This is the best description I have read regarding the Network Admin position.
When I started as an admin 5 years ago, the company didn't know to care about redundancy, or security. When I started, neither did I. I could build PCs, do some light programming, and had a knack for finding solutions with Google. In that time, I've replaced all network hardware and fixed the topology, expanded from 6 to 20 servers, added virtualization wherever possible, added battery backup to everything (many servers didn't have any UPS), replaced 100 windows 2000 desktops, added 100 more desktops, upgraded the domain from 2000 to 2008, Exchange upgrades twice, migrated all storage to redundant RAID on server or via NAS, maintained DAILY tape backups of all servers, network monitoring via free Linux tools, expanded the network via T1 to include 7 satellite facilities and WAPs with VPN/firewall, and locked down every damned machine so that nobody can install anything. All while providing these people and locations with 24/7 tech support and software instruction. Monitoring scripts are all Perl and PowerShell, depending on OS. All of our network hardware is either Adtran or 3Com (now HP) and I've only had one switch failure in 5 years. No training seminars or certification taken, just lots of reading.
It pays shit, but its steady.