From: Stephen Hemminger <redacted>
Date: Tue, 20 Mar 2007 14:17:09 -0700

Instead of hashing the whole Ethernet address, it should be faster
to just use the last 4 bytes. Add a random salt value to the hash
to make it more difficult to construct worst case DoS hash chains.

Signed-off-by: Stephen Hemminger <redacted>

Applied to net-2.6.22