An IP address is a unique identifier for a device on the internet or a local network. Without it, data cannot find its way between computers, servers, and phones.
What Is an IP Address?
IP stands for Internet Protocol. The address says where a device sits, the way a postal address says where a house is.
Two versions are in use today: IPv4 and IPv6.
IPv4: The Classic Standard
IPv4 was the first version and remains the most common.
- The address is 32 bits long.
- About 4.3 billion unique addresses exist.
- Format: four numbers from 0 to 255 separated by dots, such as
192.168.1.1.
Example: 8.8.8.8, one of Google’s public DNS servers.
Limit: device growth exhausted IPv4 addresses long ago, which pushed the move to IPv6.
How an Address Is Built
An IPv4 address splits into a network part and a host part. The subnet mask marks the border. In a home network 192.168.1.0/24, the first three numbers name the network and the last one goes to a device.
Private ranges 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 never reach the internet; they live inside an office or a flat. The provider assigns the public address, and it can change.
IPv6: The Modern Protocol
IPv6 solves the address shortage.
- The address is 128 bits long.
- It allows 340 undecillion addresses, or 340 with 36 zeros.
- Format: eight groups of hexadecimal numbers separated by colons, such as
2001:0db8:85a3:0000:0000:8a2e:0370:7334.
Long addresses get shortened: a run of zero groups becomes ::. The same address reads as 2001:db8:85a3::8a2e:370:7334.
IPv6 advantages:
- Enough addresses for any future scale.
- More efficient routing.
- Built-in security and mobile support.
NAT and Why Addresses Last
NAT keeps IPv4 alive: dozens of devices share one public address while the router rewrites addresses on the fly. For a site, that means one IP can hide a whole network.
IPv6 rarely needs NAT, because every device can have its own address. Blocking a single IPv6 address is therefore more precise than blocking an IPv4 one.
The Main Differences
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits (4 bytes) | 128 bits (16 bytes) |
| Format | Decimal, dots | Hexadecimal, colons |
| Address count | ≈4.3 billion | ≈340 undecillion |
| NAT | Common | Usually not needed |
| Security | Optional (IPsec) | Built-in IPsec support |
Why It Matters
IPv4 and IPv6 run side by side, but not every device speaks both. Old hardware sees only IPv4. Modern services and security tools, BotBlocker included, analyze both address types.
For a site owner this means the same visitor can arrive over IPv4 today and IPv6 tomorrow. Checks have to understand both records, or part of the traffic stays unexamined.
The address changes with the network: one at home, another at the office, a third on mobile data. Blocking by IP works for clear offenders, not for identifying a person over time.
FAQ
What is the difference between a public and a private address?
A public address is visible on the internet; a private one stays inside a local network.
How do I find my IP?
Use an IP lookup service, or the router settings if you need the address inside the network.
Why are there two IP versions?
IPv4 ran out of addresses, so IPv6 was created to expand the internet.
Will IPv4 disappear soon?
No. Both versions will stay in use for years; the move to IPv6 is slow.
Does BotBlocker support IPv6?
Yes, every check works with IPv4 and IPv6 addresses.
Can I block an IPv6 address?
Yes. It goes into the blacklist the same way an IPv4 address does.
What is NAT in plain words?
A way to share one public address across many devices through a router.