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Linux and Unix traceroute command tutorial with examples

Tutorial on using traceroute, a UNIX and Linux command for showing the route packets take to a network. Examples of tracing a route, using IPv6, disabling hostname mapping and setting the number of queries per hop.

Estimated reading time: 5 minutes

Table of contents

Terminal showing traceroute man page

What is the traceroute command in UNIX?

The traceroute command shows how a data transmission travelled from a local machine to a remote one. A typical example would be loading a web page. Loading a web page over the internet involves data flowing through a network and a number of routers. The traceroute command can show the route taken and the IP and hostnames of routers on the network. It can be useful for understanding latency or diagnosing network issues.

How to trace the route to a network host

To trace the route to a network host pass the ip address or name of the server you want to connect to.

traceroute google.com
traceroute to google.com (172.217.23.14), 30 hops max, 60 byte packets
 1  10.8.8.1 (10.8.8.1)  14.499 ms  15.335 ms  15.956 ms
 2  h37-220-13-49.host.redstation.co.uk (37.220.13.49)  17.811 ms  18.669 ms  19.346 ms
 3  92.zone.2.c.dc9.redstation.co.uk (185.20.96.137)  19.096 ms  19.757 ms  20.892 ms
 4  203.lc3.redstation.co.uk (185.5.3.221)  28.160 ms  28.415 ms  28.665 ms
 5  100.core1.the.as20860.net (62.128.218.33)  26.739 ms  27.840 ms  28.847 ms
 6  110.core2.thn.as20860.net (62.128.218.26)  29.112 ms  18.466 ms  19.835 ms
 7  be97.asr01.thn.as20860.net (62.128.222.205)  19.986 ms  20.488 ms  21.354 ms
 8  * * *
 9  216.239.48.143 (216.239.48.143)  24.364 ms 216.239.48.113 (216.239.48.113)  25.069 ms  25.592 ms
10  108.170.233.199 (108.170.233.199)  26.239 ms  27.369 ms  28.031 ms
11  lhr35s01-in-f14.1e100.net (172.217.23.14)  28.642 ms  29.311 ms  29.815 ms

The output shows a number of things:

By default traceroute sends three packets for each host so three response times are listed.

To demonstrate seeing increased latency the following example runs the same command whilst connected to a VPN in Australia. The route is different and takes much longer.

traceroute google.com
traceroute to google.com (172.217.25.46), 30 hops max, 60 byte packets
 1  10.8.8.1 (10.8.8.1)  316.212 ms  316.393 ms  317.031 ms
 2  107.181.128.1 (107.181.128.1)  322.328 ms  326.666 ms  326.872 ms
 3  au-sy3-bdr-0-0.as58940.net.au (43.245.167.1)  321.205 ms  326.474 ms  327.065 ms
 4  as15169.nsw.ix.asn.au (218.100.52.3)  327.626 ms  327.762 ms  328.033 ms
 5  216.239.43.157 (216.239.43.157)  328.232 ms 216.239.47.81 (216.239.47.81)  328.427 ms 216.239.43.157 (216.239.43.157)  328.631 ms
 6  108.170.233.193 (108.170.233.193)  328.817 ms 108.170.233.195 (108.170.233.195)  316.259 ms  317.409 ms
 7  syd15s02-in-f14.1e100.net (172.217.25.46)  317.079 ms  321.961 ms  322.113 ms

The following example shows a traceroute that fails to reach the destination.

traceroute google.com
traceroute to google.com (172.217.25.46), 30 hops max, 60 byte packets
 1  10.8.8.1 (10.8.8.1)  316.212 ms  316.393 ms  317.031 ms
 2  107.181.128.1 (107.181.128.1)  322.328 ms  326.666 ms  326.872 ms
 3  au-sy3-bdr-0-0.as58940.net.au (43.245.167.1)  321.205 ms  326.474 ms  327.065 ms
 4 * * *
 5 * * *
 6 * * *
 7 * * *
...

In this example the asterisks show packet loss. This could mean a network outage, high amounts of traffic leading to network congestion or a firewall dropping traffic. Whatever the reason the traceroute command shows the destination is not reached.

How to trace the route using IPv6

To trace the route to a network host using the IPv6 protocol pass the -6 option.

traceroute -6 ipv6.google.com

How to disable IP address and hostname mapping.

To disable IP address mapping in traceroute use the -n option.

traceroute -n google.com
traceroute to google.com (172.217.23.14), 30 hops max, 60 byte packets
 1  10.8.8.1  14.692 ms  15.529 ms  15.976 ms
 2  37.220.13.49  18.429 ms  19.559 ms  20.153 ms
 3  185.20.96.137  19.123 ms  19.897 ms  20.721 ms
 4  185.5.3.221  24.759 ms  25.124 ms  25.868 ms
 5  62.128.218.33  26.558 ms  27.244 ms  28.342 ms
 6  62.128.218.26  28.929 ms  18.275 ms  18.448 ms
 7  62.128.222.205  19.139 ms  22.730 ms  22.148 ms
 8  * * *
 9  216.239.48.113  20.806 ms 216.239.48.143  18.909 ms 216.239.48.113  19.382 ms
10  108.170.233.199  19.516 ms 108.170.233.197  19.853 ms  19.884 ms
11  172.217.23.14  19.893 ms  19.449 ms  19.496 ms

How to set the number of queries per hop

To set the number of queries per hop in traceroute use the -q option.

traceroute -q 1 google.com
traceroute to google.com (172.217.23.14), 30 hops max, 60 byte packets
 1  10.8.8.1 (10.8.8.1)  14.845 ms
 2  h37-220-13-49.host.redstation.co.uk (37.220.13.49)  16.874 ms
 3  92.zone.2.c.dc9.redstation.co.uk (185.20.96.137)  16.683 ms
 4  203.lc3.redstation.co.uk (185.5.3.221)  20.784 ms
 5  100.core1.the.as20860.net (62.128.218.33)  21.280 ms
 6  110.core2.thn.as20860.net (62.128.218.26)  22.071 ms
 7  be97.asr01.thn.as20860.net (62.128.222.205)  22.890 ms
 8  *
 9  216.239.48.143 (216.239.48.143)  24.815 ms
10  108.170.233.199 (108.170.233.199)  25.175 ms
11  lhr35s01-in-f14.1e100.net (172.217.23.14)  25.812 ms

How to set response wait time

To configure the response wait time in traceroute use the -w option. The supports specifying how long to wait in seconds for a response to a probe. In the following example this is set to one second.

traceroute -w 1 google.com

How to specify the interface to use

To set the network interface that traceroute should use use the -i option. If this is not set the interface is selected according to the routing table.

traceroute -i wlp3s0b1 google.com

Further reading

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