Subject: RFC 3378 Tunneling Ethernet Frames in IP Datagrams
To: None <>
From: Patrick Mackey <>
List: netbsd-users
Date: 12/10/2003 11:09:26

I am looking at implementing a bridge between two networks and tunneling
Ethernet frames over IP.

(Ethernet) ---- NetBSD ----- (IP) ----- NetBSD ---- (Ethernet)

It looks like this might be possible with OpenBSD (see below) but
(obviously) I would prefer to use NetBSD.

From the gif(4) OpenBSD man page:

 Finally, the gif interface may be used as a bridge(4) member.  Ethernet
 frames forwarded by the bridge to the gif interface are encapsulated in-
 side an IPv4 or IPv6 header (depending on how the interface is config-
 ured), with transport protocol number 97 (etherip).  IPv4 or IPv6 packets
 carrying transport protocol 97 are delivered to the gif interface whose
 "physical" addresses match the source/destination addresses of the packet
 (the source address of the packet must match the destination "physical"
 address, and vice versa).

Unfortunately it seems that the bridge and gif counterparts in NetBSD are
more limited in this respect.

So my questions are:

Has anyone tried anything like this before?

Are there any plans for Ethernet encapsulation in IP for NetBSD?

Or is it already there and I have missed it completely?

Is this sort of thing better done in userland?

Of course I am probably trying to drive a tack with a sledgehammer...

Best Regards,
Patrick Mackey

    "You can't take the sky from me"