* MS-DOS, MS Windows (3.x, 9x, NT, 2000, XP, Vista)
* UNIX (Sun Solaris, HP-UX, NetBSD, OpenBSD, FreeBSD)

* GNU/Linux: (Debian, RedHat, Fedora Core, SuSE, OpenWRT, Knoppix)
* ISC BIND, ISC DHCP
* OpenLDAP

* VMware
* FreeRADIUS, GNU/Radius
* LVM (Storage)
* RAID

 

* Ethernet, IPv4, IPv6, IPSec, SSL
* Firewall Konzept und Architektur (PF, SunScreen, iptables)
* IRP (RIPv1, RIPv2, RIPng); ERP (BGP-4)
* Naming and Directory Services
* NFS, SMB/CIFS (Samba)
* SSO/Kerberos V
* Internetworking (Routing, NAT/PAT/NAPT, ...)