how IP address is assigned?

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!!

"Matthew Louden" <(E-Mail Removed)> wrote in
news:#(E-Mail Removed):

> 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

Hello There Matt.

I'm curious to know what IP address it is that you're
referring about when you type IP Config? If you're doing
it from within a computer in your LAN, then it should be
in the IP ranges that John Wunderlich stated (the other
person that responded to your question). As john stated,
it should be in the 192.168.XXX.XXX or the 10.XXX.XXX.XXX
range. But depending on how you have your network set up,
you could have a computer getting an IP directly from you
ISP, and thus making the IP public, and still have a
router connected to the LAN, that also spits out Private
IP Addresses to other client nodes. The reason why I touch
this point is because I have noticed that even though the
IP issued by your ISP server is done dynamically, it can
still remain the same. So, if you were to type IP config
on the computer with a the public IP address say today,
and you noticed an IP address of (for example) 12.2.175.35
today, it is possible that if you type ipconfig on your
computer 2 weeks from now that you will still have that
same IP address. I've had some friends think that they are
on static IP's because of that reason.

There's my two cents worth.

Thanks.

>-----Original Message-----
>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!!
>
>
>.
>