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Community Member

Layer 2 connection between distant 1841's

I have two 1841's connect to the Internet via DSL;

fa0/0 --- 1841-R1 --- DSL1 ---------------------[INTERNET]--------------------- DSL1 --- 1841-R2 --- fa0/0

I am on the LAN attached to fa0/0 on R1 and I need layer 2 connectivity to a device on fa0/0 on R2. I'm not sure if this is possible with 1841's or not? I made a GRE tunnel between the two and was going to add a BVI and bridge the tunnel at each end with fa0/0 at eah end, but the 1841's don't support BVIs so I'm a bit stumped here! Would L2TP work here?

R2 is a remote router running C1841-SPSERVICESK9-M. R1 is local running C1841-ADVENTERPRISEK9-M. I can't change the remote router so if the answer is not support in C1841-SPSERVICESK9-M I won't be able to do this.

Many thanks.

Hall of Fame Super Silver

Re: Layer 2 connection between distant 1841's

Hello Jwbensley,

L2TPv3 may be a possible solution but be aware that broadcast, unknown unicast and multicast traffic will use the WAN bandwidth and with DSL links your upstreams are not so fast.


You can use the feature navigator at

to check if the C1841 SPservices supports L2TPv3

you can use search by feature , you type L2TPv3 on the left then you check filter and all features related to L2PTv3 are showed take the voice L2TPv3 and click on add to have it added to the right column.  You then click on continue on the far right.

The display changes and you can select the OS, you select IOS and then the plaftform C1841 and you will see SP services listed as supporting image.

Hope to help


Community Member

Layer 2 connection between distant 1841's


Yes, you are right. C1841-SPSERVICESK9-M does not support IPsec VPN. You need to upgrade the IOS image. Please check the below link.



Hall of Fame Super Gold

Layer 2 connection between distant 1841's

And why you think you need L2 connectivity ?

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