Adding static ip device to DHCP LAN

[megmcadam]

I have a DHCP LAN using a comcast gateway and I need to add a device that requires a static ip address. How do I add it to my DHCP network?

 

[mbreslin1954]

Find out the range of DHCP addresses being handed out by your router, then set the device that needs it a static IP address outside of that range. So for instance if your router is handing out addresses from 192.168.1.100 through 192.168.1.200, then you give your device a static IP address of 192.168.1.10. Or 192.168.1.11. Or anything less than 192.168.1.100.

But you can't do this safely unless you know the range of addresses being handed out by your router (that's what a "gateway" is in reality, a router).

 

[megmcadam]

Find out the range of DHCP addresses being handed out by your router, then set the device that needs it a static IP address outside of that range. So for instance if your router is handing out addresses from 192.168.1.100 through 192.168.1.200, then you give your device a static IP address of 192.168.1.10. Or 192.168.1.11. Or anything less than 192.168.1.100.

But you can't do this safely unless you know the range of addresses being handed out by your router (that's what a "gateway" is in reality, a router).

Makes sense. The ip address was preset by the factory and it is well outside the range that my router is using. It's still not being recognized. The documentation for the device tells me to add the static ip address in my TCP/IP settings on my computer but doesn't that mean the ip gets assigned to my computer, not the device (it's a restaurant scale)?

 

[kanewolf]

The first three octets of the static IP address MUST be the same as your DHCP range. If your DHCP range is 192.168.1.100 to 192.168.1.199 then you must pick an address with the same first three numbers (octets) but a 4th number outside the range of 100 to 199 (and not 1, because that is your router). Starting at 250 and working DOWN is usually a safe strategy.

 

[Ijack]

Is this a device that is to be accessed only from your computer, from several devices on your network, from the outside worls, or what?

You say that it has already been assigned a fixed IP address; what is that address, and what is the range of addresses that your DHCP server supplies? It may be that you need to add a second IP address to your computer just to communicate with this device. A few more details about the setup and how the devices are connected would help.

 

[megmcadam]

The first three octets of the static IP address MUST be the same as your DHCP range. If your DHCP range is 192.168.1.100 to 192.168.1.199 then you must pick an address with the same first three numbers (octets) but a 4th number outside the range of 100 to 199 (and not 1, because that is your router). Starting at 250 and working DOWN is usually a safe strategy.

THANK YOU BOTH!!! Between that information and finally getting a tech support person to tell me the steps to modify the static ip address on the scale (the documentation was missing a key step!!!), I can finally see the scale on my network!!!!