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Re: simple question as always..

  • From: Danny McPherson
  • Date: Mon Mar 09 20:48:20 1998 
> could someone explain to me why I can ping but traceroute
> seems to have problem reaching it.

The combination of a firewall (permitting ICMP echo replies/requests, but 
filtering your UDP traceroute probes) .. and a traceroute client that doesn't 
correctly handle (IMO) the response (ICMP Type 3, Code 13: Communication 
Administratively Prohibited).

Many traceroute clients (i.e. ftp://ftp.ee.lbl.gov/traceroute.tar.Z) better 
indicate things of this nature:

[email protected]% traceroute auth3.ipass.com
traceroute: Warning: Multiple interfaces found; using 204.74.125.252 @ eb0
traceroute to ren.iPass.COM (167.216.128.232), 30 hops max, 40 byte packets
 1  fe0-2.hopper.genuity.net (207.240.3.254)  0.883 ms  0.728 ms  2.731 ms
 2  fe11-1.border1.phx1.genuity.net (207.240.103.189)  1.894 ms  13.040 ms  
1.377 ms
 3  fe-6-0.core1.phx1.genuity.net (207.240.1.1)  1.500 ms  69.045 ms  3.208 ms
 4  core1.sjc1.genuity.net (207.240.0.9)  20.429 ms  18.507 ms  18.123 ms
 5  207.240.24.178 (207.240.24.178)  20.624 ms  19.139 ms  17.908 ms
 6  sanjose1-nbr1.bbnplanet.net (4.0.3.189)  19.179 ms  20.695 ms  20.093 ms
 7  su-bfr.bbnplanet.net (4.0.1.1)  20.322 ms  23.264 ms  26.579 ms
 8  paloalto-cr8.bbnplanet.net (4.0.2.210)  26.441 ms  41.758 ms  50.069 ms
 9  digitisland.bbnplanet.net (131.119.35.82)  84.241 ms  77.681 ms  84.923 ms
10  digitisland.bbnplanet.net (131.119.35.82)  129.785 ms !X *  152.450 ms !X

-danny

> i.e.
> ping -s auth3.ipass.com.
> 64 bytes from holmes.ipass.com (204.198.128.102): icmp_seq=0. time=352. ms
> 
> yet traceroute 
> 
> ...
>  6  s2/2-decker-hi.digisle.net (167.216.156.57)  147 ms  149 ms  148 ms
>  7  s2/2-decker-hi.digisle.net (167.216.156.57)  205 ms *  147 ms
>  8  * s2/2-decker-hi.digisle.net (167.216.156.57)  152 ms *
>  9  s2/2-decker-hi.digisle.net (167.216.156.57)  148 ms *  159 ms
> 10  * s2/2-decker-hi.digisle.net (167.216.156.57)  148 ms *
> 11  s2/2-decker-hi.digisle.net (167.216.156.57)  177 ms *  161 ms
> ...
> 
> thnx in adv.