ipFormat and capacity
IPv4 has a 32-bit address space and IPv6 has a 128-bit space. IPv4 usually appears as dotted numbers; IPv6 uses colon-separated hexadecimal groups. IPv6’s larger space reduces the pressure for address sharing common with IPv4, although individual networks can still have different designs.
Both can operate together
On a dual-stack connection, a device can use both protocols. One site may load over IPv4 while another loads over IPv6. Two IP-detection services showing different addresses is therefore not automatically a fault. First check whether their results represent the same protocol.
A troubleshooting approach
If only some sites fail, inspect the address family, DNS answers, and routing separately. Identify the failing path rather than permanently disabling IPv6 as a first step. Compare performance against the same destination at similar times; the protocol name alone cannot predict latency.
Two sites showing different IPs
When one service shows dotted IPv4 and another shows colon-separated IPv6, record the protocol difference first. One connection may use both families. Compare results within the same family without changing the VPN or network. A correct IPv4 location and different IPv6 location can reflect separate database records rather than a device fault.
Further reading
IPv6 specification — RFC 8200 ↗Put it into practice
Inspect one public IP, or compare a list of addresses with the bulk lookup tool. Location results are approximate.
Single lookup ↗ Bulk lookup ↗