Advanced Tracing
Charly's Column – traceroute
Like every admin, Charly regularly uses the classic traceroute tool. If unfriendly digital natives interfere with an ICMP filter, he simply switches to a clever alternative like LFT.
Practically every admin uses the classic traceroute tool at more or less regular intervals. This gets me all the more irritated when I find myself in a hotel with a WiFi network where the admin has completely disabled ICMP. Apart from the fact that this causes more trouble than benefits in what is by definition a public network, it can be easily circumvented.
The first version of traceroute was written in 1988 by a certain Van Jacobsen – Van is his first name, not an honorific. To be able to trace the path of packets through the web, Jacobsen came up with a clever method. He sent test packets through the Internet to a defined destination and increased the time to live (TTL) value for each packet.
The first packet is assigned a TTL of one. Each router that transports the packet further reduces the TTL by one. Once the TTL reaches a value of zero, the router sends it back with an ICMP TTL exceeded message. By successively increasing the TTL, Jacobsen got the packets back from routers that were further and further away and was able to follow the path of the packet until it finally reached its destination.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
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
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.
-
EndeavorOS Mercury Neo Available
A new release from the EndeavorOS team ships with Plasma 6.3 and other goodies.
-
Fedora 42 Beta Has Arrived
The Fedora Project has announced the availability of the first beta release for version 42 of the open-source distribution.
-
Dash to Panel Maintainer Quits
Charles Gagnon has stepped away as maintainer of the popular Dash to Panel Gnome extension.
-
CIQ Releases Security-Hardened Version of Rocky Linux
If you're looking for an enterprise-grade Linux distribution that is hardened for business use, there's a new version of Rocky Linux that's sure to make you and your company happy.
-
Gnome’s Dash to Panel Extension Gets a Massive Update
If you're a fan of the Gnome Dash to Panel extension, you'll be thrilled to hear that a new version has been released with a dock mode.
-
Blender App Makes it to the Big Screen
The animated film "Flow" won the Oscar for Best Animated Feature at the 97th Academy Awards held on March 2, 2025 and Blender was a part of it.
-
Linux Mint Retools the Cinnamon App Launcher
The developers of Linux Mint are working on an improved Cinnamon App Launcher with a better, more accessible UI.
-
New Linux Tool for Security Issues
Seal Security is launching a new solution to automate fixing Linux vulnerabilities.