Is it required, no. Does it help, yes.
The problem is getting your foot in the door and getting experience. Once you have experience at a high level (say 3 years and some admin exp.) no one will care what school you went to or your GPA or even if you have a degree.
Unfortunately a quick glance on DIce, Monster, Careerbuilder will show you that almost EVERY job says it requires a BS or an associates. Most companies put that on there as a deterrent to weed out unqualified candidates - most of the time the job technically doesn't REQUIRE a degree, but companies put it on there to help ensure they get better qualified candidates.
If you know someone or have experience you can get your foot in the door w/o a degree. If you don't it's going to be a tough track.
Sometimes degrees aren't in the cards - honestly i think unless there is major reform you will see fewer and fewer degrees in the market place because the costs are just unreasonably high for the quality of training / schooling you get. If a degree isn't in the cards do yourself a favor and start getting some certifications. If you get your A+, Net+ and/or MCSA/CCNA you can land a job no problem w/o a degree.