You finally get your new connection set up, load up your favourite game, and see the dreaded words: NAT Type Strict. Voice chat fails, you cannot host a lobby, and joining friends takes three attempts. Your speed test looks perfect, so what is wrong?
Very often, the answer is CGNAT — a technology most gamers have never heard of until it breaks something. It is increasingly common on new internet providers, mobile broadband, and satellite connections, and it quietly changes how your connection appears to the rest of the internet.
This guide explains what CGNAT is in plain language, how to check whether your provider uses it, exactly how it affects gaming, and the realistic ways to get around it.
Quick Answer
CGNAT means your provider shares one public IP address between many customers, so your router never gets its own public address. Speeds are unaffected, but you cannot open ports, host game servers, or accept incoming connections, which often causes Strict NAT, failed voice chat, and matchmaking problems. The usual fixes are asking your provider for a public or static IP, or using a VPN or IPv6 where available.
What CGNAT Actually Is
Every device on the internet needs an IP address. The older IPv4 system has about 4.3 billion addresses, and the world ran out of spare ones years ago. Normal NAT, the kind inside your home router, lets all your devices share your one public address. CGNAT — Carrier-Grade NAT — adds a second layer: your provider’s network does the same trick again, sharing one public address between dozens or even hundreds of customers.
As the technical overview of carrier-grade NAT explains, providers do this to stretch their limited pool of IPv4 addresses across a growing customer base. From the internet’s point of view, you and your neighbours sharing that address all look like the same connection.
Why providers use it
Buying more IPv4 addresses is expensive, and some newer providers — especially mobile, wireless, and satellite networks built recently — never owned many addresses to begin with. CGNAT is cheap, invisible for browsing and streaming, and lets a provider launch service without waiting for addresses. The problems only appear when something needs to reach you from outside.
How to Tell If You Are Behind CGNAT
You do not need to guess. There are two simple checks that take two minutes.
- Log in to your router’s admin page and find the WAN or Internet IP address shown in its status section.
- If that address falls in the range 100.64.0.0 to 100.127.255.255, you are definitely behind CGNAT — that block is reserved for it.
- Addresses starting with 10, 172.16 to 172.31, or 192.168 on the WAN side also indicate a private address rather than a public one.
- Search online for “what is my IP” and compare the result with your router’s WAN address. If they are different, some form of CGNAT or double NAT sits between you and the internet.
If both addresses match and the address is not in the ranges above, you have a genuine public IP and CGNAT is not your problem. Our guide to checking your router’s key settings shows where to find the WAN status page on most common routers if you get stuck.
How CGNAT Affects Online Gaming
Gaming traffic is mostly outgoing, which is why many games still work fine behind CGNAT. The trouble starts with anything that needs an incoming connection to reach your console or PC.
Strict NAT and failed connections
Consoles report NAT type based on how easily other players can connect to you. Behind CGNAT you will almost always see Strict or Type 3, because port forwarding on your own router only opens the first layer — the provider’s layer above it stays closed. Symptoms include being unable to host lobbies, voice chat that connects to some friends but not others, longer matchmaking, and being kicked from peer-to-peer games.
Port forwarding and hosting simply do not work
If you run a Minecraft, Valheim, or Plex server for friends, CGNAT blocks it completely: there is no public address for your friends to connect to. The same applies to remote access to home cameras and some work VPN setups. No router setting can fix this, because the block is at the provider’s network, not in your home — the port forwarding techniques described in Cloudflare’s explanation of how port forwarding works assume you control the outermost router, which CGNAT takes away.
What CGNAT does not affect
It is equally important not to blame CGNAT for everything. It does not reduce your speed, does not add meaningful latency by itself, and does not affect streaming, downloads, or browsing. If your ping is high or your speed is low, look elsewhere — CGNAT is specifically a connectivity and hosting problem, not a performance one.
Ways to Get Around CGNAT
Ask your provider for a public or static IP
This is the cleanest fix. Many providers will move you off CGNAT if you ask, sometimes free, sometimes for a small monthly fee for a static IP add-on. Business packages almost always include a public address. When you call, use the exact term — ask: “Can you assign me a public IPv4 address instead of a CGNAT address?” Support agents know precisely what that means.
Use IPv6 if your provider offers it
IPv6 addresses are so plentiful that no sharing is needed. If your provider, router, console, and the game all support IPv6, connections can bypass the CGNAT problem entirely. Support is still inconsistent across games and platforms, so treat this as a bonus rather than a guaranteed fix.
Use a VPN with port forwarding — carefully
A VPN gives you a tunnel to a server with a public address, and a few VPN services still offer port forwarding through that tunnel. This can restore an Open NAT, but it adds latency and costs a subscription, so it is a workaround for dedicated gamers rather than a first choice. Test the added ping before committing.
Switch provider or connection type
If gaming and hosting matter to you and your provider will not offer a public IP, that is a legitimate reason to switch at contract end. Before signing with anyone new, ask the CGNAT question directly — established fibre and cable providers in many areas still give every customer a public IPv4 address by default.
Common Mistakes to Avoid
The classic mistake is spending hours configuring port forwarding, DMZ, and UPnP on your router when the block sits at your provider — diagnose CGNAT first with the WAN address check. Another is buying a second router to fix “double NAT” that is actually CGNAT; your home setup is not the cause. Do not assume a VPN automatically helps either: most VPNs do not offer port forwarding at all. Finally, avoid signing a long contract for gaming without asking about CGNAT, especially with new, mobile, or satellite providers where it is most common.
Conclusion
CGNAT is your provider sharing one public IP address between many customers to save scarce IPv4 addresses. It leaves speed and streaming untouched, but it breaks port forwarding, hosting, and peer-to-peer gaming features, leaving you with Strict NAT no router setting can cure. Check your WAN address to confirm it, then ask your provider for a public IP — that single request solves the problem completely for most gamers.
Frequently Asked Questions
Does CGNAT increase my ping or reduce my speed?
No. CGNAT itself adds negligible delay and does not limit your bandwidth. High ping or low speed on a CGNAT connection has another cause, such as Wi-Fi quality, congestion, or a long route to the game server. CGNAT only affects incoming connections and NAT type.
Can I fix Strict NAT caused by CGNAT with router settings?
No. Port forwarding, UPnP, and DMZ settings on your router only control your own layer of NAT. The provider’s layer above it remains closed to incoming traffic. The real fixes are a public IP from your provider, IPv6 where it works end to end, or a suitable VPN.
Which providers are most likely to use CGNAT?
It is most common on mobile broadband, satellite services, newer alternative networks, and fixed wireless providers — networks built recently with few IPv4 addresses. Many large established fibre and cable providers still assign a public IPv4 address as standard, but policies change, so always ask before signing up.
Is CGNAT a security risk?
Not particularly. In one sense it adds a barrier to unsolicited incoming connections, but it is not a security product and should not be relied on as one. The shared address can occasionally cause unrelated problems, such as an IP-based ban or a rate limit triggered by another customer sharing your address.
Will CGNAT affect working from home?
Mostly no — email, cloud apps, and standard company VPNs that connect outward work fine. It can affect setups where IT needs to connect into your machine, some older VPN configurations, and self-hosted services. If your job depends on remote access, mention CGNAT to your IT team early.
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