2009/304 IP PROMISC Flag

[James Carlson]

Sebastien Roy writes:
> therefore shouldn't show up in ifconfig output.  The more correct place
> to show whether or not a given datalink has had DL_PROMISC_PHYS enabled
> would be in dladm output, perhaps through a read-only link property.

Sure; feel free to include it there if you want.  The point of this
project is that not only do all of the other OSes include IFF_PROMISC
and a "PROMISC" flag, but that *we* actually have them as well
(because we inherited them from BSD), but they're just sitting around
dormant.  This project kicks them back to life.

(And, if I recall correctly, SunOS 4.x _also_ included this flag.  We
just broke it in Solaris.)

> Administrators don't really know or care about the "phyint_flags" member
> of struct phyint in the kernel.

Indeed.

>  What they do care about is the meaning
> of PROMISC flag when they see it in the ifconfig output.  You'll likely
> need to specify something more administratively meaningful in the
> ifconfig man page anyway, could that verbiage be specified in this case
> please?

"The interface is in promiscuous mode."

What "promiscuous" actually means is likely highly dependent on the
actual hardware in use, and probably can't be fully explained.  (Many
of those old BSD interfaces seem to have been designed with Ethernet
alone in mind, where the meaning for this sort of flag is obvious.)

> Does the flag have any semantics on IPMP interfaces?

No.  No virtual or IP-only interfaces have this flag.

> What about lo0; should it ever appear there?

I wouldn't expect it.

> (the last two questions relate to my grumblings about this having little
> to do with IP interfaces)

Agreed.  But sometimes you have to go with the crowd.

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
Sun Microsystems / 35 Network Drive        71.232W   Vox +1 781 442 2084
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