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need to make a layer 2 network over Frame relay with Cisco

Here is the situation. I have a customer with a bunch of connections. Some of the connections are ethernet over fiber. They all bridge together and we provide a layer 2 network between the customer's various sites.

We are now adding an additional few sites. But the new sites are going to connect with Frame relay.

I have 1 frame connection at my central site ( from which the fiber goes out) and 2 other sites that connect to the cloud. In addition, one of the 2 sites has a P2P T-1 going to a third site. Ideally I would like to continue to provide a layer 2 solution. I would have to guess I can use IP un-numbered on all my routers. But then how can I manage them? ideas?

I already have 3 2511s I can use and a 1600, so I think I am set on the hardware.

picture:

POP ------ Cloud ------ site 1
|
|
site 2 ---T1-- site 3

geoffryn

Layer 2? So you want to bridge all of the sites togather? Why is a layer 2 solution the best? You will be wasting valuable WAN bandwidth on broadcast traffic.

jjeff1

ASKER

I am well aware of the waste of bandwidth. The point is that as an ISP I don't want to get involved in trying to deal with the customers IP addressing scheme.

asarluhi

You can run the frame-relay interface as part of a bridge group. Broadcasts are supported on multipoint interfaces with the frame-relay map bridge command. See the following URL for more information:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/ibm_c/bcprt1/bctb.htm#xtocid1230316

This is technically an example for IBM transparent bridging, but it basically holds for any L2 protocol. Remember to *not* configure IP addresses on the transit interfaces...

Let me know if you need more detail.

Good luck-

jjeff1

ASKER

Yes, I was looking also for some basic config.

Also, would I by able to access these devices in any way? You said I can't assign an IP to the transit ( umm, you mean the serial interfaces )so I assume not.

Les Moore

You have a couple of options:
at Site one, you can setup one interface with frame-relay encapsulation and run multiple sub-interfaces to the other sites. Each sub-interface can have it's own IP address. If you use IP unnumbered, then you can still manage the devices by connecting to whatever address you identify in the ip unnumbered statement.

Example:

Site 1 main:
Interface Serial 0/0
encap frame-relay
Int serial 0/0.1
description connected to site 2
ip add 192.168.255.1 255.255.255.252
frame-relay interface-dlci 200 {DLCI is assigned by the telco}
!
ip route <ip network of site 3> mask 192.168.255.2

Site 2

Interface Serial 0
encap frame-relay
Int serial 0.1
description connected to site 1
ip add 192.168.255.2 255.255.255.252
frame-relay interface-dlci 100 {DLCI is assigned by the telco}
!
Interface serial 1
description point-to-point to site 3
ip address 192.168.255.5 255.255.255.252
!
ip route <ip network of site 1> mask 192.168.255.1
ip route <ip network of site 3> mask 192.168.255.6

Site 3:
Interface Serial 0
description point-to-point to site 2
ip address 192.168.255.6 255.255.255.252
!
ip route 0.0.0.0 0.0.0.0 192.168.255.5

Hope this helps!

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asarluhi

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jjeff1

ASKER

Please don't lock the question. I want to get feedback from everyone.

jjeff1

ASKER

I am doing basically what asarluhi wrote. I made by serial interfaces and threw them, along with my ethernet interface into a bridge group.

Unfortunatly, the telco messed up the DLCIs, so I was unable to get anything to work.

jjeff1

ASKER

Unfortunatly, I can't make this work at all.

I have been trying to use IRB with no luck.

As soon as I put the serial sub interface into a bridge group, all the PVC info dissappears from a show frame-relay pvc

jjeff1

ASKER

Here is what I have on my core router:
!
interface ATM1/0.26 multipoint
atm pvc 36 0 128 aal5snap
bridge-group 26
!
interface Serial4/6
no ip address
encapsulation frame-relay IETF
frame-relay lmi-type ansi
!
interface Serial4/6.1 point-to-point
frame-relay interface-dlci 30
bridge-group 26
!
interface Serial4/6.2 point-to-point
frame-relay interface-dlci 31
bridge-group 26
!
interface BVI26
description gbar
no ip address
!
bridge 26 protocol ieee
bridge 26 route ip

And on the edge :

Interface serial0
no ip address
encap frame-relay ietf
frame-relay lmi-type ansi

interface serial0.1 point-to-point
frame-relay interface dlci 16
bridge group 1

bridge crb
bridge 1 protocol ieee

int ethernet0
no ip address
bridge-group 1

The edge router is running IOS 10.0 and does not have enough flash or RAM to upgrade.

I will see how this goes. I have had problems in the past, but this looks like it should all work.

Jeff

jjeff1

ASKER

This is more or less what I ended up doing. I found that one of my problems was with the old code on one of my edge routers. The BVI simply did not work on the router, once I upgraded from 10 to 11 code, all was well.