IT jobs are anything but permanent. The average duration of an IT job is less than three years--and those are the ones that are considered "permanent!"
The way you leave a job can have a huge impact on your overall career. Our community is really not that big. Forget six degrees of separation. After you've been in IT for a few years in a few different companies, it is surprising to find people who are more than 2 connections away from you on LinkedIn.
It can be tempting to leave a job in a dramatic way. Who among us hasn't had the urge to tell people exactly what we think and storm out? Don't do it. That would be a really bad idea.
In the first place, it is far easier to find a job when you have a job. Grit your teeth. Be professional. Continue to do an exemplary job. And start looking for your next employer.
You'll be in a much stronger position when you are negotiating salary or other requirements if your new employer thinks you are perfectly happy to stay where you are. Use that to your advantage. You'll have to live with whatever deal you cut for a while; you may as well make it as sweet as you can.
Then, when you leave, make sure that your transition is purely textbook. Leave behind documentation on what you do for a living and how you do it. Try to leave as few loose ends as possible. Leave a clean desk. The people you leave behind may be the ones you need to provide you a reference when you are ready for your next job search in a few years.
PS:
Here's a nice article from Ladders about how to resign gracefully.