CCNA 55

Right now I'm going to walk through the configuration of a Frame Relay network using both multi-point and point-to-point configurations. For this article, I'll be using this topology:

First of all, back on R1, set the IP and change the serial interface encapsulation to Frame Relay:
ip add 192.169.1.1 255.255.255.0
encap frame
no shut

Now, if you're on an older router, you'll need to manually configure the LMI type:
frame lmi-type cisco

To see LMI information, use:
show frame-relay lmi

To see the PVCs connected, use:
show frame-relay pvc

In a multi-point configuration, you'll have to use the frame-relay map command. To do this, type:
frame map ip 192.169.1.2 102 broadcast
frame map ip 192.169.1.3 103 broadcast
frame map ip 192.169.1.4 104 broadcast

The broadcast means that any broadcast traffic should be forwarded to R2 as a unicast packet. Frame Relay is a NBMA network, so broadcast traffic are blocked.

You can list Frame Relay maps like this:
show frame map

There are three status that maps can be in:
Inactive - Local is set up, remote is down
Active - Local and remote are both set up
Deleted - Invalid DLCI number

Right now the configuration should be:
R1
ip add 192.169.1.1 255.255.255.0
encap frame
frame map ip 192.169.1.2 102
frame map ip 192.169.1.3 103
frame map ip 192.169.1.4 104
no shut
R2
ip add 192.169.1.2 255.255.255.0
encap frame
frame map ip 192.169.1.1 201
no shut
R3
ip add 192.169.1.3 255.255.255.0
encap frame
frame map ip 192.169.1.1 301
no shut
R4
ip add 192.169.1.4 255.255.255.0
encap frame
frame map ip 192.169.1.1 401
no shut

Right now the spokes can ping the hub but cannot ping each other. To fix this, you'll have to map all the other spokes using the same DLCI that points to the hub. For example, back on R2, I'll type this:
frame map ip 192.169.1.3 201 br
frame map ip 192.169.1.4 201 br

After doing this, you should be able to ping everyone from everywhere. This, however, causes problems with split horizon where only the hub would have all the routes.

Right now I'll clear the configurations on the interface, and replace them with point-to-point. To do this, use:
default int s0/0

Then on R1, I'll use the following configuration:
in s0/0
encap frame
no shut
in s0/0.2 point-to-point
frame int 102
ip add 192.169.1.1 255.255.255.0
in s0/0.3 point-to-point
frame int 103
ip add 192.169.2.1 255.255.255.0
in s0/0.4 point-to-point
frame int 104
ip add 192.169.3.1 255.255.255.0

Then on R2, do this:
in s0/0
encap frame
no shut
in s0/0.1 point-to-point
frame int 201
ip add 192.169.1.2 255.255.255.0

On R3, do this:
in s0/0
encap frame
no shut
in s0/0.1 point-to-point
frame int 301
ip add 192.169.2.2 255.255.255.0

Finally, on R4, do this:
in s0/0
encap frame
no shut
in s0/0.1 point-to-point
frame int 401
ip add 192.169.3.2 255.255.255.0

From here, a routing protocol should be able to bring the routing up automatically. There will be no split horizon problems.