Bridge help, please

Unanswered Question
Aug 23rd, 2010

Hi,

I want to setup a transparent bridge between c805 (IOS 12.3) and c2503 (IOS 11.1).

The members of bridge would be: eth0 and serial0 interfaces.

I want to bridge IP protocol.

Is that possible?

I tried to config it without cuccess.

TIA,

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.4 (9 ratings)
Loading.
Giuseppe Larosa Mon, 08/23/2010 - 13:43

Hello Aruzsinsky,

if your setup is :

LAN --- R1 --- serial ---- serial --- R2 --- LAN

bridging over the WAN is possible even if it is not recommended

see

http://www.cisco.com/en/US/docs/ios/bridging/configuration/guide/br_transprnt_brdg_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1002811

http://www.cisco.com/en/US/tech/tk331/tk660/technologies_tech_note09186a0080094471.shtml#ex1

if you want to use IRB you will need a line telling that you want to bridge IPv4

bridge 1 irb

bridge 1 bridge ip

int e0

bridge-group 1

int s0

bridge-group 1

on both devices

use appropriate interface names

without IRB you will need to disable ip routing globally with

no ip routing

Hope to help

Giuseppe

aruzsinszky Mon, 08/23/2010 - 22:56

Hi,

LAN --- R1 --- serial ---- serial --- R2 --- LAN

Yes, this would be the situation.

irb is the only config possibility on c805. On c2503 there is just crb.

I think I did the config what you wrote from Cisco's web pages.

What do I have to do if I want to give IP address for the routers for

management purpose?

Can I ping the both routers from each other? It doesn't work for me.

without IRB you will need to disable ip routing globally with

no ip routing

I think I did, too.

TIA,

Paolo Bevilacqua Mon, 08/23/2010 - 13:47

I tried to config it without cuccess.

That is actually a good thing, because you will have nothing but troubles by bridging IP over WAN.

aruzsinszky Mon, 08/23/2010 - 23:05

That is actually a good thing, because you will have nothing but troubles by bridging IP over WAN.

OK. What can I choose if I have to connect an Ethernet device which is 8-10kms far from the local LAN

and there are 4 wire with Nokia 2Mbps modems and two retired Cisco routers.

Now I did a new subnet and a Linux PC routing between the LAN segments over PPP with a RAD mini

modem pair on 9,6kbps.

If you have any ideas, don't hesitate, write down here, please!

TIA,

aruzsinszky Tue, 08/24/2010 - 09:39

OK, you are right.

I hate Cisco's rating system. I moved the cursor over the stars checking the written ratings and I show the rating was choosen. I wasn't able to modify any more.

The first answer was more helpful than yours. Sorry.

I thought the rating is my choose. I make a mistake it is right.

100% correct answer would be for me when I can reproduce it and my config is working. As I mentioned it doesn't work for me. I can't ping the router from the other router or LAN over the serial line.

Anonimity. I've never used it on the Net. My login name is my name: aruzsinszky means Attila Ruzsinszky.

Inspite of this voting fact I very hope you will help me because I think you can if you want.

TIA,

Giuseppe Larosa Wed, 08/25/2010 - 04:21

Hello Attila,

given:

>> irb is the only config possibility on c805. On c2503 there is just crb.

my guess is that you will be able to bridge but you may miss remote control of C2503

a BVI interface can be used with IRB, the BVI number must match the bridge-group and it provides a L3 logical interface

Be aware that the C2503 is older then the other one and this explains the different features supported.

This may be disappointing but it is an aspect we face every day in networks.

In any case, consider use of IP routing if possible, as these bridging solutions have several drawbacks.

>> Anonimity. I've never used it on the Net. My login name is my name: aruzsinszky means Attila Ruzsinszky.

I put my name at the end of each post.

In another recent thread a guy has been able to use three different identities to tell me I had given a wrong answer (I had written" I may be wrong ..")

Hope to help

Giuseppe

aruzsinszky Wed, 08/25/2010 - 12:35

Hi Giuseppe,

Thanks for your answer!

In another recent thread a guy has been able to use three different identities to tell me I had given a wrong answer...

I hope I didn't hurt you with my stupid mistake with the voting system.

You gives me good answers but I don't know what is the problem in my situation. Tomorrow I'll try to setup an other config with old-old and new-new router pairs.

First question: Is possible to use bridge between my old c2503 and "new" c1601 or c805?

I think there is a mistake my hardware config: missing pingable Ethernet device which is connected to Ethernet port of the router. I just plugged in an unmanageable switch.

Second question: If I have got only two routers and a bridge between them and I use crb + no ip routing how can I ping or reach the router itself?

my guess is that you will be able to bridge but you may miss remote control of C2503

The first part of the sentence is right, I think. The second is wrong because I'm on the console on every router.

Can I put here any "sh" output? I can see some very strange (for me) MAC addresses. I switched on debugging almost all related functions and I can see spanning-tree traffic on serial port. Is that means the bridge is right? I think yes.

This may be disappointing but it is an aspect we face every day in networks.

Yes, I know this. I got some c2503 without any cost. c805 was removed from an other system because we use faster speed (2Mbps) on WAN interface.

In any case, consider use of IP routing if possible, as these bridging solutions have several drawbacks.

Now it is working with IP routing without any Cisco devices. A normal PC with Linux does the routing between ethernet and PPP. For only one Ethernet IP device I'm not too enthusiastic setting up a new IP segment. Now it is the solution and I want to change to bridge because maybe we will get a faster modem with X.21 interface what I can't connect to Linux, easily.

So I hope I can solve my problem with Cisco's bridge instead of the fact I don't like bridging very much.

TIA,

BTW: I forgot to mention: c2503 with IOS 11.1 doesn't know OSPF which is our routing protocol ... -1 point for IP routing. As usually it is solvable, because the one end of the LAN there is a c1721 and it can import EIGRP into OSPF.

Actions

This Discussion