How to compare blocking across nearby Australian ISPs

Comparing what your broadband blocks with what fails next door can look like a simple A/B test. On Australia’s NBN, however, the retail ISP, access network, DNS resolver, router security features and a website’s geographic rules may all differ. A failed page therefore does not, by itself, prove that an ISP censored it.

This guide explains how to compare your home ISP's blocking with a neighbouring ISP's while keeping those variables under control. The most useful neighbour is not merely another Australian provider: it is a consenting household nearby using a different retail service over comparable infrastructure.

Net Neutrality Monitor offers a useful evidence layer. It tracks filtering by ISPs and DNS servers, publishes country reports and blacklist, probe, DNS and statistical data, and lets users submit URLs or IP addresses for monitoring. Its results are indicative rather than definitive, especially while the volunteer-supported project remains in beta.

Build a fair side-by-side baseline

Start by recording the commercial ISP on each connection, not merely the infrastructure provider. In many Australian homes, NBN Co supplies the shared access network while Telstra, Optus, TPG, iiNet, Aussie Broadband or another reseller supplies the retail service. Neumon’s analysis of country-level probing patterns also shows that measurement density varies by country, so a missing report needs careful interpretation.

A fair baseline needs the same conditions recorded at both homes:

Condition	Home connection	Neighbouring connection	Why it matters
Retail provider	Record the service name	Record the service name	Separates retail filtering from shared infrastructure
Access technology	NBN FTTN or FTTP	The same type, if possible	Avoids comparing fixed fibre with wireless
DNS resolver	ISP-supplied address and any router override	Record the same details	Resolution differences can resemble transport blocks
Browser and security	VPN and DoH off; matching filters	Identical configuration	Controls for settings outside the ISP
Destinations and timing	Three fixed URLs or IPs at set times	Identical sequence and timing	Reduces CDN and time-of-day effects

If these conditions differ, the result describes the pair of configurations rather than one ISP in isolation. Match access type, resolver, device, request order and time as closely as practical.

Choose a genuinely comparable neighbour

Ideally, ask a mate in the next street to test the same destinations from a different retail ISP, ideally over comparable NBN infrastructure in a metro area such as Sydney, Melbourne, Brisbane, Perth or Adelaide. Ask for their ISP and access type rather than inferring it from the NBN box or Wi-Fi network name.

Nearby is useful, but geography has limits. An iiNet NBN service in a neighbouring suburb may use different backhaul and remote DNS infrastructure from your Optus line. A regional fixed-wireless or Starlink service is a weaker comparator than a like-for-like NBN connection because fixed wireless depends on local tower capacity and satellite routing adds a very different path.

Both households need permission for the test, and neither should inspect unrelated traffic. The comparison is reproducible when the neighbour follows the same steps on the same device settings and test schedule. If that cooperation is unavailable, published probes can still reveal patterns, but they cannot establish what happened inside a particular home.

Run matched checks from both homes

Choose a government service, a stable publisher and one ordinary commercial page as test destinations. A page showing keno 2 spot odds illustrates the caveat: if it opens on one line and not the other, state or territory rules, CDN routing or account controls may be responsible before ISP filtering is considered.

Complete the same short checklist at each location:

At your home

• Record the retail ISP, NBN or fixed-wireless type, router model and DNS resolver.
• Turn off VPN, browser DoH and relevant security filters for the test, unless one is the subject of the comparison.
• Load each destination twice in a private window and record the exact status, error text and time.

At the neighbour’s home

• Confirm the same device, browser, destination order and test window.
• Obtain explicit permission before recording or submitting any household data.
• Keep screenshots and raw error messages, but exclude unrelated browsing history.

Repeat the run at several times of day. Cached responses, transient CDN nodes and busy evening routes can resemble deliberate filtering, particularly around Australia’s peak evening broadband use.

Distinguish DNS, IP and HTTP failures

The error type narrows the diagnosis. A DNS refusal or NXDOMAIN points first to name resolution; a TCP or TLS timeout can indicate routing or transport interference; an HTTP 403 or 451 usually comes from the origin server, CDN or an intermediary policy. Browser messages often compress several of these into the same “cannot reach this page” wording.

Test the hostname through the supplied resolver, then repeat with one known public resolver while leaving other settings unchanged. This suggests a name-resolution or DNS-policy difference but does not prove that the retail ISP blocks the destination. Testing an IP address also needs the original hostname in the request so the server knows which site you mean; omitting it can create a false block.

Collect only the minimum useful data. A privacy-preserving contact tracing review offers a useful parallel: systems handling movement records need a clear boundary between identifying information and operational need. A diagnostic log similarly needs the destination, resolver and error, not a household’s complete browsing history. DoH and DoT can further alter what an ISP can inspect, so record whether each was enabled.

Read the evidence at the right level

Commercial content can change without any network intervention. For example, current casino bonuses may differ by Australian state or territory, account status, advertising campaign or CDN edge. A branded block page is more probative, but it should still be checked against the site’s policy and the resolver used.

In Australia, legal site-blocking orders and industry enforcement processes can form part of the access path. A failure may reflect compliance with such a process rather than an ISP’s discretionary policy. Use Net Neutrality Monitor to submit the URL or IP address, then compare its country-specific result with probe, DNS, blacklist and statistical records. Look for the same destination failing from several independent networks and with the same error.

The service is volunteer-supported, powered by AirVPN and presented as a beta project for indicative research. That status is important: cite the observation with its timestamp and conditions rather than labelling an ISP as a censor without corroboration. Reproduce the failure on another connection and inspect the technical error before making that claim.

Preserve and repeat the comparison

Record the timestamp with AEST or AEDT, suburb, retail ISP, access technology, DNS resolver, device, browser, enabled privacy controls and the exact URL or IP tested. Note whether the failure was a DNS error, timeout, TLS failure or HTTP response. These fields make the result useful when an NBN or provider configuration later changes.

Treat a difference as meaningful when it repeats under matched conditions and appears across more than one network path. Treat it as inconclusive when a router filter, alternate resolver, commercial geofence or one-off outage can explain it. The goal is a defensible comparison, not a dramatic verdict from one browser error.

Schedule the next matched run for 30 days after the baseline, using the same three destinations and device settings, and file the timestamped results beside the original set.