On Fri, 3 Jan 2003, jamal wrote:
> Subject: SIOCADDMULTI for unicast broken
> Some programs require ability to accept packets destined to certain
> MAC addresses (in addition to their own).
> Example Jerome Ettienes vrrpd (http://w3.arobas.net/~jetienne/vrrpd/)
> The trick is to add unicast addresses via SIOCADDMULTI and accept those
> packets when they make their way up the stack.
> I think this used to work, no? Donald, any history/comments behind
This is a very specialized requirement, so specialized that it should
not be added as general-purpose requirement for drivers or the network
This capability was supported as a special case for the Tulip driver,
and then only for the real 21*4* chips that had the hardware CAM capable
of matching up to 16 destination addresses.
A few other chips support matching unicast addresses with the multicast
filter, but there is the general problem of false-accepts and
chip-specific quirks that must be dealt with.
Once again: this is a very specialized thing. Of the few people that
think they need the capability, most are wrong.
Donald Becker becker@xxxxxxxxx
Scyld Computing Corporation http://www.scyld.com
410 Severn Ave. Suite 210 Scyld Beowulf cluster system
Annapolis MD 21403 410-990-9993