I know for a fact that it sometimes filters my IP and sometimes doesn't, even though I have stayed in the same place while checking (really don't know if that matters).
When I first added the filter I noticed right away I was being filtered since I disappeared from the counter. But now, a few hours later, when I started modifying my webpage (a tumblr if it's of any relevance), I see my session being counted, switched to another post to make sure it was mine, and it was, since google analytics changed the name of the webpage that was active, and there was only one active user. So I added another filter thinking the old one was wrong, didn't delete the first one so there are two separate filters working now, but that didn't seem to work right away. Probably 10 minutes passed and my session was being filtered without changing any of the two filters.
I now checked the filters and both have different ip addresses, what I did to obtain my IP address was just google "what is my ip address?" and click any link.
The first IP is: 188.8.131.52
The second IP is: 184.108.40.206
Both filters are in the format: "Filter" --> "Predefined" --> "Exclude" --> "IP traffic" --> "Equals to " --> IP number --> "Apply to " --> "Every data from the webpage"