Which Australian ISPs use CGNAT?

As of August 2026: Optus uses CGNAT on all consumer NBN plans. Belong (a Telstra brand) uses CGNAT. Tangerine uses CGNAT but offers a paid static IP add-on. Aussie Broadband, Superloop, SpinTel, and Launtel use CGNAT by default but offer a paid static IP option. Telstra does NOT use CGNAT by default and offers static IP for ~$10/mo. Internode and iiNet do NOT use CGNAT. TPG is partial, depends on plan tier. Always verify with your ISP as policies can change.

Does NBN upload speed limit NAS remote access?

Yes, significantly. Even without CGNAT, NBN 100 gives 20 Mbps upload on FTTN/FTTB (up to 50 Mbps on the accelerated FTTP/HFC Home Fast II tier). This supports one 1080p Plex stream but not two simultaneous 4K streams. NBN 25 gives just 10 Mbps upload, marginal for Plex, better suited to file access only. If remote Plex is your primary use case, NBN 250 (50 Mbps upload) or NBN 1000 (100 Mbps upload) make a meaningful difference. Fixed wireless and satellite are especially limited.

NBN Remote Access Reality Checker: Can You Actually Access Your NAS Remotely?

Q: How do I check if I'm behind CGNAT?

Open a browser and search 'what is my IP', note the IP shown. Then check your router's WAN IP in its admin page (usually 192.168.0.1 or 192.168.1.1). If they match, you're probably not behind CGNAT. If your router's WAN IP falls between 100.64.x.x and 100.127.x.x (the 100.64.0.0/10 range), you ARE behind CGNAT. A WAN IP elsewhere in 100.x.x.x, e.g. 100.1.x.x or 100.200.x.x, is NOT CGNAT.

This NBN remote access reality checker determines whether you can reliably access your NAS from outside your home based on your ISP, NBN connection type, and CGNAT status. Identifies whether you need a VPN, Tailscale, or reverse proxy to work around restrictions.

Find out exactly what remote access methods will work (and won't) for your NBN connection, including whether you're blocked by CGNAT and what to do about it.

Most remote access guides assume you can forward ports. In Australia, that assumption is wrong for a large portion of NBN users. Optus, Belong, Aussie Broadband, Superloop, SpinTel, Tangerine and Launtel all use CGNAT by default on consumer plans (most offer a cheap static-IP opt-out), blocking traditional port forwarding until you pay for that opt-out. Telstra is a notable exception and does not use CGNAT by default. Even ISPs without CGNAT face upload speed limits that restrict what's practically usable.

This tool is a logic tree, not a calculator. It takes your NBN type, tier, and ISP, and tells you exactly what works, what doesn't, and which workarounds apply to your situation. See also our NAS Remote Access Guide for a full walkthrough.

Your Connection

NBN Technology Type

NBN Speed Tier

ISP (Internet Service Provider)

What do you want to do? (select all that apply)

Access files remotely from anywhere

Stream media (Plex / Jellyfin) remotely

Monitor NAS status and alerts

Use NAS as VPN server

Self-host web applications

Security cameras / NVR remote access

Sync / backup between sites

Your Verdict

Checking…

Use Case Verdicts

Select use cases on the left to see verdicts.

AU ISP CGNAT Status Reference

CGNAT (Carrier-Grade NAT) blocks traditional port forwarding. AU-specific, caused by NBN Co IPv4 scarcity policy. ISP CGNAT policies verified March 2026. Always verify with your ISP as policies can change.

ISP	CGNAT?	Static IP Available?	Notes
Aussie Broadband	Yes (confirmed)	Yes (~$5/mo)	CGNAT by default, but cheap static IP opt-out
Superloop	Yes (confirmed)	Yes (~$5/mo)	CGNAT by default, but cheap static IP opt-out
Internode	No (most plans)	Yes (~$10/mo)	Check entry plans
iiNet	No (most plans)	Yes (~$10/mo)	Owned by TPG, similar policy
TPG	Partial	Yes (premium)	Depends on plan tier
Telstra	No (by default)	Yes (~$10/mo)	Does not use CGNAT on consumer NBN
Optus	Yes (all consumer)	No	CGNAT on all consumer plans
Belong	Yes	No	Budget Telstra brand
Spintel	Yes (confirmed)	Yes (~$5/mo)	CGNAT by default, but cheap static IP opt-out
Tangerine	Yes	Yes (~$5/mo add-on)	CGNAT by default, static IP add-on available
Launtel	Yes (confirmed)	Paid opt-out (2 methods)	Tas-based; CGNAT by default, opt-out available

