nanog mailing list archives

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


From: Bryan Tong <contact () nullivex com>
Date: Mon, 22 Oct 2012 16:12:06 -0600

As far as I know. There is no RFC based restrictions based on having
those as usable IPs.

We have been routing customers IP blocks on our network for a while
and never had a problem with 0 or .255 as the assigned IP even with
Microsoft Windows 2003 as the operating system.

Im not sure how to fix your issue but I dont think its automatically
disregarded by anyone that would seem silly.

On Mon, Oct 22, 2012 at 4:07 PM, Paul Zugnoni
<paul.zugnoni () jivesoftware com> wrote:
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.



-- 
--------------------
Bryan Tong
Nullivex LLC | eSited LLC
(507) 298-1624


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