The use of .0/.255 addresses.

Jared Mauch jared at puck.nether.net
Sun Jun 27 01:33:54 UTC 2004


On Sat, Jun 26, 2004 at 05:01:14PM -0700, Tony Li wrote:
> >Various people I've asked about this have said they wouldn't use the .0
> >or .255 addresses themselves, though couldn't present any concrete info
> >about why not; my experience above would seem to suggest a reason not 
> >to
> >use them.
> 
> The .255 address is very likely to be a broadcast address from a
> netblock of /24 or longer.  I would suspect that folks are wary of 
> accepting
> packets from a broadcast address as that could easily be a smurf.
> The .0 address was used as a broadcast address long ago and then
> was deprecated, so the same rationale probably applies.

	Some networks use /31s on p2p links, including peering links
to other providers.. :)

	This means those links can have a .0 or .255 IP.

	This topic has been rehashed a few times in the past (you
can find it in the nanog archives..) people using a /23
and .0 and .255 in dial and dhcp (dsl) pools having problems
due to b0rken networks/hosts.

	My suggestion: get them to clean their act up.

	This includes Washington state host software vendors that
may need to distribute patches for networking stacks with defects
in their handling of outbound TCP connections (referenced in an alternate
email..)

	- jared

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.



More information about the NANOG mailing list