nanog mailing list archives

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


From: Mark Andrews <marka () isc org>
Date: Tue, 23 Oct 2012 10:19:11 +1100


In message <201210222307.q9MN7AIv063740 () aurora sol net>, Joe Greco writes:
d 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 N
=
AT pool, or subnets larger than /24). Yet I've run into a commercial IP mgm
=
t product and getting reports of M$ ISA proxy that is specifically blocking
=
 traffic for an IP ending in .0 or .255.

To make a long story short:

If it's a product you're considering buying, problems with .0 and .255
reflect on the competence of the product's designers.  You can safely
assume that there are many other Severely Broken Things too and move on
to saner products.

For general Internet use, there is a lot of gear out there that's ten or
more years old.  You should avoid using .0 and .255 addresses if you can
avoid it, though it's a shame to waste valid IP space to accommodate the
brokenness of someone else's stuff.

Ten year old equipment should be CIDR aware.  It's not like it CIDR
wasn't in wide spread using in 2002.

Some of us park stuff on .0 and .255 addresses in order to motivate 
others to change.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CN
N)
With 24 million small businesses in the US alone, that's way too many apples.

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org


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