Every device on a network is reached through an IP address. Knowing which kind of address you have explains a lot: why your home PC shows a different IP than your router, why many websites can share one server address, and when paying for a dedicated IP is actually worth it.
Before you start
No tools are needed. If you want to see your current public address, open the MdmHost IP checker. For the difference between the two address formats, read IPv4 vs IPv6 explained alongside this guide.
What an IP address is
An IP address is a number that identifies a network interface so packets can be delivered to it. IPv4 addresses look like 203.0.113.25 (four numbers from 0 to 255); IPv6 addresses look like 2001:db8:85a3::8a2e:370:7334. Domain names exist so people do not have to remember these numbers: DNS turns example.com into an IP, as explained in how DNS resolution works.
Public vs private IP addresses
A public IP is routable on the internet and unique worldwide. A private IP is only valid inside a local network and is reused by millions of networks. These IPv4 ranges are reserved as private (RFC 1918):
| Range | Typical use |
|---|---|
10.0.0.0/8 | Corporate networks, cloud private networks, VPN tunnels |
172.16.0.0/12 | Docker bridge networks, office LANs |
192.168.0.0/16 | Home and small office routers |
100.64.0.0/10 | Carrier-grade NAT used by many mobile and fibre ISPs |
127.0.0.0/8 | Loopback: the machine itself (127.0.0.1) |
Your router uses NAT (network address translation) to let every device behind it share one public IP. That is why a website sees your router's public address, not your laptop's 192.168.x.x address.
Note: For IPv6 the equivalents are link-local addresses (fe80::/10) and unique local addresses (fc00::/7). Because IPv6 has so many addresses, most devices also get a public IPv6 address and NAT is rarely needed.
Static vs dynamic IPs
Home connections usually get a dynamic IP that can change when the router restarts. Servers use static IPs that never change, because DNS records point at them. If you need to reach a home device whose IP keeps changing, see Dynamic DNS in cPanel. To pin an address on a VPS, follow configure a static IP with Netplan.
Shared vs dedicated IP on web hosting
On shared and reseller hosting, many websites usually share one server IP. The web server reads the domain name the visitor asked for (the HTTP Host header and the TLS SNI field) and serves the right site. This is normal, secure and works with free SSL.
A dedicated IP belongs to one account only. It is useful when:
- You want your own reputation for outgoing email, independent of other accounts.
- A third party (payment gateway, API partner, office firewall) needs to whitelist one fixed IP that only you use.
- You run services that are reached by IP rather than domain name, such as some FTP or game setups.
- You resell hosting and want your own nameserver IPs to look independent.
A dedicated IP is not needed for SSL, and on its own it does not improve SEO or speed. MdmHost includes a dedicated IP with the top VIP Master Reseller plan; see Master Reseller hosting.
How to find the IPs involved
- Your own public IP: open /tools/ip-checker.
- Your website's server IP: in cPanel it is shown under General Information → Shared IP Address (or Dedicated IP Address), or run
dig +short example.com. - A VPS's addresses: run
ip -br addron Linux oripconfigon Windows.
dig +short example.com A
dig +short example.com AAAATroubleshooting
- The IP checker shows a different IP than my router page: your ISP probably uses carrier-grade NAT (a
100.64.x.xWAN address). Ask your ISP for a public IP if you need to host from home. - I was blocked by my server's firewall: give support the public IP from the IP checker, not a
192.168.x.xaddress. See unblock an IP blocked by Imunify360.