Help !! I cannot get my Frame Relay lab to work...

[Renne Stuart]

I am trying to set up a lab to help me with studying for the Router exam and have created a Frame Relay Switch using a 2611XM with 3x serial ports connected to 3x Cisco 1760's. I have found lots of different ways of configuring the lab on the internet and I still cannot get the links to go to "Active", I have attached the configs from the Frame Relay Switch and the 3 Routers trying to connect into the Frame Relay cloud. I would appreciate it if someone could take a look and let me know where I am going wrong.

Thanks

Renne

[cadet alain]

Hi,

Try this:

[Renne Stuart]

Can you not do this without the static mapping?

[andrew.prince]

A basic example:-

R1 <> R2

R1 = DLCI 102

R2 = DLCI 201

FRS serial 1/0 = R1

FRS serial 1/1 = R2

interface s1/0

frame-relay route 102 interface serial 1/1 201

interface serial 1/1

frame-relay route 201 interface serial 1/0 102

frame-relay route ### (incoming DLCI info) interface serial (the outgoing interface ) ### (the out going DLCI)

HTH>

[Arber_123 · Accepted solution]

Hello,

I think you are doing it in the wrong way. I see from the config of the FRS that you want to create a full mesh F-R cloud, but the dlci assignment is not correct.

In order this to work you have to plan, how many PVC you want, what DLCI and in which interfaces, then create the required frame-relay routes.

Let take an example:

==========FRS Config==============

frame-relay switching

interface serial 1

encapsulation frame-relay

clock rate 128000

frame-relay intf-type dce

frame-relay route 102 interface serial2 201             //Every frame that comes with DLCI 102 goes to interface Serial2 with DLCI 201 in F-R header in it.

interface serial 2

encapsulation frame-relay

clock-rate 128000

frame-relay intf-type dce

frame-relay route 201 interface serial1 102           //Every frame that comes with DLCI 201 goes to interface Serial1 with DLCI 102 in F-R header in it.

Basically what we have done here is a PVC: Serial1:102 <---------> Serial2:201

To test this we now need two routers to connect to these serial intefaces. For instance R1 s0/0 <-----> serial 1 of FRS, and R2 s0/0 <-----> serial 2 of FRS.

We configure R1 & R2  like this (I am using physical inteface on R1 and subinteface on R2)

======================R1================================

interface serial0/0

encapsulation frame-relay

ip address 10.1.1.1 255.255.255.0

frame-relay map ip 10.1.1.2 102 broadcast //Note here that we use DLCI 102 that we tied on serial 1. See above carefully.

This means that every time R1 need to send a packet to 10.1.1.2 (IP of R2) it encapsulates the frame with DLCI 102 and sends via serial0/0

=====================R2==================================

interface serial 0/0

encapsulation frame-relay

interface serial0/0.1 point-to-point

ip address 10.1.1.2 255.255.255.0

frame-relay interface-dlci 201 //Since we are using point2point on R2 there is no need to map IP addresses on this interface

Said in other words, every IP packet that need to be forwarded via s0/0.1 needs to be encapsulated with DLCI 201 and sent via s0/0.

In your case you need to create 3 PVC to implement a full mesh F-R cloud that connects 3 Routers.

In every FRS serial interface you need two frame-relay route commands.

Hope this helps!

Regards,

Arber

Please rate helpful posts

[Renne Stuart]

why would you use point to point ? Do you need to tell it it is point to point ? I actually drew out the network with DLCI and thought I had it right but then implimented it and it seems I have totally mis understood the config ! I will try again tonight with some of the configs on here to get a full mesh frame relay network.

Thanks

[cadet alain]

Hi,

What I proposed you was a hub and spoke config not a full mesh.So if you want full mesh don't try my configs.

Regards.

Alain.

[Arber_123]

In general from what i've seen in lab scenarios the FRS is configured with full-mesh PVC so you can create any topology scenario that you want. If you need for instance hub and spoke topology just enable on routers the required DLCI. This full-mesh setup gives you the option to only configure the FRS only once and never to touch it again. To enable only the reqired DLCI as you should know disable frame-relay inverse arp (no frame-relay inverse-arp interface configuration command) and create static mapping between the IP that exist on the ends of each PVC to the specific DLCI (as explained with the frame-relay map command). For the n-routers full-mesh setup you have to create n*(n-1)/2 PVC. On each FRS interface you need (n-1) (that is PVC to every other interface) frame-relay route commands to implement this kind of topology.

Hope I am clear with this explanation.

Regards,

Arber.

[Renne Stuart]

Thanks everyone for your help i have now managed to get the full mesh working !   

Someone told me to use the "connect" command on the FRS which i did but then the edge routers lost connection ! do you have to configure the edge routers differently if you use the connect command ? my configs attached are working using the old way of doing it within each serial interface.

[cadet alain]

Hi,

do you have to configure the edge routers differently if you use the connect command ?

No it's just another way of telling the FRS how to switch the DLCIs.I f your router supports then you can use it instead of frame-relay routes statements.

Regards.

Alain.