Comments on: Ethernet over IP (L2TP) on Cisco

By: VLAN over WAN - Just just easy answers

VLAN over WAN - Just just easy answers — Fri, 06 Sep 2013 10:05:10 +0000

[…] take a look to : http://blog.dest-unreach.be/2009/05/05/ethernet-over-ip-l2tp-on-cisco http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/l2tpv325.html […]

By: Niobos

Niobos — Mon, 20 Aug 2012 16:25:44 +0000

There is no artificial limitation of speed. L2TP will go as fast as your devices can (de)encapsulate and your link can carry.
Do note, however, that protocols designed for LAN-use might suffer a lot when used over (relatively) slow internet-links. The usual example is Microsoft’s SMB/CIFS protocol.

Also, if you just want to transfer files, there is no need to set up L2TP, you can just use regular routing.

By: Brandon B

Brandon B — Mon, 20 Aug 2012 14:30:10 +0000

is there a limitation on speed? a friend and i want to setup eoip between our two 1000 base routers, there about a mile apart. we want to transfer files between our networks

By: Ethernet

Ethernet — Mon, 09 Aug 2010 08:55:03 +0000

böyle güzel bilgiler için teşekürler…

By: Niobos

Niobos — Wed, 14 Jul 2010 14:20:15 +0000

Yes, this can be used to connect switches over the internet, but please consider the security-side as well.
The two routers act like a single bridge. Technically it’s no problem to transport CDP or STP packets, but you need to take care that the routers don’t interpret the packet themselves before they’re transmitted. I haven’t tested this, and I’m not sure whether you want this.
L2TP is an IETF standard, so non-Cisco devices can implement it as well. Cisco’s feature navigator tells me that L2TP is available even on an Cisco 867, so definitely not “high end only”.

By: newbie

newbie — Tue, 13 Jul 2010 14:48:17 +0000

Can this technique be used to connect to switches over the internet ?

Can the two switches then exchange cdp / spanning tree bpdus etc ?

Also, is this only on very high end cisco platforms ?

By: Niobos

Niobos — Tue, 23 Feb 2010 21:45:55 +0000

Hi Greg,

I haven’t tried it on a VLAN or port-channel, so I can’t answer that. Technically I don’t see a problem, but it might be unimplemented…

As for the entire configuration, I’d have to re-create it myself. The only thing you need beside the posted lines is working router (having IP connectivity to the other end). I’m sure you’ll find plenty of examples in pretty much every book/website on Cisco. If you really can’t figure it out, I’ll re-create the full config and post it.

By: Greg

Greg — Tue, 23 Feb 2010 21:12:08 +0000

PS. Would you mind posting a copy of your entire config?

By: Greg

Greg — Tue, 23 Feb 2010 21:08:59 +0000

Is it just as simple to configure this on a vlan or port channel? This L2TP documentation that Cisco has is gonna make my head explode!

By: Niobos

Niobos — Tue, 18 Aug 2009 15:30:03 +0000

There is no specific WAN-interface or address. The above example will take every Ethernet frame it receives on Fa0/0 and encapsulate it in an IP packet, destined to 10.0.0.3. This IP packet will be processed just like every other IP packet.

In the example above, the packet is sent over a normal LAN via Fa0/1, but it could just as well be an IPsec VPN.

Since this whole procedure works on Ethernet frames, you don’t need to define any 802.1q parameters, nor subinterfaces. Every frame is encapsulated as-is, including a dot1Q header (if present).

Hope this clears things up a bit.