said by trog:Might this be related to the XP parameter UseZeroBroadcast
Documentation on this states:
UseZeroBroadcast
Key: Tcpip\Parameters\Interfaces\ID for Adapter
Value Type: REG_DWORD - Boolean
Valid Range: 0 or 1 (False or True)
Default: 0 (False)
Description: If this parameter is set to 1 (True), the IP will use zeros-broadcasts (0.0.0.0) instead of ones-broadcasts (255.255.255.255). Most computers use ones-broadcasts, but some computers that are derived from BSD implementations use zeros-broadcasts. Computers that use different broadcasts do not interoperate well on the same network.
Peter
A good guess, but I think that's for very (repeat: VERY) old network configurations where broadcast traffic used to be sent across an all-zero address (e.g. x.x.x.0/24) instead of an all-ones address (e.g. x.x.x.255/24).
For comparison, I believe on Lucent/Livingston Portmasters, this is referred to as having a "high" (all ones) or "low" (zero) broadcast address. The default is "low", but the Portmaster does this out of paranoia/concern for very old OSes, where the broadcast was all zeros. On all of my Portmasters, I have to do a `set ether0 broadcast high` for broadcast traffic to work. Cross-reference:
»
www.stat.ufl.edu/system/man/port···.fm.html--
Making life hard for others since 1977. 
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