Router problem

[A7]

Hello

At our company we are using cisco router 1800 series, we have a problem and i thing it is the problem of router, the computers and IP phones are not taking ip adresess, some of computers are working but some not. What can i do with this router, is there a way to format or what to do

thanks in advance.

[nordick26]

Hi,

could you please provide more details?

Do you run DHCP on your router?

Do you have only one subnet on your LAN?

Are you using different VLANs?

Or if possible, provide your config?

Ivan