TLS on 7246UBR

Unanswered Question
Sep 18th, 2009

Hi Gurus,

Im testing the Transparent LAN service over cable, and i found out that you can only create one vlan per mac-address(cpe), is there a way wherein i can put multiple modems/mac-address on a single vlan?

tia.

Jeff

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Giuseppe Larosa Sat, 09/19/2009 - 11:58

Hello Jeff,

in 7225VXR config guide Cisco declares to follow the following standard

http://www.cablemodem.com/downloads/specs/CM-SP-L2VPN-I03-061222.pdf

at page 17 of the standard specification it says that implementations may implement a point-to-point L2VPN or a point to multipoint L2VPN but it is not a must.

Cisco implementation looks like to be only point-to-point

http://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_l2vpn.html#wp1056965

Restrictions section it is said:

Multipoint L2VPN is not supported, and any SNMP MIBs for multipoint L2VPN are not supported.

So I'm afraid that only by using an external device that makes inter-vlan bridging you can emulate an multipoint service as suggested in the standard specifications

"An external L2VPN Bridge on the cable operator's backbone actually performs the layer

2 MAC address learning for each L2VPN, and bridges packets between the VLAN IDs or pseudo-wires of

the packets within their NSI Encapsulation."

you need a Cisco 6500 to be able to perform inter-vlan bridging and routing of IPv4 traffic lower end devices support it only for non IPv4 traffic (fallback bridging)

Hope to help

Giuseppe

jeffersoncbriones Sat, 09/19/2009 - 18:56

Hi Guiseppe,

The purpose of this is to link clients using cable modem to a network using metro-e. So these means that i can only use one modem on the CMTS side. Thank you for these information.

Also,do i need to enable IRB on my UBR?

Helpful as always.

Jeff

Giuseppe Larosa Sun, 09/20/2009 - 01:06

Hello Jeff,

>> The purpose of this is to link clients using cable modem to a network using metro-e. So these means that i can only use one modem on the CMTS side

cool

>> Also,do i need to enable IRB on my UBR?

I suppose you don't need it.

You can achieve redundancy by using two vlans towards metroE provider so you can have two CE cable modem routers.

you then pass both vlans to metroE sp and you should be fine.

Hope to help

Giuseppe

jeffersoncbriones Mon, 09/21/2009 - 01:55

Hi Guiseppe,

Prior to this message i was able to make the thing work, ill try to remove this when i get back at the office. Im thinking of using the other 3 GE interface linking to the metro-e so i can map each mac-address to the vlan, so i can achieve at least 3 CM with one vlan.

Also, i tried creating sub-int for encapsulation per vlan, wouldnt work since its already binded to the main interface.

Thanks a lot for these info.

Jeff

mhz@ripnet.com Mon, 04/26/2010 - 10:46

Just wondering if you happen to have an example CM file to assign a CM to a 802.1Q VLAN ID on a 7246VXR? ... I have been searching and searching for one but no luck yet.  Would be much appreciated.

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