[71952] in North American Network Operators' Group
RE: The use of .0/.255 addresses.
daemon@ATHENA.MIT.EDU (Chris Ranch)
Sat Jun 26 19:42:21 2004
From: Chris Ranch <CRanch@Affinity.com>
To: 'Jonathan McDowell' <noodles@earth.li>, nanog@nanog.org
Date: Sat, 26 Jun 2004 19:41:17 -0400
Errors-To: owner-nanog-outgoing@merit.edu
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I see traffic from this last IP address octet all the time from prefixes of
length less than /24. Use of these host id's when the prefix length is
greater than or equal to /24 is illegal. So if that's your case, I'd
suggest not doing it.
If that's not the case, look for over-zealous or incorrect filters in the
path. I saw this situation once before. There was a border ingress filter
with a typo in it...
Chris
> 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.
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<TITLE>RE: The use of .0/.255 addresses.</TITLE>
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<P><FONT SIZE=3D2>I see traffic from this last IP address octet all the =
time from prefixes of length less than /24. Use of these host =
id's when the prefix length is greater than or equal to /24 is =
illegal. So if that's your case, I'd suggest not doing =
it.</FONT></P>
<P><FONT SIZE=3D2>If that's not the case, look for over-zealous or =
incorrect filters in the path. I saw this situation once =
before. There was a border ingress filter with a typo in =
it...</FONT></P>
<P><FONT SIZE=3D2>Chris</FONT>
</P>
<P><FONT SIZE=3D2>> Various people I've asked about this have said =
they wouldn't </FONT>
<BR><FONT SIZE=3D2>> use the .0</FONT>
<BR><FONT SIZE=3D2>> or .255 addresses themselves, though couldn't =
present any </FONT>
<BR><FONT SIZE=3D2>> concrete info</FONT>
<BR><FONT SIZE=3D2>> about why not; my experience above would seem =
to suggest a </FONT>
<BR><FONT SIZE=3D2>> reason not to</FONT>
<BR><FONT SIZE=3D2>> use them.</FONT>
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