What is NBN port locking and how to fix it

Krishan Sharma 18 July 2017 NEWS


If you try and access the NBN through an incompatible modem, your port could be locked. Here's what that means and how to fix it.

Over 50 percent of Australians will be connected to the NBN network via a Fibre-to-the-node (FTTN) connection under the Coalition’s multi-technology mix program. While Fibre-to-the-premises (FTTP) and NBN’s satellite customers can simply plug in their existing router to wirelessly share their Internet connection throughout their home, FTTN customers will generally require a new modem before they can connect to their Internet service.

NBN Co has a specific set of requirements and features that a modem must meet in order for it to connect to the FTTN network. This means that if you want to enjoy all the benefits of a super-fast FTTN connection, you need the right modem for the job. If the NBN network detects an incompatible modem, your ports could potentially become locked.

Port locking is an NBN network restriction that is placed on the particular FTTN service in order to prevent network instability. When an NBN connection tries to run through an incompatible modem, the system goes into panic mode and locks the ports in order to not degrade the network or cause issues for other users on the network.

Broadband Offer

TPG NBN Fast Bundle Unlimited 50/20 Mbps 1 Month



Min. Total Cost of $199.94

Provider Logo


50 Mbps

Download Speed

What do I do if my port is locked?

Port locking effectively stops the FTTN connection from working at a network level and the customer will need to contact their ISP to unlock it, a process which can take up to 48 hours. This leaves the customer without an active Internet connection, and the port will not automatically unlock by simply connecting a different modem.

Once the port has been unlocked, you should check with your ISP or modem manufacturer to see whether the model modem you are using is compatible with NBN’s FTTN service to prevent the same issue occurring again. Some VDSL/VDSL2 compatible modems may simply require a firmware update to get up and running on NBN’s FTTN service.

How do I avoid port locking?

The sure-fire way to avoid port locking is to purchase an FTTN-ready modem from your ISP. The problem with ISP-supplied modem routers is they are often quite limited in their functionality and often don’t deliver the maximum potential speeds you could be receiving when compared to some other third-party modem routers you can buy in stores.

Unfortunately, NBN Co will not publicly disclose the models that have been whitelisted and not all manufacturers specifically state FTTN compatibility on the box. Typically, if a modem router supports VDSL or VDSL2, then it should work with an FTTN service. However, there’s still the risk that the modem might not support all of the required NBN features or have them enabled from the outset, which will result in the port being locked. This can make shopping for one a needlessly confusing affair.

Remove the confusion from the equation by consulting our modem router review round-up where we tested most of the VDSL/VDSL2 compatible models available at retail on an active FTTN connection. During the test period, we came across a couple of models that locked our ports and we also documented how we were able to eventually get around those issues.

Additionally, we recorded the Internet connection speeds that we were able to achieve with each model and the ease in which we were able to secure an active Internet connection from the initial set-up process. The results of our tests shed light on not only the models that provide a hassle-free experience but also highlight the ones that will get the best possible speeds from your FTTN connection.

Latest Broadband news

The latest broadband offers on finder

Ask an Expert

You are about to post a question on finder.com.au:

  • Do not enter personal information (eg. surname, phone number, bank details) as your question will be made public
  • finder.com.au is a financial comparison and information service, not a bank or product provider
  • We cannot provide you with personal advice or recommendations
  • Your answer might already be waiting – check previous questions below to see if yours has already been asked

Finder only provides general advice and factual information, so consider your own circumstances, or seek advice before you decide to act on our content. By submitting a question, you're accepting our Terms and Conditions and Privacy Policy.

2 Responses

  1. Default Gravatar
    GalahadOctober 30, 2017

    Can you suggest any reasonably priced VDSL2 modem only? I have a good setup LAN including a Router with automatic WAN backup – switching to 3G/4G, local Wi-Fi network and VoIP. I need just the Modem, to allow me to change to the NBN, which is available now.

    • finder Customer Care
      RenchOctober 31, 2017Staff

      Hi Galahad,

      Thanks for your inquiry.

      You can have a look on this page and compare your options for NBN routers/modem with VOIP. You can also get helpful tips on this page on how to switch to NBN.

      Hope this information helped.


Ask a question
Go to site