Re: The use of .0/.255 addresses.

[Jonathan McDowell <noodles () earth li>]

On Sat, Jun 26, 2004 at 07:41:17PM -0400, Chris Ranch wrote:
> 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.

It's from a /24 assignment, but is actually being used for tunnel
endpoints, so there seemed to be no reason not to use the .0 address.

> 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...

I spent a long time looking for each filters, and watching traffic leave
our network but not receiving any replies, while traceroutes would work
just fine.

As Peter points out, it's from what would have been Class C space, so it
looks like I'm getting bitten by the Windows stuff. All 3 sites I
mentioned as not being accessible are running under Windows according to
Netcraft.

J.

-- 
Revd. Jonathan McDowell, ULC | I don't know. I'm a dog.