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On my Linux box,
traceroute does not work. The output is like this:
$ traceroute google.com
traceroute to google.com (22.214.171.124), 30 hops max, 52 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
Can anyone tell me why it's not working? Any possible reasons behind it?
Jun 20, 2010 at 20:33
uses high UDP ports for tracing hosts. However, sometimes firewalls block these UDP ports.
Try to add the
-I (uppercase i) parameter to the command line, eg:
traceroute -I www.google.it
This will use ICMP instead of UDP for tracing hosts.
Feb 7, 2015 at 7:20
46.3k 7 7 gold badges 104 104 silver badges 171 171 bronze badges
Try to use -T (tcp) or -U (udp) to bypass firewall.
Some routers/firewall don't let icmp echo pass trough, that's why you'd use those 2 to by pass them.
Anyway, contrary as stated in wikipedia, on my debian boxes traceroute still uses icmp packets and not udp.
I was wrong...it uses udp...the icmp coming back are for an unreachable port...sorry
Jun 20, 2010 at 20:52
1,589 8 8 silver badges 6 6 bronze badges
it could be that a firewall upstream from you is blocking the UDP packets
On modern Unix-like operating systems, the traceroute utility by default uses UDP datagrams with destination ports numbering from 33434 to 33534.
Jun 20, 2010 at 20:37
This is probably because icmp TIME_EXCEEDED answer is filtered by the router/firewall that you use as default gateway or by your Linux system itself
Jun 20, 2010 at 20:45
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