[SOLVED] IP addresses and DHCP

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BoodaGazelle

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This is a pretty basic question. I know that IP addresses in the range of 192.168.x.x are for personal use
and are assigned by DHCP (right?).

My ISP of course has their own range of "real" IP addresses, but unless I ask for or get a static one of those,
I get one of the 192.168 ones.

If I have 3 devices in my house, isn't it true that of these three (192.168.0.1, 192.168.0.2 and 192.168.0.3),
each device could get any one of these depending upon the order they are powered on?

Therefore, how can a bulletin board recognize me if I try to log in after I was booted off? How would they
distinguish my 192.168.0.1 from the many others at my ISP?

Does the ISP really send one of their IP addresses to the BB? If so, how is that different from me having
a static IP address?

Thanks,

Mitch
 
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the 192.168.x.x address is only internal to your local network. it's how the router knows which device to send which traffic to. once the traffic leaves your local network (passes through the edge router), it is using your public ip which is given to you by your isp.

you can think of it kind of like and apartment building. 101 main street, anycity usa would be your public address and is enough to get stuff to the building (ie you're local network). but nce it gets there, the private address of apt 1, 2, 3 or a, b, c and so on is how that mail gets to each unit.

dhcp only assigned the local private address, though you can assign each device its own static address that won't change.

your public isp address also changes and is...

Math Geek

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the 192.168.x.x address is only internal to your local network. it's how the router knows which device to send which traffic to. once the traffic leaves your local network (passes through the edge router), it is using your public ip which is given to you by your isp.

you can think of it kind of like and apartment building. 101 main street, anycity usa would be your public address and is enough to get stuff to the building (ie you're local network). but nce it gets there, the private address of apt 1, 2, 3 or a, b, c and so on is how that mail gets to each unit.

dhcp only assigned the local private address, though you can assign each device its own static address that won't change.

your public isp address also changes and is assigned by the isp's own dhcp server which is why it changes regularly as well. you can usually pay extra to get a static public address from your isp if you need it but it is not cheap usually.
 
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BoodaGazelle

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This is really about why my HP 1217nfw Wifi printer works sometimes and not others. I really do not want to have to assign IP addresses from my router for the printer, but I may have to.
 

Math Geek

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if you are not trying to print from the web, a random dhcp assigned ip should be good enough since only local ip's will talk to it.

but for internet printing, a static ip is usually needed to get it working. though the handful of times i have tried to get that working, it was maybe 50% successful.
 
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This is really about why my HP 1217nfw Wifi printer works sometimes and not others. I really do not want to have to assign IP addresses from my router for the printer, but I may have to.

I literally set a static IP address for all my printers because I never want it to change. You can accomplish this via a DHCP reservation or set it static outside the IP address range of the DHCP of your router.

Option 1: Make a DHCP reserveration on your router. The router will reserve and ip address and only assign it to the MAC id of your printer.

Option 2: On your printer, you can set a static IP address. This address needs to be outside the DHCP range of your router. If your router has a range of 100 clients and the range starts from 192.168.1.2 and goes to 192.168.1.102. Then you need to set the printer to take an IP address of 192.168.1.103 or higher up to 192.168.1.255.
 
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