Issues encountered with assigning .0 and .255 as usable addresses?

[Paul Zugnoni <paul.zugnoni () jivesoftware com>]

Curious whether it's commonplace to find systems that automatically regard .0 and .255 IP addresses (ipv4) as src/dst 
in packets as traffic that should be considered invalid. When you have a pool of assignable addresses, you should 
expect to see x.x.x.0 and x.x.x.255 in passing traffic (ie. VIP or NAT pool, or subnets larger than /24). Yet I've run 
into a commercial IP mgmt product and getting reports of M$ ISA proxy that is specifically blocking traffic for an IP 
ending in .0 or .255.

Any experience or recommendations? Besides replace the ISA proxy…. Since it's not mine to replace. Also curious whether 
there's an RFC recommending against the use of .0 or .255 addresses for this reason.