How to find my Gigaset base
Find your basestation's web interface
To find your Gigaset basestation on your local network, go to www.gigaset-config.com. This site will search your network for basestations and redirect you to the base's web interface.
You can also find the basestation's local IP address from a handset if you go to Settings -> System -> Local Network.
Finally, if the above two options don't work, log in to your router and go to the DHCP Table or ARP Cache and look for a MAC address starting 7C.
Which handsets are connected to your base
If you want to know which handset is connected to each base then give the button on the front of the base a quick press and it will page all the connected phones.