IPv4
IPv4 is the main IP address format on the internet: four numbers from 0 to 255 separated by dots.
Updated · Prokso editorial team
An IPv4 address looks like 203.0.113.5: four numbers, each from 0 to 255. There are just over four billion such combinations in total, and free addresses ran out long ago.
Because of the shortage, ISPs share one external IPv4 address among many subscribers. This is how NAT and CGNAT work. At the same time, a new format is being rolled out: IPv6.
For working with websites, IPv4 is still the main format: every site and program accepts it. That is why proxies with IPv4 addresses suit any task without extra checks.
The My IP page shows which IPv4 address websites see right now. If you open it through a proxy, it will show the proxy's address.
Which IPv4 addresses websites never see
Some IPv4 ranges are reserved for internal networks. Millions of devices use these addresses at the same time, and they never go out to the internet. If a program shows one of them as "your IP", it is a local address, not the one a website sees.
| Range | Where you meet it |
|---|---|
10.0.0.0/8 | office and ISP networks |
172.16.0.0/12 | corporate networks, Docker |
192.168.0.0/16 | home routers |
100.64.0.0/10 | carrier CGNAT |
127.0.0.0/8 | the computer itself (localhost) |
How to check which address a website sees through a proxy
Open the My IP page first without a proxy and then with one. The page shows the IP, its version, the country and the ISP. Through the proxy the address should change, and the country should match the one written in the username, for example cr.de.
If you see IPv6 without the proxy and an IPv4 from another country with it, that is fine: the website gets the proxy exit address, not yours. The warning sign is different: your own address of any version still showing after the proxy is on. To be sure, reload the page a few times: on port 823 the address is different each time, while on a sticky port it stays the same.
Typical mistakes when writing IPv4
The Prokso IP whitelist takes the external address of your computer, the one the My IP page shows without a proxy. A 192.168.x.x address from your Wi-Fi settings will not work there. You can add up to 5 addresses per plan.
Do not write leading zeros: some programs read 203.000.113.005 as an octal number and connect to a different address. Extra spaces in a string like gw.prokso.com:823 also cause an error. Access without a username is covered in the IP whitelist article.
FAQ
Will IPv4 addresses run out?
There are almost no free blocks left in the registries, but addresses are resold and shared through NAT. So IPv4 will remain the main format for a long time.
Is an IPv4 proxy suitable for any website?
Yes, every website accepts IPv4. This is not always the case with IPv6.
Related terms
Residential $1.59, mobile $2.50, datacenter $0.65 per GB
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