Some months ago, my co-worker and I ran into an interesting issue: a notebook with a newly installed Ubuntu 20.04 does only work with IPv4, but this office network is dual-stacked (IPv4 and IPv6). Other Linux clients as well as Windows and Mac systems still work fine. They all get an IPv4 configuration by DHCPv4 and an IPv6 configuration by stateful DHCPv6 from the same DHCP server, relayed by a Cisco ASA 5500-X. What’s wrong with Ubuntu 20.04?
Haha, do you like acronyms as much as I do? This article is about the feature from Palo Alto Networks’ Next-Generation Firewall for Internet Protocol version 6 Neighbor Discovery Protocol Router Advertisements with Recursive Domain Name System Server and Domain Name System Search List options. ;) I am showing how to use it and how Windows and Linux react on it.
This is a basic tutorial on how to install BIND, the Berkeley Internet Name Domain server, on a Ubuntu server in order to run it as an authoritative DNS server. It differs from other tutorials because I am using three servers (one as a hidden primary and two secondaries as the public accessible ones), as well as some security such as denying recursive lookups and public zone transfers, as well as using TSIG for authenticating internal zone transfers. That is, this post is not an absolute beginner’s guide.
Some time ago I published a post introducing ntopng as an out-of-the-box network monitoring tool. I am running it on a Knoppix live Linux notebook with two network cards. However, I have a few customers that wanted a persistent installation of ntopng in their environment. So this is a step-by-step tutorial on how to install ntopng on a Ubuntu server with at least two NICs.
Roundcube is an email webclient which is easy and intuitive to use. I am using it for my private mails, connecting via IMAP and SMTP to my hoster. One of the great advantages is the “flag” option which is synchronized via IMAP to my Apple devices.
Following is a step-by-step installation guide for Roundcube plus an update scenario. It is a kind of “memo for myself”, but hopefully, others can use it as well.
If you want to use you own ownCloud installation, you can find several documentation on the Internet on how to set up this server, e.g. the official ownCloud documentation, or installation guides such as this or that or here. But none of these page alone provided enough information for installing a secure server completely from the beginning.
So here comes my step-by-step guide which surely won’t be complete, too. ;) However, hopefully it will help other people while searching for their way to install ownCloud. Additionally I am showing how to upgrade an ownCloud server.
I always wanted to monitor my private network with an open source tool. Since I knew some nice statistics, e.g. from the DE-CIX (printed with RRDtool) or from the Uni-Gießen (generated with MRTG), I had the idea of installing such a system by myself. Luckily I found a book from Steve Shipway, called “Using MRTG with RRDtool and Routers2“, which actually disappointed me because it did not offer a complete installation guide but mainly further information about fine-tuning the appropriate tools.
Therefore, I want to show a complete step-by-step installation of all the needed tools in order to monitor a network with MRTG, RRDtool and Routers2. “From scratch” means that there are no prerequisite to this installation guide except a plain Linux server (in my case a Ubuntu Linux) such as presented here. Okay, let’s go: Continue reading MRTG with RRDtool and Routers2 – Installation from Scratch
Okay, I know this contains nothing new for many of you but I need it from time to time: It is simply a list of tools I need after a new Linux server installation (used with Ubuntu server) as well as some further hints for the installation process such as static IP addresses, NTP or Syslog forwarding. So, after the initial installation of a server I am doing the following steps: