I am diagnosing some mysterious network latency that comes and goes with my wife's MacBook Pro.
As part of this diagnostic work, I fired up Network Utility and used its interface to traceroute
to trace the route to www.google.com
. Somewhat oddly, all of the results were of the * * *
variety.
Suspicious, I opened up traceroute
directly from Terminal and issued traceroute www.google.com
. There was a * * *
from the second hop (right after my 10.0.0.1
entry) but then everything flowed normally.
I then eliminated DNS issues by using traceroute against the IP address directly.
This behavior happens on all Macs in our house, so it's not computer-specific.
Here is the output from the command line (which worked):
traceroute to 173.194.33.116 (173.194.33.116), 64 hops max, 52 byte packets
1 10.0.0.1 (10.0.0.1) 115.994 ms 1.265 ms 1.816 ms
2 * * *
3 te-5-2-ur02.bremerton.wa.seattle.comcast.net (68.87.205.57) 14.209 ms 12.736 ms 11.514 ms
4 ae-22-0-ar03.seattle.wa.seattle.comcast.net (69.139.164.153) 18.753 ms 14.804 ms 15.076 ms
5 he-1-4-0-0-10-cr01.seattle.wa.ibone.comcast.net (68.86.94.237) 19.233 ms
he-1-7-0-0-10-cr01.seattle.wa.ibone.comcast.net (68.86.91.165) 18.523 ms
he-1-12-0-0-10-cr01.seattle.wa.ibone.comcast.net (68.86.93.173) 16.625 ms
6 he-0-11-0-1-pe04.seattle.wa.ibone.comcast.net (68.86.85.38) 15.435 ms 21.009 ms 14.535 ms
7 23.30.207.2 (23.30.207.2) 16.739 ms 14.500 ms 15.909 ms
8 209.85.249.34 (209.85.249.34) 16.002 ms 17.200 ms 16.781 ms
9 209.85.244.63 (209.85.244.63) 15.472 ms 17.927 ms 15.836 ms
10 sea09s16-in-f20.1e100.net (173.194.33.116) 15.860 ms 27.057 ms 16.399 ms
And here is the output from Network Utility:
Leaving aside the &)$(*^#& problem that I'm actually trying to solve, what would account for why the two traceroute
invocations would produce different output? If it matters, traceroute
-via-Network-Utility never works; the command line always does.
Best Answer
Network Utility is using ICMP rather than the default UDP protocol used by
traceroute
. You can use the-I
flag to get the same behaviour on the command line:I don't know of any way to force Network Utility to use UDP.
One explanation for this could be that your firewall/router is configured to block ICMP packets.