ICMP Blocking Woes

Tue Sep 30 12:31:28 UTC 2003

They are filtering either ICMP echo or echo reply; using an LBNL/Unix 
traceroute is successful the entire path.

Eric Kagan wrote:

>>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
> 