Point to Point Ethernet

Andre Oppermann nanog-list at nrg4u.com
Wed Jul 8 17:12:52 UTC 2009

On 08.07.2009 18:04, Joe Greco wrote:
>> More importantly one can specify the just the outgoing interface
>> again instead of the next hop:
>>    ip route g0/1
>> Do you think this is useful?  Maybe vendors will hear me/us.
> No.  What makes Ethernet useful and successful is that, unlike most
> other network/interconnection technologies, it is cheap and plentiful,
> out of necessity.  Any time you have something that is high volume,
> demand creates pressure to produce more cheaply, and costs slide as
> volumes spike.
> There are absolutely "better" choices for point to point circuits,
> and there are certainly ways to make a point to point version of
> Ethernet, but doing so invariably seems to involve a lot of reworking
> of the underlying mechanisms, which means that you've just invented a
> way to make your special-case Ethernet ... expensive.
> Anything that can be done exclusively in software, without modifying
> the silicon, is probably the only practical way to accomplish this.
> However, then you're still leaving more cans of worms to open, because
> then there'll be someone who wants to be able to do "something like"
> this but have vlan support so they can break out an expensive Foundry
> port on inexpensive switches and still do your new point to point
> protocol, etc.

This shouldn't require any hardware change.  The PHY doesn't care at
all and the MAC (Media Access Controller) can be told to ignore the
DST MAC address and pass up any packet.  So it ends up being only a
software change.  That is disabling the ARP lookup and the L3->L2
mapping table.

I'm not attached to losing the ethernet header as long as a fixed MAC
address as destination can be put there and every such incoming packet
is accepted.


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