nanog mailing list archives

Re: traffic filtering


From: "J.F. Noonan" <jfn () msc com>
Date: Tue, 22 Jan 2002 13:57:07 -0600 (CST)



On Tue, 22 Jan 2002 at 12:34pm Joe Abley wrote:


On Mon, Jan 21, 2002 at 05:53:16PM -0500, Stephen Griffin wrote:
I'm curious about how many networks completely filter all traffic to
any ip address ending in either ".0" or ".255".

I heard recently that Windows 2000 will refuse to send packets
to addresses with the least-significant octet 255, if the most-
significant octet indicates the address lies in a pre-CIDR class
C. So, for example, 192.168.0.255 would be unreachable from a
windows 2000 machine, regardless of the fact that it might be
a legitimate host numbered within 192.168.0.0/23.


Not true.  M$ is guilty of many evil things, but not this one.



--

Joseph F. Noonan
Rigaku/MSC Inc.
jfn () msc com


-------------------------------------------

Microsoft Windows 2000 [Version 5.00.2195]
(C) Copyright 1985-2000 Microsoft Corp.

C:\>tracert o2

Tracing route to o2.msc.com [12.110.0.218]
over a maximum of 30 hops:

  1   <10 ms   <10 ms   <10 ms  netb.msc.com [192.246.38.10]
  2   <10 ms   <10 ms   <10 ms  172.16.16.2
  3   <10 ms    10 ms   <10 ms  12.124.26.249
  4   <10 ms    10 ms   <10 ms  gbr2-p51.hs1tx.ip.att.net [12.123.134.18]
  5   <10 ms   <10 ms    10 ms  gbr3-p40.dlstx.ip.att.net [12.122.2.97]
  6    10 ms    10 ms    10 ms  gbr4-p60.dlstx.ip.att.net [12.122.1.138]
  7    30 ms    30 ms    30 ms  gbr4-p50.dvmco.ip.att.net [12.122.2.102]
  8    30 ms    30 ms    30 ms  gbr1-p20.dvmco.ip.att.net [12.122.5.22]
  9    40 ms    40 ms    40 ms  ar1-p3110.slkut.ip.att.net [12.123.207.5]
 10    40 ms    40 ms    40 ms  12.127.107.26
 11    50 ms    40 ms    60 ms  fw-utah.msc.com [12.110.0.130]
 12    40 ms    40 ms    60 ms  o2.msc.com [12.110.0.218]

Trace complete.

C:\>






Current thread: