I thought openbsd's CARP could do this and was in pkgsrc.
http://www.openbsd.org/faq/faq6.html#CARP
ftp://ftp.netbsd.org/pub/NetBSD/packages/pkgsrc/net/ucarp/README.html
http://www.ucarp.org/

Although CARP is normally used for failover between servers, I don't
see why it couldn't be used between nics on a single host.  If not,
Bonding (linux-esque)/IP MultiPathing (solaris-esque) functionality
has always seemed a bit lacking in netbsd.

_Matt

On 12/7/05, der Mouse <mouse@rodents.montreal.qc.ca> wrote:
> $DAYJOB has a desire to use multiple network interfaces on a single
> machine, with parallel connections to another device, as if they were a
> single interface with a fatter pipe to the peer device - I believe
> cisco calls this "connection bonding".
>
> Is there any support for this in NetBSD?  There wasn't last time I
> looked/asked, but that was years ago.  (I started on implementing it
> but got stalled practically immediately.)  I did some poking around but
> failed to turn up anything the least bit encouraging.
>
> The hard part, I'd guess, would be getting the same MAC address on all
> the underlying interfaces.  Is there any generic way implemented yet to
> set an interface's MAC address?  I did some searching with man -k, but
> didn't turn up anything there either.
>
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