uBR 7246 bridging?

[Smailmilak83_2]

Hi,

I have a question.

How can I solve my problem on the picture?

Is it possible that the default GW is the internet router and the CMTS is acting as a bridge?

[paolo bevilacqua]

And why should you bridge ?

[Smailmilak83_2]

As you can see the whole subnet (/24) is on the internet router. It is not possible to subnet it.

It is a production network and I can not change anything.

[jbyrne]

Hi,

Did you ever get this figured out?

I'm in exactly the same boat now myself.

Any help you could offer would be greatly appreciated.

Many thanks,

John

[smailmilak]

Hi,

bridging is definately not supported.

Our customer deceided to use DHCP only, and I think this is a better solution than PPPoE.

But you can use the uBR as LAC if you want PPPoE.

Here is an example:

https://supportforums.cisco.com/docs/DOC-6101

[jbyrne]

Hi and Thanks for getting back to me.

I'm migrating from Arris C3 CMTSs to the uBR7246 platform.

On a simplified level, our current network config has Business User Cable Modems using one Config file while Residential User use another Config file.

For the Arris C3 CMTS, I just specify which Cable SubInterface to attach CPE traffic TO in the Modem Config File, and I have this Cable SubInterface in the same Bridge-group as a FastEthernet SubInterface which has an associated VLAN Tag.

This results in the Traffic Passing through the CMTS and appearing on the other end as Tagged Traffic.

I need to be able to Separate Business Customer Traffic from Residential Customer Traffic and in addition to this, I do have a few Customers that would use PPPoE in their own Private VLAN.

What you suggest above might work for the PPPoE Customers, but are you saying that that I can't separate the other customer traffic into Business and Residential VLANs?

There are various 'Bridge' commands in the uBR.

If not for Bridging Interfaces for Traffic, what do they do???

Router(config)#bridge ?

  <1-255>            Bridge Group number for Bridging.

  cmf                Constrained multicast flooding

  crb                Concurrent routing and bridging

  irb                Integrated routing and bridging

  mac-address-table  MAC-address table configuration commands

Router(config)#bridge 1 ?

  acquire                   Dynamically learn new, unconfigured stations

  address                   Block or forward a particular Ethernet address

  aging-time                Set forwarding entry aging time

  bitswap-layer3-addresses  Bitswap embedded layer 3 MAC adddresses

  bridge                    Specify a protocol to be bridged in this bridge group

  circuit-group             Circuit-group

  domain                    Establish multiple bridging domains

  forward-time              Set forwarding delay time

  hello-time                Set interval between HELLOs

  lat-service-filtering     Perform LAT service filtering

  max-age                   Maximum allowed message age of received Hello BPDUs

  priority                  Set bridge priority

  protocol                  Specify spanning tree protocol

  route                     Specify a protocol to be routed in this bridge group

  subscriber-policy         Subscriber group bridging

I'm using IOS v12.2(33)SCE.

Many Thanks for your time,

John

[smailmilak]

Hi,

first I have to say that I am not an uBR professional, I only configured two uBRs, one 7246 and one 10012. Both had a more or less straightforward configuration.

The first thing that comes in my mind are two Bundle interfaces, one for Business and one for Residential customers.

I tried to bridge the interfaces facing the CMs and I got an error message, later I read that the 7246 does not support it.

Maybe you can bridge between Ethernet interface, but you don't need that.

[jbyrne]

Thanks Smailmilak,

Looks like I'm going to have to redesign my network to Route CM CPE traffic if I want to use the uBR Platform.

Seems like a silly limitation to have, but I guess that's just Cisco for you.

Thanks again for your time and help.

John