Friends cannot connect but bro can...

So I started a Bukkit server for my friends in school to have a once-a-fortnight zombie-survival.

The problem is that my friends keep on Getting the 'Connection failed: timeout' error. I have placed my Default Gateway IP into Config and forwarded 25565 with the last number of my 192.168.1.6 IP. This is what the tutorial said to do.

I then proceeded to give my brother the Default Gateway IP and he connected. My friends tried this too and it didn't work. So i gave them my global IP and that STILL didn't work.

Any help for a newbie?

EDIT:
@ECHO OFF
SET BINDIR=%~dp0
CD /D "%BINDIR%"
"%ProgramFiles(x86)%\Java\jre6\bin\java.exe" -Xincgc -Xmx1G -jar craftbukkit-0.0.1-SNAPSHOT.jar
PAUSE

Is my Start.bat

#Minecraft server properties
#Fri Sep 09 20:23:36 CDT 2011
level-name=world
allow-nether=true
view-distance=10
spawn-monsters=true
online-mode=true
spawn-animals=true
max-players=20
server-ip=192.168.1.6
pvp=true
level-seed=
server-port=25565
allow-flight=false
white-list=false

Is my Server props

It may be worthwhile noting that me and my bro are on the Same network.

 

Get the 192.168.1.6 away and leave it blank

 

Did you give your friends the 192.168.1.6 ip? because that wont work for them. They need the one you would get from www.ipchicken.com