On a customer's network we noticed that the Internet facing router reboots because of a software error. We stumbled on this issue by chance, just because one of the reboots was during a videoconference. Nobody noticed the problem before and they really don't know if the problem was there since the installation of the …

Ping is one of the most useful tools to test network connectivity, sometimes it is the first step for troubleshooting and getting the "!" (if you work on Cisco devices) can be a big satisfaction. I use ping on daily basis and sometimes I need some features that the basic ping command lacks. The solution? FPING Of all …

A lot of useful tools to manage and monitor Windows: "The Sysinternals web site was created in 1996 by Mark Russinovich and Bryce Cogswell to host their advanced system utilities and technical information. Whether you’re an IT Pro or a developer, you’ll find Sysinternals utilities to help you manage, troubleshoot and …

Inspired by the Packet Pushers Podcast I setup my personal IPv6 tunnel to TunnelBroker.net. Registration is free and the configuration is straightforward. The first step is the registration and setup of a tunnel to our IPv4 address. Second step the configuration of the tunnel on our side. The webiste includes many …

Sometimes you just need some privacy when browsing the Internet: "Tor was originally designed, implemented, and deployed as a third-generation onion routing project of the U.S. Naval Research Laboratory. It was originally developed with the U.S. Navy in mind, for the primary purpose of protecting government …

I needed to change the RDP listening port on a Windows machine, just edit the registry key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp\PortNumber HTH

You can either do a planned, careful migration, or you can do it in a panic, and you should know full well that panicking is more expensive. Martin Levy, director of IPv6 strategy for Hurricane Electric

Inspired by the CodeAcademy project, I've decided to learn a programming language this year. Back in high school I've learnt [Pascal](http://en.wikipedia.org/wiki/Pascal_(programming_language), Delphi, Assembly and [C](http://en.wikipedia.org/wiki/C_(programming_language) but many years passed so I forgot all the …

Remember: voice Vlan is not automatically created when applied to a port. You must create it!

Number 8 is the one I mention when I see a network project made with PowerPoint that looks simple with all those clouds and arrows: (8) It is more complicated than you think. Link to all the 12 truths HERE

Glogg is a tool to browse and search through text files. I find it very useful to search in log files, it's light and fast. It can also follow a file, so there's no need to reopen the file or refresh if something changes. Update 01/2022 It seems glogg's website is not maintained anymore. KLOGG is a valid alternative …

A customer called today for a strange issue on their Cisco ASA. They have 60Mbit internet connection and a big event is filling the bandwidth. The session graph is what they are worried about: This is a perfect example of TCP Sync, well explained HERE. The ISP applies a basic rate-limit rule on the router that causes …

Quite often when a network configuration includes authentication or 802.1x on network devices Radius is the protocol of choice. Info NtRadPing is a free utility to test a Radius server. The usage is simple: insert the IP address of the radius server, the secret, user name and password of the user to test. Remember to …

HP allows Cisco certified people to achieve it's MASE/ASE certs using Fast Track: While HP certifications aren't as popular as Cisco's they can be a way to learn a different platform and increase career opportunities. The official cert guide is available on Amazon.

This website will be the new platform for my blog www.ifconfig.it. The migration has just begun, I'm copying the most interesting post from the old blog here, it'll take some time. I used to manage the website with RapidWeaver but in the last year I'm using a Win7 PC most of the time and I needed a more flexible …