[c-nsp] Bridging two VLANs together

Frank Bulk - iNAME frnkblk at iname.com
Thu Dec 20 20:43:05 EST 2007


Thanks.  Unfortunately, "bridge 2 protocol ieee" is not a valid command on
my 7609-S 12.22SR.  Without it, I don't think it's worth trying the
subinterfaces.

Regards,

Frank

-----Original Message-----
From: Collins, Richard (SNL US) [mailto:richard.1.collins.ext at nsn.com] 
Sent: Thursday, December 20, 2007 3:44 PM
To: cisco-nsp at puck.nether.net
Cc: frnkblk at iname.com
Subject: Re: [c-nsp] Bridging two VLANs together

Hello Frank,

I did get it working with my 2851.  I used subinterfaces on my Gigabit
trunk port Gi0/1.  It only worked if I used the bridge-group under these
subinterfaces and not under the int vlan.  Maybe it is similar with your
gear?  Is something similar to "bridge 2 protocol ieee" available on
your router?

Router2851#
!
bridge irb
!

!
interface GigabitEthernet0/1
 no ip address
 duplex auto
 speed auto
!
interface GigabitEthernet0/1.10
 encapsulation dot1Q 10
 bridge-group 2
 bridge-group 2 spanning-disabled  # necessary if using MST on the
uplink switch -not necessary if Rapid STP or PVST
!
interface GigabitEthernet0/1.11
 encapsulation dot1Q 11
 bridge-group 2
 bridge-group 2 spanning-disabled  # necessary if using MST on the
uplink switch -not necessary if Rapid STP or PVST

!
!
interface Vlan10  (didn't seem to work if I put the bridge-group 2 here
and on SVI Vlan11)
 no ip address
!
interface Vlan11
 no ip address

bridge 2 protocol ieee


As a side note:  A nice command to see what is going on is "show int
irb"

2851#sh int irb

GigabitEthernet0/0

 Routed protocols on GigabitEthernet0/0:
  ip

GigabitEthernet0/0.10

GigabitEthernet0/1

 Not bridging this sub-interface.

GigabitEthernet0/1.1

 Not bridging this sub-interface.

GigabitEthernet0/1.10

 Bridged protocols on GigabitEthernet0/1.10:
  appletalk  clns       decnet     ip

 Software MAC address filter on GigabitEthernet0/1.10
  Hash Len    Address      Matches  Act      Type
  0x00:  0 ffff.ffff.ffff         0 RCV Physical broadcast
  0x2A:  0 0900.2b01.0001         0 RCV DEC spanning tree
  0x68:  0 0017.59de.6c31         0 RCV Interface MAC address
  0xC0:  0 0100.0ccc.cccc         0 RCV CDP
  0xC1:  0 0100.0ccc.cccd       271 RCV SSTP MAC address
  0xC2:  0 0180.c200.0000         0 RCV IEEE spanning tree
  0xC2:  1 0180.c200.0000         0 RCV IBM spanning tree
  0xC2:  2 0100.0ccd.cdce         0 RCV VLAN Bridge STP

GigabitEthernet0/1.11

 Bridged protocols on GigabitEthernet0/1.11:
  appletalk  clns       decnet     ip

 Software MAC address filter on GigabitEthernet0/1.11
  Hash Len    Address      Matches  Act      Type
  0x00:  0 ffff.ffff.ffff      1531 RCV Physical broadcast
  0x2A:  0 0900.2b01.0001         0 RCV DEC spanning tree
  0x68:  0 0017.59de.6c31         0 RCV Interface MAC address
  0xC0:  0 0100.0ccc.cccc         0 RCV CDP
  0xC1:  0 0100.0ccc.cccd       317 RCV SSTP MAC address
  0xC2:  0 0180.c200.0000         0 RCV IEEE spanning tree
  0xC2:  1 0180.c200.0000         0 RCV IBM spanning tree
  0xC2:  2 0100.0ccd.cdce         0 RCV VLAN Bridge STP

------------------------------

Message: 6
Date: Mon, 17 Dec 2007 19:00:32 -0600
From: "Frank Bulk" <frnkblk at iname.com>
Subject: Re: [c-nsp] Bridging two VLANs together
To: <cisco-nsp at puck.nether.net>
Message-ID:

