2021-05-06 18:46:45
Network routing
, 2021-05-06 18:46:45

2 small questions about the external IP address?

1) How to distinguish external gray from white IP? 2) I have an external IP, but on my router I get an IP from the provider from the 10.x.x.x range and everything works: VPN channels and other services that require an external white IP - how is this possible?

Answer the question

In order to leave comments, you need to log in

4 answer(s)
akelsey, 2021-05-06

1) Public IP (aka white, as it is called only in Russia) - an address to which there is a route to the Internet from other devices - it can be:
* dynamic, when the provider issues an address from the pool of public addresses, a new one is issued each time you reconnect. Usually free. For such addresses, cunning and economical - the DynDNS service was invented - many people live and rejoice like that, they can connect to their services from anywhere in the world (RDP / SSH / VPN) - but for mail, for example, this option does not work (although with current automation services and if the mail is not a critical service, you can also cast scripts - for example, cloudflare has an API that allows you to modify DNS - and cloudflare sends changes to the world very quickly).
* static, you pay the provider - he assigns 1 dedicated public address to you.
A "gray" address is when clients are in a subnet that is not routable from the Internet, and go through a legal crutch called NAT through one gateway (through which external address the packets will go to the world - the provider decides).
2) It is likely that the provider simply maps some kind of Public IP assigned to you to the addresses given to you in the 10.x.x.x subnet.
To distinguish, you need to "open the port", i.e. raise any service that listens on a specific port, and make sure on your router that it is 100% open and correctly forwarded (if the service is not raised on the router, but on the device behind the router) - the simplest option is any smtp server, or http server (preferable) then you can for example, on 2ip.ru to find out how the Internet sees you, and already find online telnet and try to connect to this address. If success - then this address is public -) (why http is preferable, because many online telnet services forbid telnetting to port tcp/25 - so that the villains do not send spam.)

CityCat4, 2021-05-06

How to distinguish external gray from white IP?

No way. There are no "outer grays". Gray addresses operate only within the provider's local area and are required to be silenced when they are routed out (although, of course, it is not a fact that they do this). Any address defined in RFC1918 can be used by anyone, anywhere and any number of times (but they must be silenced when routing).
I have an external IP, but on my router I receive from the provider an IP from the range 10.x.x.x and everything works

Normal practice - the provider issued a gray address. And "everything works" because this address is natitsya in some kind of white by the provider. Go to 2ip.ru (2ip.ua are different sites!) - and be surprised :)

Vasily Bannikov, 2021-05-06

1) How to distinguish external gray from white IP?

If someone other than you is sitting on your IP, then it is gray.
You can do a tracert and check.
White IP is needed only by the server, but not by the client

Vladimir Pilipchuk, 2021-05-16

Outer/white/gray/bogon are all conventions. These are non-globally routable subnets of a different class. The official list of subnets is described in RFC6890, RFC5735 and some others.
Here is a complete list of such subnets:
198.51.100 24

I have an external IP, but on my router I get an IP from the provider in the 10.x.x.x range and everything works ...

In this case, most likely NAT 1:1 takes place, in which all packets that come to your "white IP" are forwarded to your interface with a "gray" address. This is what many cloud (and not only) providers do.

Didn't find what you were looking for?

Ask your question

Ask a Question

731 491 924 answers to any question