Understanding Carrier-Grade NAT and Its Impact on DNSFilter

What Is Carrier-Grade NAT?

Carrier-Grade NAT is a method used by Internet Service Providers (ISPs) to allocate private IP addresses to consumer devices like modems, routers, and mobile phones. This approach is common, especially among wireless and cellular ISPs, due to the limited availability of public IPv4 addresses.

How It Affects DNSFilter

If your ISP uses Carrier-Grade NAT, you may run into problems when trying to set up DNSFilter. This is because your public IP address, which is vital for directing your DNS queries to DNSFilter, can change frequently. Additionally, ISPs using this method are likely to use transparent Proxying, another technique that can prevent your DNS queries from reaching DNSFilter.

Solutions

VPN

One workaround is to use a VPN (Virtual Private Network) to channel either all your traffic or just your DNS queries to another location not restricted by Carrier-Grade NAT. This can be particularly helpful if you're using a wireless network as a backup ISP.

Roaming Client

If your setup consists entirely of Windows-based computers, you could install our Roaming Client. This solution bypasses the need for a stable public IP address to connect to DNSFilter.

Change ISP

If feasible, consider switching to an ISP that doesn't use Carrier-Grade NAT. This will provide you with a stable, public IP address, making it easier to set up and use DNSFilter.