Troubleshooting network peripherals
Normally a single wireless access point has enough range to cover an entire house. If you add a Time Capsule, you should connect it to your router using an Ethernet cable and use AirPort Utility to turn off Wi-Fi on the Time Capsule. This keeps your home network as simple as possible. If you have a very large house, or an old one with thick stone walls and lots of nails in the floorboards, you may need extra Wi-Fi access points to reach every room. If you do this, make sure that you turn off the DHCP server on every device except for your router. DHCP is the service that assigns local IP addresses to each computer on your network, and you don’t want two Wi-Fi access points fighting with each other.
Likewise, only enable Network Address Translation (NAT) on your broadband router. If two devices are using NAT, your network will effectively be split into two subnetworks, and some services such as FaceTime and online games might find it hard to reach the internet across this split.
Some older networked drives or printers might have been set up with a static IP address. They work fine until you change internet provider and get a new broadband router. Then suddenly you can’t connect to them. This is because the new router has a different default range of IP addresses that are clashing with the static address on your old device. If you can, change the device to use DHCP so it always receives a valid address from the router. If it doesn’t allow this, you’ll have to pick a new static IP address that lies outside of the range of IP addresses that the router can supply via DHCP. So, if the router configuration page says the DHCP server has an ‘End IP address’ of 192.168.1.254, change this to 192.168.1.250 and then assign 192.168.1.251 to your printer or networked drive.