In message <NDBBJJPLIGJGLBKILFIHMEPLMIAA.ekgermann@cctec.com>, "Eric Germann" w
rites:
winders does use udp instead of icmp in their tracert program, IIRC (or at
least they used to). At the risk of getting my head blown off, could we say
that was foresight
No, they use icmp. Or at least that's what the XP box sitting next to
me does...
    --Steve Bellovin, http://www.research.att.com/~smb
So far I've seen is it uses UDP with a TTL that increments by one for
each hop. The ICMP time exceeded message is returned from the interface
of the router closest to you, and then windows tries to ping the hop. If
it can't do this, it displays * * *.
Why it needs do this rather than simply use only UDP like the rest of
the world, I don't know. But leave it to microsoft to be different...
-Paul
Date: Mon, 29 Sep 2003 16:10:59 -0400
From: Steven M. Bellovin
No, they use icmp. Or at least that's what the XP box
sitting next to me does...
AFAIK, it's been that way since Win95. I recall a certain
vendor's dodgy ISDN router * * * on Windows traceroute, but
working fine under *ix... for whatever reason, said router didn't
like the ICMP traceroute, but returned unreachables in response
to UDP when TTL expired.
Eddy
AFAIK, it's been that way since Win95. I recall a certain
vendor's dodgy ISDN router * * * on Windows traceroute, but
working fine under *ix... for whatever reason, said router didn't
like the ICMP traceroute, but returned unreachables in response
to UDP when TTL expired.
WindowsNT tracert.exe uses 92 byte icmp packets. There is a modified version
that uses a smaller sized icmp packet at
http://www.nthelp.com/NT6/tracert_broken.htm that works fine on Windows
2000.
Geo.
WindowsNT tracert.exe uses 92 byte icmp packets. There is a modified
version
that uses a smaller sized icmp packet at
http://www.nthelp.com/NT6/tracert_broken.htm that works fine on Windows
2000.
So if tracert1 doesn't work, would that mean Comcast is actually blocking
all ICMP ? I have been told they are only blocking 135-139, 4444
I get the same results with tracert and tracert1 (below)
D:\Temp>ver
Microsoft Windows 2000 [Version 5.00.2195]
D:\Temp>tracert1 www.advil.com
Tracing route to www.advil.com [164.109.5.98] over a maximum of 30 hops:
  1 20 ms 10 ms 10 ms c-24-218-168-1.ne.client2.attbi.com
[24.218.168.1]
  2 20 ms 10 ms 10 ms 24.62.0.245
  3 * * * Request timed out.
  4 * * * Request timed out.
  5 * * * Request timed out.
  6 * * * Request timed out.
  7 * * * Request timed out.
D:\Temp>tracert www.advil.com
Tracing route to www.advil.com [164.109.5.98] over a maximum of 30 hops:
  1 20 ms 10 ms 10 ms c-24-218-168-1.ne.client2.attbi.com
[24.218.168.1]
  2 10 ms 10 ms 20 ms 24.62.0.245
  3 * * * Request timed out.
  4 * * * Request timed out.
  5 * * * Request timed out.
  6 * ^C
Eric
WindowsNT tracert.exe uses 92 byte icmp packets. There is a modified
version
that uses a smaller sized icmp packet at
http://www.nthelp.com/NT6/tracert_broken.htm that works fine on Windows
2000.
So if tracert1 doesn't work, would that mean Comcast is actually blocking
all ICMP ? I have been told they are only blocking 135-139, 4444
I get the same results with tracert and tracert1 (below)
D:\Temp>ver
Microsoft Windows 2000 [Version 5.00.2195]
D:\Temp>tracert1 www.advil.com
Tracing route to www.advil.com [164.109.5.98] over a maximum of 30 hops:
  1 20 ms 10 ms 10 ms c-24-218-168-1.ne.client2.attbi.com
[24.218.168.1]
  2 20 ms 10 ms 10 ms 24.62.0.245
  3 * * * Request timed out.
  4 * * * Request timed out.
  5 * * * Request timed out.
  6 * * * Request timed out.
  7 * * * Request timed out.
D:\Temp>tracert www.advil.com
Tracing route to www.advil.com [164.109.5.98] over a maximum of 30 hops:
  1 20 ms 10 ms 10 ms c-24-218-168-1.ne.client2.attbi.com
[24.218.168.1]
  2 10 ms 10 ms 20 ms 24.62.0.245
  3 * * * Request timed out.
  4 * * * Request timed out.
  5 * * * Request timed out.
  6 * ^C
Eric
They are filtering either ICMP echo or echo reply; using an LBNL/Unix traceroute is successful the entire path.
Eric Kagan wrote:
