On Fri, 3 Jan 2003, jamal wrote:

Too many emails to respond to at once.

Q: Is this a hack?
A: Yes, indeed it is. wrong API is the main culprit.

Q: Is this a feature needed by only a few people?
A: No, Absolutely not. RFC2338 is one example that needs

The common way of handling this is unsolicited ARP.

How common are NICS such as the 21x4x that can be programmed to do
perfect hashing and accept multiple MAC addresses in hardware?

Not very common.  I mentioned the 21*4* explicitly because few other
common chips implement this feature.
The Digital design implemented it because of DECnet, which is long dead.

And if this was a commodity feature - what happens to PACKET_HOST
setting? an netdevice can only have one unicast MAC address.
SIOCDEVPRIVATE does not seem to be the right place to do this.
You still wanna have ability to do proper RFC2338 and related protocols
even when the h/ware is incapable.
And btw, i didnt even open up the whole can of worms - we also need to
respond back with proper MAC addresses to ARPs and packets sourced with
specific virtual router IPs. This is a seprate problem.

Yup, a whole can of worms if you want it to be a general feature handled
by the kernel...

PS: the hack credit (for using SIOCADDMULTI/DELMULTI) goes to Jerome
Ettiene (this is a guy who never responds to email, probably too busy
unicycling somewhere, so no point in ccing him) - Except it doesnt work
without the patch i posted.

This has worked with the Tulip driver for many years.  I've pointed it
out to a number of people that requested this as a new feature.


-- 
Donald Becker				becker@scyld.com
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