Introduction
When managing a Linux server or troubleshooting network issues, it’s crucial to have the right tools to check open ports and active connections. One of the most common tools for this is netstat
. However, netstat
is not always installed by default on modern Linux distributions. In this blog post, we’ll guide you on how to install netstat
and discuss an alternative tool called ss
.
Installing netstat
on Linux
netstat
is part of the net-tools
package, which contains a set of networking tools for Linux. This package is often not installed by default on newer Linux distributions, but you can install it easily.
Step 1: Install net-tools
To install netstat
, you’ll need to install the net-tools
package. The installation command differs depending on your distribution.
For Debian/Ubuntu-based systems, use the following commands:
sudo apt-get update
sudo apt-get install net-tools
For Red Hat/CentOS-based systems, use the following commands:
sudo yum install net-tools # For older systems
sudo dnf install net-tools # For newer systems
Step 2: Use netstat
Once net-tools
is installed, you can use netstat
to check open ports and active connections:
netstat -tuln
Here’s a quick explanation of the options:
-t
: Show TCP connections.-u
: Show UDP connections.-l
: Show only listening ports.-n
: Show numerical addresses instead of resolving hostnames.
This will show you all the listening ports on your system, along with the protocol and IP addresses.
The ss
Command: A Modern Alternative
While netstat
has been around for a long time, it’s considered somewhat outdated. Modern Linux systems often prefer the ss
(Socket Statictics) command, which is faster and more efficient than netstat
.
Using ss
If netstat
isn’t available or you prefer using the more modern alternative, you can use ss
. It provides similar functionality with improved performance.
Here’s the equivalent command using ss
:
ss -tuln
Just like netstat
, it shows active connections and open ports. The options work the same way:
-t
: Show TCP connections.-u
: Show UDP connections.-l
: Show only listening ports.-n
: Show numerical addresses.
Why Use ss
Over netstat
?
- Faster Performance:
ss
can display information much faster thannetstat
, especially on systems with many open connections. - More Features:
ss
provides more detailed statistics and is better optimized for modern Linux systems.
Conclusion
Both netstat
and ss
are invaluable tools for system administrators to monitor network activity on Linux systems. While netstat
is still widely used, we recommend using ss
for faster and more efficient performance.
If you need to install netstat
, it’s as simple as installing the net-tools
package. However, consider adopting ss
as your go-to networking tool for more modern and performance-oriented solutions.