Unlocking a Vodafone AU (Huawei) K4203 3G modem


These neat little modems are already unlocked, but don’t automatically connect to non-Vodafone networks. They also need the other network’s APN configuration to access the internet. In order to connect, we need to manually set these up.

When plugged in, the modem menu is at Make sure you aren’t connected to another network.

To access the settings menu:

  1. Navigate to to open the modem menu
  2. click QuickStart on the main menu bar
  3. then Network on the side menu
  4. Under Preferred Network, press Search
  5. Select the right network for your sim
  6. You should now see a signal strength indicated on the right side panel. We are now going to set up the APN:
  7. click Connection on the side menu
  8. Change Account type to Custom
  9. Leave IP type alone
  10. Set the IP APN to your APN name, eg: YESINTERNET for Optus and Virgin, telstra.internet for Telstra, etc. a full list is available at: https://whirlpool.net.au/wiki/mobiles_apn
  11. IP Number according to the above whirlpool link, the number for all services in Australia is *99# (additional note below)

This worked for me. There are many of these available and they still work well (2018). These instructions are the same for other Huawei usb modems of a similar vintage (K606, etc.)


  1. user qoqqqq states in the comments on https://www.ozbargain.com.au/node/175436:
    IP4/IPV6 Number = 1234 or *99#( possible any random number might work)
    all other settings left blank.
  2. I found that 1234 worked fine as my IP Number


iinet Technicolor TG789vac v2 NBN modem can’t connect to DynDNS service

Note: I use specifically dyndns.org (now dyn.com), this may or may not effect other services.

When setting up the modem’s dynamic dns updater, I kept getting status: bad auth

I triple checked the authentication details and tried both https on and off.

In the end I had to change the password on my dyndns account to one with no special characters.

Also: The modem only supports one dyndns domain/service. This is unfortunate if you want to keep a few updated to stop them expiring.