GRE tunnels between Cisco and Linux routers using iproute

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/167).
GRE tunnels between Cisco and Linux (2.4 and up) routers are possible. Given the following two routers, each one gateway for its network:

linux

Public IP: 82.72.101.226 Private network: 192.168.4.0/24 IP on that private network: 192.168.4.4

cisco

Public IP: 123.45.67.8 Private network: 192.168.10.0/24 IP on that private network: 192.168.10.4 See IP

IP in IP or GRE tunnel using iproute

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/166).
Setting an IP in IP or GRE tunnel using iproute between two Linux routers is relatively easy. Given the following two routers, each one gateway for its network:

routerA

Public IP: 87.65.43.21 Private network: 192.168.4.0/24 IP on that private network: 192.168.4.4

routerB

Public IP: 123.45.67.8 Private network: 192.168.10.0/24 IP on that private network: 192.168.10.4 To setup routerA, will issue the following commands o

Interoperating Quagga or Zebra with NET-SNMP

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/163).
Quagga is able to publish routing information to SNMP. When setting up Quagga [1] with NET-SNMP (previously know as UCD-SNMP), you may fall into the problem of Quagga logging a lot of error messages to syslog or to its own logfile. Let us analyse and fix this kind of error messages in your syslog files:
Aug 30 07:41:40 myhost snmpd[969]: refused smux peer: oid SNMPv2-SMI::enterprises.3317.1.2.1, descr quagga-0.96.5
Aug 30 07:41:46 myhost snmpd[969]: 

Quagga / Zebra

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/162).
Quagga and Zebra are Free routing softwares. Quagga is a fork of Zebra. They both still work similarly, and share of course the same configuration file format. It may probably allow you to replace Cisco routers or interoperate with them as the configuration is very similar to Cisco's CLI.

HOWTO Install and maintain free software easily under Solaris: pkg-get

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/161).
pkg-get is somewhat a rewrite of the apt-get of to Sun's Solaris. It is a script that uses wget and the pkg suite [1] of tools from Solaris to install, upgrade, and uninstall free software easily on Solaris. The list of packages available is already impressive: http://www.blastwave.org/packages.php. To

HOWTO Setup NUT (Network UPS Tools) on Debian

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/158).
NUT is the Network UPS Tools. To setup NUT on Debian, you first need to know what kind of UPS you have, and how it is/will be connected to your Debian machine. We will not yet analyse how to do monitoring over the network, but only on the machine physically connected to the UPS, which we suppose has been installed under Debian GNU/Linux (tested on Sarge). First, install the package nut (the

Advanced Web Statistics (AWStats)

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/157).
AWStats is a free powerful and featureful tool that generates advanced web, ftp or mail server statistics, graphically. This log analyzer works as a CGI or from command line and displays all possible information your log contains, in few graphical web pages.

OpenLDAP

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/153).
OpenLDAP is an open source implementation of the Lightweight Directory Access Protocol.

Name Service Switch under UNIX/Linux

This article was first written in August 2004 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/151).
Every UNIX/Linux operating system uses a set of libraries called the Name Service Switch (which is part of the LibC of the system) to resolve its names, be it for userids to login names or IP addresses to hostnames resolution, or whatever and the opposite. This library is meant to make the use of NIS, LDAP, etc… transparent to the program that will use it in the end.