"Another device on the network is using your computer's IP address" - error

Hello,

I recently purchased 2 brand new MACs... One MacBook Air, and the other an iMac.

When walking through the initial setup, I set up both machines with identical usernames, passwords, etc (I did this so that I can set up both machines so they will have identical content - one at home, the for traveling. I plan on setting up rsync to synchronize data).

Now it appears that setting both machines identically has caused a problem on my wireless network. I receive an error:

"Another device on the network is using your computer's IP address"

When I attempt to "Renew DHCP Lease", the IPv4 address is 169.x.x.x

I believe I'm getting this error because I have setup the 2 - Macs with the same name, password, etc.

Does anyone have any ideas of what (and how) to change assuming my assumptions are correct (that the router runnnig DDWRT thinks there are 2 machines with the same info)?

Thanks in advance

Are either or perhaps both of the Macs set to use manual DHCP addresses? If so that may be the issue. You should be able to change that setting without messing up other things you want to keep the same.

Nope.. both should be set to DHCP as I never manually configured them for a static IP.

Looks like I figured it out.. my router was only setup to hand out 10 IP addresses (even though I have less than 10 devices), and was thinking they were all in use for some reason.

At any rate, increased the number of IPs in my router to 30, and it seems to have fixed the issue.

Thanks everyone!

Thanks for posting the fix. I'll have to file that away for future referenced. I did not think if that because my network setup already has something similar in place. I told my primary router to use DHCP but to start assigning addresses where the last pair of digits is something like 20. This allows most of the network to get assigned a number automatically but a few devices can be assigned fixed numbers manually.