Incomplete IP Addresses
By far, the most common reason for a failure to connect to our service is that there is insufficient IP address information. DNSFilter operates a closed DNS network. Unlike Google and Cloudflare, we do not answer DNS traffic from unknown networks.
This means that all IP addresses for your network must be put in the DNSFilter dashboard. If you get to a page similar to the screenshot below, it means that we are receiving this traffic from an unknown network. Check and make sure all IP addresses are accounted for. This includes:
- All primary external IP addresses
- Secondary addresses on another ISP
- Failover WAN links
A Transparent Proxy that is intercepting your DNS traffic and sending it somewhere else. This could be a local firewall/security appliance on your network, or an Internet Service Provider proxy.
This will be indicated by an error message
We are unable to service your request. In order to access the Internet, please log in to your content filtering dashboard or contact support to resolve this issue.
Verify Public IP Address
Verify that your public IP is properly entered into your network in the dashboard. You can do this by visiting Whatismyip.com (usually accurate) or by entering the below command into your command prompt or terminal (higher accuracy):
nslookup myip.dnsfilter.com. 126.96.36.199
This command will echo back your IP address, as shown in the image below. Compare it to what is in your dashboard.
Verify DNS Server
The next step is to check who is resolving your DNS requests. This can be discovered by evaluating the output of the following command:
In the first response below, you can see that nslookup used the default DNS server, was dns1.dnsfilter.com. DNSFilter successfully responded to the query by listing the public IP address of the network that requested it.
In the second example below, the nslookup command used the default server of 188.8.131.52. This means that either DNSFilter was not configured as the default nameserver for this computer, or that requests are being intercepted.
Because only DNSFilter nameservers are aware of the domain myip.dnsfilter.com, the query was unsuccessful.
At this point, there are three things to check:
- Is this machine/network pointing to the Anycast IPs for DNSFilter.
- Are there Hardware/Software Conflicts?
- Is there Transparent Proxying by your ISP?
If you are receiving a page similar to what is displayed below, there is an issue with your account billing. Please contact us at firstname.lastname@example.org so that we can resolve the issue.