how IP address is assigned?

[Matthew Louden]

I want to know how a computer's IP address is assigned?? Somebody told me if
the computer is on LAN, there is one IP. But there is another IP when people
outside the network sees that.

I am curious if the IP address is assigned by router, by firewall, or by ISP
provider? How come everytime I type ipconfig, the IP is unchanged?? If it is
dynamic IP, it should change all the time.

Please help!!

 

[John Wunderlich]

I want to know how a computer's IP address is assigned?? Somebody
told me if the computer is on LAN, there is one IP. But there is
another IP when people outside the network sees that.

I am curious if the IP address is assigned by router, by firewall,
or by ISP provider? How come everytime I type ipconfig, the IP is
unchanged?? If it is dynamic IP, it should change all the time.

Your internet IP address is assigned by your ISP's DHCP server. If you
have a router, then the router gives itself that address otherwise your
computer takes that address. This is the address others on the
internet must use to contact you.

If you have a router, then the router acts as a DHCP server and assigns
connected equipment Local Non-routable addresses (usually in the
192.168.x.x or 10.x.x.x range). Outside internet connections can only
get through if data was first requested by a Local computer (so the
router knows which computer gets the answer) or the router has been
configured for port forwarding or a DMZ computer.

DHCP is dynamic but maintains a strong preference to assign the same IP
address that was assigned before. Normally, only if that IP address is
not available will it be changed to another.

HTH,
John