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.
Some time ago I installed a new firewall at the customer’s site. Meanwhile the customer was interested in the flows that are traversing through the firewall right now. Oh. Good question. Of course it is easy to filter through log messages of firewalls, but theses logs are only for finished sessions. Yes, there are “session browsers” or the like on all firewalls, but they are not nice and handy to analyze the sessions in real-time.
The solution was to bring a network analyzer on a mirror port near to the firewall. I decided to use ntopng running on the live Linux distribution Knoppix. Great choice! An old notebook with two network adapters fits perfectly. A handful commands and you’re done:
When explaining IPv6 I am always showing a few Wireshark screenshots to give a feeling on how IPv6 looks like. Basically, the stateless autoconfiguration feature (SLAAC), DHCPv6, Neighbor Discovery, and a simple ping should be seen/understood by any network administrator before using the new protocol.
Therefore I captured the basic IPv6 autoconfiguration with a Knoppix Linux behind a Telekom Speedport router (German ISP, dual-stack) and publish this capture file here. I am using this capture to explain the basic IPv6 features.
While parsing logfiles on a Linux machine, several commands are useful in order to get the appropriate results, e.g., searching for concrete events in firewall logs.
In this post, I list a few standard parsing commands such as grep, sort, uniq, or wc. Furthermore, I present a few examples of these small tools. However, it’s all about try and error when building large command pipes. ;)
I am using such an installation for my firewalls, routers, etc., to have an archive with all of its messages. Later on, I can grep through these logfiles and search for specific events. Of course it does not provide any built-in filter or correlation features – it is obviously not a SIEM. However, as a first step it’s better than nothing. ;)
This is a tutorial on how to configure the GlobalProtect Gateway on a Palo Alto firewall in order to connect to it from a Linux computer with vpnc.
Short version: Enable IPsec and X-Auth on the Gateway and define a Group Name and Group Password. With this two values (and the gateway address), add a new VPN profile within vpnc on the Linux machine. Login with the already existing credentials.
Long version with screenshots comes here:
This post describes how to add a Linux machine to the MRTG/Routers2 monitoring server. First, the host must be able to process SNMP requests. Then, a *.cfg file for MRTG/Routers2 is created by running the “cfgmaker” tool with a host-template. Since a few values are wrong in the cfgmaker file, I also explain how to correct them. Finally, I am adding the mrtg-ping-probe lines to the configuration.
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
A few days ago I needed to use vi for a simple change in a single file. However, I am not using vi in normal situations since I prefer the usage of “nano“. Since I only needed to edit a few lines, all the command references I found on the Internet were much to overwhelmed, so I decided to write a really tiny vi tutorial which only shows the commands in order to edit a file and to close it afterwards. Here we go:
Open the file with vi textfile.
Go into the edit mode with “i” and edit the text. When you are finished, hit the Esc key to leave the edit mode. Type a colon followed by an “x” (appears at the bottom line) to quit vi with saving the changes. Thats it. Here is the sequence at a glance:
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: