Master Linux Traceroute: 12 Powerful Commands to Diagnose Network Paths

Introduction

Network engineers and operations staff frequently use the traceroute command to diagnose connectivity, as it reveals the path packets take from a source to a destination. While many only know the basic usage, this guide provides twelve practical examples to fully master traceroute.

Prerequisite Knowledge

Before diving into commands, review the network topology diagram below, which shows two possible routes from a computer to a server:

The paths are Computer->R1->R2->R4->Server and Computer->R1->R3->R4->Server. Traceroute can reveal which route is actually taken.

Installing traceroute on Linux

First identify the Linux distribution:

root@ecs-adf0-0003:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.4 LTS
Release:        20.04
Codename:       focal

On Ubuntu, install with: apt install traceroute If using CentOS or Fedora, use yum install traceroute instead.

Using traceroute

4.1 Basic Usage

traceroute host

The command lists each router the packets traverse. Example tracing the site www.wljslmz.cn shows 20 hops:

4.2 Change Wait Time

The default per‑hop timeout is 3 seconds. Adjust it with -w:

traceroute -w 1 www.wljslmz.cn

4.3 Change Number of Probes per Hop

Default is 3 probes. Use -q to set a different count, e.g., 5:

traceroute -q 5 www.wljslmz.cn

4.4 Change Maximum Hop Count

The default max‑hops is 30 (extendable to 255). Use -m to limit it, e.g., to 10:

traceroute -m 10 www.wljslmz.cn

4.5 Change Starting TTL

TTL (Time‑To‑Live) limits how many hops a packet can travel. Adjust the initial TTL with -f:

traceroute -f 8 www.wljslmz.cn

4.6 Disable Hostname Resolution

Suppress domain names in the output with -n:

traceroute -n www.wljslmz.cn

4.7 Trace a Different Destination Port

By default traceroute targets port 80. Change it with -p:

traceroute -p 2222 www.wljslmz.cn

4.8 Change Maximum Packet Size

The default packet size is 60 bytes. Increase it by appending a size argument:

traceroute www.wljslmz.cn 200

Setting a size smaller than the minimum (28 bytes) has no effect, as shown when using 1 as the size argument.

4.9 IPv4 Tracing

traceroute -4 www.wljslmz.cn

4.10 IPv6 Tracing

traceroute -6 www.wljslmz.cn

The target site does not support IPv6.

4.11 Use ICMP ECHO Instead of UDP

Switch to ICMP mode with -I:

traceroute -I www.wljslmz.cn

4.12 Save Traceroute Output to a File

Redirect the output for offline analysis:

traceroute www.wljslmz.cn > wljslmz.txt

View the saved file with more wljslmz.txt as shown in the screenshot.

Conclusion

The traceroute command is a simple yet powerful network diagnostic tool. This article presented twelve practical examples, enabling readers to customize timeouts, probe counts, hop limits, TTL values, hostname resolution, destination ports, packet sizes, IPv4/IPv6 modes, ICMP usage, and output persistence for effective troubleshooting.