The sys admin's daily grind: ASN
Charly's Column – ASN
When digging into BGP routing information, Charly avoids the highway through parameter hell thanks to the ASN tool. In addition to a system's AS number, ASN delivers other information, such as its peering partners upstream and downstream.
Every admin knows how to deal with IP addresses. Unfortunately, IPs never turn up alone. They belong to a network, and the network is almost always assigned to an autonomous system (AS), which uses the Border Gateway Protocol (BGP) to exchange routing information.
There is a simple way to find out which AS a particular individual IP belongs to. By way of an example, the following is the IP address of Computec Media's web server, www.computec.de. The associated IP address 62.146.104.133 can be discovered using dig
or by simply pinging.
I then feed this IP address to a tool named ASN [1]. The shell script aggregates the output of several other tools and presents the results in a clear-cut way. It has a number of dependencies that vary depending on the distribution you are using. What exactly needs to be installed for ASN to work is explained in a separate section on the tool's GitHub page.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
USB4 Maintainer Leaves Intel
Michael Jamet, one of the primary maintainers of USB4 and Thunderbolt drivers, has left Intel, leaving a gaping hole for the Linux community to deal with.
-
Budgie 10.9.3 Now Available
The latest version of this elegant and configurable Linux desktop aligns with changes in Gnome 49.
-
KDE Linux Alpha Available for Daring Users
It's official, KDE Linux has arrived, but it's not quite ready for prime time.
-
AMD Initiates Graphics Driver Updates for Linux Kernel 6.18
This new AMD update focuses on power management, display handling, and hardware support for Radeon GPUs.
-
AerynOS Alpha Release Available
With a choice of several desktop environments, AerynOS 2025.08 is almost ready to be your next operating system.
-
AUR Repository Still Under DDoS Attack
Arch User Repository continues to be under a DDoS attack that has been going on for more than two weeks.
-
RingReaper Malware Poses Danger to Linux Systems
A new kind of malware exploits modern Linux kernels for I/O operations.
-
Happy Birthday, Linux
On August 25, Linux officially turns 34.
-
VirtualBox 7.2 Has Arrived
With early support for Linux kernel 6.17 and other new additions, VirtualBox 7.2 is a must-update for users.
-
Linux Mint 22.2 Beta Available for Testing
Some interesting new additions and improvements are coming to Linux Mint. Check out the Linux Mint 22.2 Beta to give it a test run.