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

Scott Weeks surfer at mauigateway.com
Mon Oct 22 22:57:18 UTC 2012


--- job at instituut.net wrote:
From: Job Snijders <job at instituut.net>

> 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.



I used about a /15s worth of /23s for DHCP at a previous employer for 5 years 
(2005 - 2010) and they're still using them today years later.  Never got one 
complaint AFAIK.  I even got one of the .0 or .255 addresses for a while and
never had trouble.  This was discussed in detail a while back.  Look in the 
archives.

scott



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