Fatigue.
Anguish.
Four days of near-sleepless nights.
Clueless, mindless telco droids carrying out orders that don't consider the customer.
Disgruntled, interrupted users.
Cables - lots of cables.
Dialog boxes with IP addresses.
Reformatted hard drives.
Grumpy DNS servers.
Telephony interfaces.

The network changes are done and things are finally the way I want 'em. Time to get some sleep.