- Compatible with:
- Windows,
- macOS
- Available in:
- Desktop Security version 5,
VPN version 5
How this issue affects you
Your VPN can't connect to a server on a macOS or Windows device and the error message below displays:
MB404104: Unable to connect to VPN server. Check your network connection and try again.
What caused this issue
A double NAT (Network address translation), where internet data goes through the NAT process twice, can cause communication issues between Privacy VPN and servers. Internet service providers (ISPs) provide a modem or gateway, a modem and router combo, that is set up to perform NAT. A double NAT happens when another router is connected to the ISP modem or gateway, which may impact VPN functionality, online gaming, and communication between devices connected to your network.
How to resolve this issue
If you determine you have double NAT, contact your Internet Service Provider for help. Follow the steps below to check if you have double NAT.
Check if you have double NAT
Windows
- On a Windows device connected to the Internet, click the Start menu.
- Type cmd, then hit Enter/Return.
- Type tracert 8.8.8.8. This performs a traceroute to Google’s DNS server.
- Compare the first two IP addresses listed to the private IP address ranges listed below.
If the first two IP addresses listed are private, you have double NAT.
Mac
- On a Mac device connected to the Internet, open the Terminal or Terminal.app.
- Type traceroute 8.8.8.8. This performs a traceroute to Google’s DNS server.
- Compare the first two IP addresses listed to the private IP address ranges listed below.
If the first two IP addresses listed are private, you have double NAT.
Private IP address ranges
Private IP addresses are within one of the following ranges:
IPv4 private address ranges (RFC 1918):
10.0.0.0 – 10.255.255.255 (24-bit block)
172.16.0.0 – 172.31.255.255 (20-bit block)
192.168.0.0 – 192.168.255.255 (16-bit block)IPv6 private address ranges:
fc00::/7 address block = RFC 4193 Unique Local Addresses (ULA)
fec0::/10 address block = deprecated (RFC 3879)