[SOLVED] basic question about ip address

brannsiu

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Hi. I know that two different computers at different locations could have the same IP address.
How about getting online with a mobile device through cellular network? Does it also contain an IP
address with format like that of computer through broadband? Could two mobile devices getting online
through cellular network have same IP address too?

If a mobile device gets online with shared WiFi from a desktop PC, does it have the same IP address as that of the PC?
 
Solution
Hi. I know that two different computers at different locations could have the same IP address.
How about getting online with a mobile device through cellular network? Does it also contain an IP
address with format like that of computer through broadband? Could two mobile devices getting online
through cellular network have same IP address too?

If a mobile device gets online with shared WiFi from a desktop PC, does it have the same IP address as that of the PC?
You have to remember there are two kinds of IP addresses, public and private. The WIFI router gets a public IP address and creates private addresses for all the WIFI devices. All the WIFI devices traffic is translated by the NAT function to and from the same public IP...

kanewolf

Titan
Moderator
Hi. I know that two different computers at different locations could have the same IP address.
How about getting online with a mobile device through cellular network? Does it also contain an IP
address with format like that of computer through broadband? Could two mobile devices getting online
through cellular network have same IP address too?

If a mobile device gets online with shared WiFi from a desktop PC, does it have the same IP address as that of the PC?
You have to remember there are two kinds of IP addresses, public and private. The WIFI router gets a public IP address and creates private addresses for all the WIFI devices. All the WIFI devices traffic is translated by the NAT function to and from the same public IP address.
 
Solution

brannsiu

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You have to remember there are two kinds of IP addresses, public and private. The WIFI router gets a public IP address and creates private addresses for all the WIFI devices. All the WIFI devices traffic is translated by the NAT function to and from the same public IP address.

Is "private" address never seen by the remote side? All devices under the same WIFI router will have same IP address (i.e public address) seen by the remote side? Am I correct
 

brannsiu

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Correct, the private IP address is only seen by the router.
Also correct, the remote device sees a single public IP address for any devices connected to the router.

What is the format of IP address if it is through cellular network (i.e. not WiFi and not broadband). Is it the same as other IP or does it look different? Could two different mobile devices from two unrelated people have identical IP address seen by the remote side? (I know that two different desktop/laptop computers at two different locations could have same IP address seen by remote side)
 

kanewolf

Titan
Moderator
What is the format of IP address if it is through cellular network (i.e. not WiFi and not broadband). Is it the same as other IP or does it look different? Could two different mobile devices from two unrelated people have identical IP address seen by the remote side? (I know that two different desktop/laptop computers at two different locations could have same IP address seen by remote side)
It depends on the cellular provider. Some use IPv6 and provide a public IP address. Some use Carrier NAT and provide a private IPv4 address.
All devices have to be unique, assuming everything is configured correctly. Otherwise there is no way for your web response traffic to get back to your device.
 
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brannsiu

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It depends on the cellular provider. Some use IPv6 and provide a public IP address. Some use Carrier NAT and provide a private IPv4 address.
All devices have to be unique, assuming everything is configured correctly. Otherwise there is no way for your web response traffic to get back to your device.

But I know that desktop one may have same IP address for different desktops, is it true? In that case how web response traffic to get back to PC? Does PC connected to broadband work differently than mobile devices through cellular network? Thx
 

kanewolf

Titan
Moderator
But I know that desktop one may have same IP address for different desktops, is it true? In that case how web response traffic to get back to PC? Does PC connected to broadband work differently than mobile devices through cellular network? Thx
Many devices can have the same private address. You need to read about "NAT" to understand how two PCs could have the same private address.
Broadband and cellular follow the same basic rules since they have to be able to interact.
 
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