Exploring Network Paths: Linux Equivalent of Tracert

When it comes to troubleshooting network connectivity issues, understanding the route that data takes from the source to the destination is crucial. While Windows users are familiar with the ‘tracert’ (Trace Route) command, Linux users have an equivalent tool known as ‘traceroute.’ In this article, we will delve into the Linux equivalent of tracert, exploring its features, usage, and how it helps in diagnosing network problems.

Introduction to Traceroute in Linux

Traceroute is a network diagnostic tool used to track the pathway that packets take from one host to another on an Internet Protocol (IP) network. In Linux, the ‘traceroute’ command provides similar functionality to the ‘tracert’ command in Windows. Traceroute sends a series of packets to the destination with incrementally increasing Time-To-Live (TTL) values, allowing it to discover the routers and nodes along the route.

Basic Syntax of Traceroute

The basic syntax of the ‘traceroute’ command in Linux is as follows:

traceroute [options] [hostname or IP address]

• Options: Traceroute has several options that allow users to customize its behavior. Common options include ‘-I’ for using ICMP Echo Request, ‘-U’ for using UDP instead of ICMP, and ‘-n’ to display numeric IP addresses.
• Hostname or IP address: This is the destination for which you want to trace the route.

Using Traceroute

Let’s explore the usage of ‘traceroute’ with a practical example. Suppose we want to trace the route to the Google DNS server (8.8.8.8). The command would be:

traceroute 8.8.8.8

This command will display a list of hops along with their IP addresses and response times, helping us identify potential network issues.

Understanding the Output

The output of the ‘traceroute’ command provides valuable information. Each line represents a hop, showcasing the IP address of the router or node and the time it took for the packet to travel to that point.

 1  _gateway (192.168.1.1)  0.418 ms  0.383 ms  0.359 ms
 2  10.0.0.1 (10.0.0.1)  1.041 ms  1.018 ms  1.002 ms
 3  example-isp-router (203.0.113.1)  3.259 ms  3.242 ms  3.225 ms
 4  some-external-router (198.51.100.1)  10.551 ms  10.533 ms  10.514 ms
 ...

Here, ‘ms’ stands for milliseconds, and the times represent the round-trip time for packets.

Advanced Usage and Troubleshooting

Specifying Protocol

By default, ‘traceroute’ uses UDP for probing. To use ICMP, you can use the ‘-I’ option:

traceroute -I 8.8.8.8

Displaying Numeric IP Addresses

To display numeric IP addresses instead of resolving hostnames, use the ‘-n’ option:

traceroute -n 8.8.8.8

Visualizing the Route with MTR

While ‘traceroute’ provides a snapshot of the route, sometimes a more dynamic and continuous view is needed. Enter MTR (My Traceroute), a powerful tool that combines the features of ‘traceroute’ and ‘ping’ into one. It continuously traces the route to the destination, providing real-time statistics.

Installation of MTR

MTR might not be pre-installed on all Linux distributions. You can install it using your package manager. For example, on Ubuntu/Debian-based systems:

sudo apt-get install mtr

Basic Usage of MTR

To use MTR, simply provide the destination IP address or hostname:

mtr 8.8.8.8

MTR displays a continuous updating screen, showcasing the packet loss, average response times, and the route.

Digging Deeper with Traceroute Options

Setting Maximum Hops

You can limit the number of hops with the ‘-m’ option. For instance, to limit to 15 hops:

traceroute -m 15 8.8.8.8

Specifying Port for UDP Probing

If you are using UDP and want to specify the port, you can use the ‘-p’ option:

traceroute -U -p 33434 8.8.8.8

Resolving Hostnames

If you want to resolve hostnames, use the ‘-a’ option:

traceroute -a 8.8.8.8

By mastering these tools, network administrators can efficiently troubleshoot and optimize network paths, ensuring smooth and reliable connectivity. The ability to visualize the journey of data packets is paramount in maintaining a healthy network environment, and Linux provides the necessary utilities to achieve this.