When running the SPA9000 Setup Wizard, it must be on the same LAN as the SPA9000, SPA400, and IP phones, exactly as described and pictured in the SPA9000 Wizard User Guide or else the Wizard will not be able to automatically locate IP phones.
But what if you believe that you have followed the instructions, yet the phones are not being found?
Some issues to be aware of include:
The SPA9000 communicates with the IP phones using multicast 184.108.40.206:6061 [beware of switch-to-switch connections]
Verify that your DHCP server is not providing DHCP OPTION 66. This is an IP address to a TFTP server. If phones receive a dynamic IP address from a DHCP server and included in the DHCP OFFER from the DHCP server is option 66, the phones will not attempt to communicate with the SPA9000 and will thus not be found by the SPA9000 Setup Wizard
Verify that you are not running VLANs on the network. If you are, verify that the SPA9000 Setup Wizard on the data network, has access to the IP phones on the Voice network, else the SPA9000 Setup Wizard will not find any IP phones.
The SPA9000 boots very fast, only taking several seconds, faster than Spanning Tree can converge switch ports. Enable Port-Fast for the SPA9000, SPA400, and all IP phones because they are edge ports and do not pose a risk of STP loops. If you cannot enable Port-Fast, disable STP or else the SPA9000, SPA400, and IP phones will have difficulty communicating with each other after a reboot. [An easy test is to power-cycle the SPA9000. Carefully watch to ensure that all IP phones reboot within about 5 seconds of the SPA9000 booting up. If the phones do not reboot, that's an indication that multicast is being impeded in some way]