NBN Upload Speed & Remote Access

Plan	Upload Mbps	File Access	1080p Plex	4K Plex
NBN 25	10 Mbps	Limited	1 stream (tight)	No
NBN 50	20 Mbps	Good	2 streams	1 stream
NBN 100 (FTTN/FTTB)	20 Mbps	Good	2 streams	1 stream
NBN 100 (FTTP/HFC, accelerated)	50 Mbps	Excellent	5+ streams	2-3 streams
NBN 250	50 Mbps	Excellent	5+ streams	2-3 streams
NBN 1000	100 Mbps	Excellent	5+ streams	3+ streams
Fixed Wireless	5-20 Mbps	OK	1-2 streams	Limited
Sky Muster	5 Mbps	Very limited	No	No
Starlink	15-35 Mbps (~20 typical)	Good	1-2 streams	Limited

The single biggest limitation for AU NAS remote access is upload speed, not CGNAT. Even without CGNAT, standard NBN 100 (FTTN/FTTB) only gives 20 Mbps upload — accelerated FTTP/HFC NBN 100 now gives 50 Mbps. Use our Transfer Speed Estimator to assess your connection. Rates and CGNAT status verified August 2026.

Frequently Asked Questions

CGNAT (Carrier-Grade NAT) is how NBN providers share a limited pool of IPv4 addresses across many customers. When you're behind CGNAT, multiple households share the same public IP address, which means you can't forward ports to your NAS. This is why "just forward port 5001" doesn't work for many AU NBN users. Optus and Belong use CGNAT on all consumer plans (Telstra does not, by default). The 100.64.0.0/10 address range (100.64.x.x to 100.127.x.x) is the IANA-reserved CGNAT space, not all of 100.x.x.x. If your router's WAN IP falls in that specific range, you're behind CGNAT.

As of August 2026: CGNAT confirmed: Optus (all consumer), Belong, Aussie Broadband, Superloop, SpinTel, Tangerine, Launtel. No CGNAT: Telstra (does not use CGNAT by default), Internode (most plans), iiNet (most plans). Partial: TPG (depends on plan tier). Always verify with your ISP as policies change. Most CGNAT ISPs above offer a paid static-IP opt-out (~$5/mo for Aussie Broadband, Superloop, SpinTel and Tangerine); Telstra's own static IP costs ~$10/mo.

Tailscale is a P2P mesh VPN that works through CGNAT. It installs on your NAS and remote devices, creating an encrypted tunnel that bypasses port forwarding requirements entirely. It uses DERP relay servers (including one in Sydney) when direct P2P isn't possible. Free for personal use (6 users, unlimited devices, subject to tagged-resource limits). Works with Synology DSM 7 and QNAP QTS. It's the most recommended CGNAT workaround for AU home NAS users.

Yes. Significantly. Even without CGNAT, standard NBN 100 on FTTN/FTTB gives only 20 Mbps upload (the accelerated FTTP/HFC version now gives 50 Mbps). This supports one 1080p Plex stream but not two simultaneous 4K streams at the lower tier. NBN 25 gives just 10 Mbps upload: fine for file access, tight for streaming. If remote Plex streaming is your primary use case, NBN 250 (50 Mbps upload) or NBN 1000 (100 Mbps upload) make a meaningful difference. Fixed wireless and satellite are especially limited.

Yes. Synology QuickConnect and QNAP myQNAPcloud are cloud relay services built into the NAS OS. They work through CGNAT because the connection is outbound from your NAS to the vendor's servers. This works for file access, mobile apps, and monitoring. It tries LAN, then direct WAN, then hole punching first, and only falls back to routing through Synology's or QNAP's relay servers (slower) as a last resort. Requires a vendor account.

Open a browser and search "what is my IP" and note the IP shown. Then check your router's WAN IP in its admin page (usually 192.168.0.1 or 192.168.1.1). If they match, you're probably not behind CGNAT. If your router's WAN IP falls between 100.64.x.x and 100.127.x.x (the 100.64.0.0/10 range), you ARE behind CGNAT. A WAN IP elsewhere in 100.x.x.x is not CGNAT.

Related Tools & Guides

NAS Remote Access & VPN Guide (AU) → NBN Plan Finder → Small Business Storage Hub → Home & Family Storage Hub → Transfer Speed Estimator → NAS vs PC Cost Comparison → All Tools →