I have 9 years of experience with Linux and Windows servers and networking.
I was and currently still am managing around 50 of them in various roles.
The fields that I specialise in are:
- Webservers (Apache, Nginx, Lighttpd, Varnish)
- App servers (Mainly Java based (JBoss, Tomcat) but also solutions for hosting PHP, Python and RoR)
- DB Servers (PostgreSQL and MySQL)
- Network services (OpenVPN, DNS, DHCP, iptables firewalls, etc.)
- Email services (Postfix, dovecot and all the protections for the email (antivirus, antispam, dkim, rbl, etc.)
- Active Directory
- Exchange (2003, 2007, 2010)
- Network services (DNS, RRAS, etc.)
- Web/app servers (IIS + all java based)
- MS SQL Server
- ACLs, services
- routing (BGP, OSPF) and switching (VLANs, VTP, ...)
- VPN, IPSec tunnels