difference between public and private ip address

[bhuvaneshwaran]

hello,


can you tell me the difference between public and private ip address detail..

 

[andre_luis]

The same IP identifier may be present in several local networks, properly disjuncted from each other by routers, but in the global network, IP identifiers must be unique if a device is connected there.

 

[FvM]

Hosts with public IP can be connected through the internet, private IPs can't.

 

[ads-ee]

For a thorough explanation you can read the MS on the subject.

Basically it boils down to any address that starts with 10.xx.xx.xx, 172.16.xx.xx, or 192.168.xx.xx is private and will never exist on the public network and won't be routed anywhere. The reset of the IP addresses (other than broadcast) are public and should not be used in a local network.

 

[andre_luis]

Basically it boils down to any address that starts with 10.xx.xx.xx, 172.16.xx.xx, or 192.168.xx.xx is private and will never exist on the public network

Interesting to see that do not make mention to the predefined localhost IP, 127.0.0.1.

 

[ads-ee]

Yeah, I probably should have mentioned both that and the broadcast IP address of 255.255.255.255

Though if you tried using either of those for a LAN address you wouldn't be connected to the LAN.

 

[wdmsystem]

A public IP address is an IP address that can be accessed over the Internet. Like postal address used to deliver a postal mail to your home, a public IP address is the globally unique IP address assigned to a computing device. Your public IP address can be found at What is my IP Address page. Private IP address on the other hand is used to assign computers within your private space without letting them directly expose to the Internet. For example, if you have multiple computers within your home you may want to use private IP addresses to address each computer within your home. In this scenario, your router get the public IP address, and each of the computers, tablets and smartphones connected to your router (via wired or wifi) get a private IP address from your router via DHCP protocol.

 

[alimeeabey]

Just by seeing the labels ‘private’ and ‘public’, we easily assume what should be their differences are. However, it might not be exactly what it sounds like. When talking about a public IP address, it does not essentially mean in public like Wi-Fi hotspots or an outside office, instead it means the public network with which you are connected with and that’s the internet.

It also means that a ‘public IP address’ is not your usual ‘public’ area. On the other hand, Private IP addresses are used from your office, home, or enterprise Local Area Network (LANs). These are provided by your router, or you can assign each device with an individual IP address, so long as it passes the standards of a true private IP address.

 

[Bingo600]

The private internet adresses are defined in RFC 1918
https://tools.ietf.org/html/rfc1918

And in "short" they are not routable on the internet ("read" reachable via the internet).
And every one is allowed to use them inside their own private network infrastructure.


/Bingo

 

[Mike_Tr]

Well i guess there are no public and private IPs, just LAN and WAN adresses, so you can't access LAN user from WAN directly

 

[c_mitra]

so you can't access LAN user from WAN directly

It does not appear possible but the router that connects the WAN to the LAN has some intelligence and it can keep track of the connections. That is how you can talk to the WAN from your LAN.