How to close port 7547 on the O2 Wireless Box II/III

By default, the O2 Wireless Box II/III listens on port 7547 to the whole of the internet. The port is used by O2 for the CPE WAN Management Protocol (CWMP) so that they can control and update the router remotely. However, I view every open port as a potential security risk, so here are some instructions should you wish to close it.

Before you start, check to see if port 7547 is open.

1) Open a Command Prompt and telnet to 192.168.1.254 (Windows Vista and Windows 7 users without telnet, see bottom of page)

2) Log in with Username: SuperUser. The password is either O2Br0ad64nd or the serial number of your router printed on its underside (excluding the bit in brackets).

3) Paste in these lines (use the little icon at the top-left of the Command Prompt window in order to paste):

service system modify name=CWMP-S state=disabled
saveall
exit

At this point port 7547 should be closed to the internet. You can now check to see if port 7547 is closed.

Note: In order to open port 7547 again, repeat these instructions, but in step 3 use the commands:

service system modify name=CWMP-S state=enabled
saveall
exit

Special note for Windows Vista and Windows 7 users: telnet is not installed by default. Go to:

Control Panel > Programs > Turn Windows features on or off

Put a tick in "Telnet Client" and click "OK"