My Port is being wierd....

Hello, I'm having a rather odd problem i cant entirely explain. Please excuse me if by chance there is already a topic on this. In short terms, sometimes the port works, however somtimes it dosent. I have 3 successfully forwarded ports for 25565, TCP, UDP, and TCP/UDP. This is not a new problem, either, the server was started in January, 2013, maybe 10 months ago and i've allways had this problem, so its not anything like the version. Not any errors either, my log is 100% error free as far as i know. The server allways shows when I use the LAN connection, and the WAN allways works from the host machine. I check the connection and port on websites all the time wich almost allways respond no connection, however my friends are playing on the server at the same time. Most players can connect most of the time but some rarely ever get connection. The way I go about fixing this is I swich Wifi networks (i have two, one directly to my router, and one directly to my modem.) If they dont get connection, I go back to the network i use default to host my server from, directly to the modem. And this will usauly fix it temporaraly, if they disconnect, they may not get connection anymore. Thats about all i can think of. If you need anymore information i will be gald to post it, I'll post the connection speed/ect. shortly. Thx