How to change your modem login security details Belong 4353 modem By default, the admin login password is ‘Belong’ If you wish to change your modem’s admin password, make sure you are connected via Wi-Fi or Ethernet, then follow the steps below: First connection must be done with Optus supplied modem After that, can switch to BYO modem but MUST copy Optus Modem VDSL MAC Address to your modem MAC – Most modems support this feature. How do I set-up my Belong modem for services on the nbn™? Photos. for example my brother use a D-link router he has connected an external hard disk t. Belong 4353 modem review Selling Modems for different prices.