Solved: Configure Bridge mode on Cisco router for SDSL

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jonperry2

Configure Bridge mode on Cisco router for SDSL

I'm configuring a SDSL Cisco 888 router that needs to become a modem bridge for the linux firewall. Do I need to configure any connection details on the router? I Have attached a script which doesn't seem to work!

service password-encryption
hostname xxxxx
enable secret xxxx
enable password xxxxx
line con 0
password xxxx
line vty 0 4
password xxxxx
no ip domain lookup
username xxxx privilege 15 password XXXX
interface ATM0
no ip address
no atm ilmi-keepalive
pvc 8/35
encapsulation aal5snap
dsl operating-mode auto
bridge-group 1
interface Vlan1
no ip address
bridge-group 1
bridge 1 protocol ieee
int f0
no shut
int f1
no shut
int f2
no shut
int f3
no shut
banner motd #

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John Meggers🇺🇸

What version of code are you running?

jonperry2

ASKER

12.4

John Meggers🇺🇸

What interfaces connect to what? Is it only the Ethernet interfaces in use, or ATM on one side and Ethernet on the other?

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John Meggers🇺🇸

I think you're on the right track, but I admit I'm kind of shooting in the dark here. (It's been a long time since I did bridging.) Most everything I see about bridging in the documentation refers to the wireless functionality. Do you have a BVI interface configured? I also think you probably need to explicitly assign physical interfaces to the bridge group. It looks like you're assuming all switch ports are in VLAN 1 and are therefore part of bridge-group 1. HTH,,,,

jonperry2

ASKER

Thanks, it appears I can't assign Fasteth0 to the bridge group though with this IOS. Which might be a issue seeing as that's what the router attaches to... I've added VLAN 1 to the bridge which I hope sorts this issue. With the BVI interfaces do these need to be specified for all bridges?

John Meggers🇺🇸

The BVI is the logical interface that allows you to assign an IP address but you may not need that for straight-through bridging. I know you need it if you're trying to do Integrated Routing and Bridging (IRB) that allows you to route between bridge groups. I'm surprised you can't add FE0 to the bridge group, can you add any of the other interfaces or do they all behave the same?

Unfortunately I don't see anything in the config guides I've been able to find that replicates your situation, and I don't have access to an 888 to play with it myself. If you don't have TAC support and can open a case on it, the next best thing I can suggest is to try the Cisco support forums on CCO at supportforums.cisco.com.

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jonperry2

ASKER

Yep alas all interfaces FE0-3 say they do not support bridging mode. seriously find it hard to believe that I can't make bridge mode happen on a £400 router the rest of the os seems to support this though just these key interfaces. Do you think the VLAN 1 being added to the bridging group will make these interfaces work.

John Meggers🇺🇸

I really don't know for sure. Is there a reason it *must* bridge instead of route? I realize that probably seems like an easier configuration, but maybe not.

jonperry2

ASKER

No reasoin I guess for it not to router instead of bridge - anything to get it working really!

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John Meggers🇺🇸

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jonperry2

ASKER

Thanks for the help as I took your advice and moved away from the bridge method and used nat instead. Would love to know why cisco make it so hard to configure seemingly straight forward configurations in comparison to other vendors.

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