<!&!AAAAAAAAAAAuAAAAAAAAAKTyXRN5/+lGvU59a+P7CFMBAN6gY+ZG84BMpVQcAbDh1IQA
AAATbSgAABAAAAAPWVrLMU4oT5jbpE49LkZrAQAAAAA=@iname.com>

Content-Type: text/plain;       charset="us-ascii"

>I tried bridging but that didn't work.  The VLAN mapping is non-starter
>because it appears that only maps from dot1q to isl.  So I ended up
burning
>2 Ethernet ports, dropping a VLAN on each, and then using a cross-over
cable
>between the two ports.  It's not visually pretty, but it will do.

>Regards,

>Frank


-----Original Message-----
From: Collins, Richard (SNL US) [mailto:richard.1.collins.ext at nsn.com]
Sent: Friday, December 14, 2007 5:07 PM
To: cisco-nsp at puck.nether.net
Cc: frnkblk at iname.com
Subject: RE: Re: [c-nsp] Bridging two VLANs together

>Hello Frank,

>I think that I will have a chance to lab this up next week.

>I just wanted to say that the fall-back bridging is on the wrong track
>and
>it seems that only "non-routable" traffic will be bridged with
fall-back
>and not all traffic (i.e. IP).

>Maybe someone else has some more experience here.

>Rich



-----Original Message-----
From: ext Frank Bulk [mailto:frnkblk at iname.com]
Sent: Thursday, December 13, 2007 7:21 PM
To: Collins, Richard (SNL US); cisco-nsp at puck.nether.net
>Subject: RE: Re: [c-nsp] Bridging two VLANs together

>The command "bridge 2 protocol ieee" is not available in the 12.2SR
software
>release on this router.

>Bridging isn't really bridging if it's Layer-3 aware, is it? ;)

>Frank

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Collins, Richard
(SNL US)
Sent: Wednesday, December 12, 2007 4:25 PM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Bridging two VLANs together


 Hello,

If I recall correctly, fall-back bridging is only for non-ip traffic.
Though I haven't tested it I believe your configuration with the
addition
of "bridge 2 protocol ieee" should work.

Rich

>I believe what you propose (fall-back bridging) will "work",
>but will be performed in software.

>Yuck.

>Dale


>On Dec 12, 2007, at 2:58 PM, Frank Bulk wrote:

> Protocol 'ieee' is not an option, but 'vlan-bridge' is.  I've
> applied it to
> the global config.
>
> Anything in:
> http://puck.nether.net/pipermail/cisco-nsp/2005-May/020444.html
> that would suggest this is not enough?
>
> Frank
>
> -----Original Message-----
> From: Masood Ahmad Shah [mailto:masood at nexlinx.net.pk]
> Sent: Wednesday, December 12, 2007 10:54 AM
> To: frnkblk at iname.com; cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] Bridging two VLANs together
>
> Well, If I understand you are talking about inter-vlan bridging.
> Yes it
> should work fine. You may need to add
>
> bridge 2 protocol ieee
>
> It's bridge protocol global configuration command to define the
> type fo STP.
>
>
> Regards,
> Masood Ahmad Shah
>
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Frank Bulk
> Sent: Wednesday, December 12, 2007 9:15 PM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] Bridging two VLANs together
>
> We have a unique situation where our transport equipment can't
> bridge the
> traffic between two endpoints, so we would like to dump off each
> link's VLAN
> onto our router (7609-S with WS-X6748-GE-TX blades) where it can
> perform the
> bridging. Any reason why the following configuration wouldn't work?
>
> interface GigabitEthernet1/31
>  description Customer networks
>  switchport
>  switchport trunk encapsulation dot1q
>  switchport trunk allowed vlan 221-222
>  switchport mode trunk
> end
>
> interface Vlan221
>  description Site 1
>  no ip address
>  bridge-group 2
>  bridge-group 2 spanning-disabled
> !
> interface Vlan222
>  description Site 2
>  no ip address
>  bridge-group 2
>  bridge-group 2 spanning-disabled
> !
>
> Some of you might ask why not put the endpoints in the same VLAN,
> but the
> endpoints don't maintain an MAC address table so there's nothing to
> make
> them exchange traffic with each other.
>
> Regards,
>
> Frank
>



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