relay switching global command configured. Frame-relay switches are neither hub or spoke. Hub and spokes are the routers that are connected to the frame-relay switch.

You should check out this link from Chris Bryant. He did a pretty good job. Also, check out RouterLabs.com. On the left, you can check out one of the three links there to look through the examples. I hope I helped.

CodeBlox

I'm using routers as frame relay switches with the frame relay switching command. I was trying to use more than one in GNS3. I am NOT using the actual frame relay switch from GNS3. I'm dong this with 2691s. I have been doing all of my frame relay studies with a single router configured as a FR Switch but I am wanting to try doing it with more than one. This was intended to be a full mesh topology. I've even tried using just two frame relay switches ( routers configured with frame-relay switching command ) and in the end, I only get one active PVC and the other inactive. I am getting no tell tale signs as to why it doesn't work either.

hiddenknight821

Eh... Did you say you want to use MORE THAN ONE frame-relay switch in your topology?! That's not necessary, but I never try this before. I only use one frame-relay switch (with 3 DCE serial interfaces). I connected a hub (a router with a DTE serial interface) connected to Serial1 on FRS, and two spokes (two routers with DTE serial interface on each) connected to Serial2 and Serial3. R1, R2, and R3 should have two mapping statements each to create a full-mesh topology. You should either use multipoint with subinterfaces or physical interfaces on all routers using frame-relay interface-dlci mapping command, assuming Inverse ARP are enabled on all routers.

For DLCI numbering convention, you should use the 102 or 122 (which mean R1 to R2... see the "to" in '0' or '2' digit between '1' and '2'). This helped a lot, and it's easier to remember.

UPDATE: I forgot to add. I ran into troubles with one IOS I was using, and I dunno why I was unsuccessful with it. I tried another IOS, and it works for me. Not sure if you are experiencing the same thing. Not even sure why a "bad" IOS would be the case when most of it other features are working just fine.

CodeBlox

Yes, I am wanting to use more than one frame relay switch... I understand that it's not necessary but I would just like to try doing it. And I understand how to setup point to point and full/partial mesh frame relay topologies. As far as the frame relay switches go: If I want to use more than one, is that accomplished through multiple frame-relay route statements between these FR switches?

hiddenknight821

Well, I suppose you could according to this link. I don't understand how it works though as I'm still trying to wrap the concept around my head. CCNA doesn't expect you to know what happen if you connect a frame-relay switch to another frame-relay switch. Although, this is interesting since I didn't think of this before. However, I do know is that I can't connect a DCE to a DCE. I hope more will chime in and that they can help you.

UPDATE: Scratch that link I post. I read it again, and I realized there was no success yet.

CodeBlox

Thats the one link I found when googling too lol. Well there's another but it links to that link :P Hmm, I hadn't thought about the whole DCE-DCE thing. I will play with this some more to see if I can get it to work. I wonder if this is even remotely close to how its done in the real world. Thanks for your responses.

hiddenknight821

Well, you may be right about having frame-relay switches connected to each other since we do need redundancy in case one of the switches fail, right? That makes sense to me. However, we are not expert on frame-relay, so we wouldn't know what's happening at the providers' ends. Although, I do have this crazy idea.

Let's say FR1 is connected to FR2. Both has 4 serial ports. However, Serial4 on FR2 is configured as DTE (I know you can configure using frame-relay intf-type command). Both switches are connected by their respective Serial4 interface, of course. I think no frame-relay inverse-arp is needed on both interface along with frame encapsulation enabled.

The only trick here is that when you want R1 connected to FR1 to communicate with another router on a PVC off FR2, then you need to carefully implement the mapping command like this.

FR1: int S0/1: frame-relay route 104 interface Serial0/4 414
int S0/4: frame-relay route 414 interface Serial0/1 104

FR2: int S0/4: frame-relay route 414 interface Serial0/1 401
int S0/1: frame-relay route 401 interface Serial0/4 414

So, you might get a headache with the DLCI numbers, but if this doesn't work then I have tried my best. I'm only doing this in my head, and I felt like this would work in theory. I might have the number mixed up in the frame-relay route commands, but I hope you see where I'm getting to.