Using MacBook Pro running OS 10.11.5 and just installed an Airport Extreme Router. Primary network operating as advertised, but when I tied to join the guest network to check it out, Network Preferences showed "WiFi has self-assigned IP address ---.---.---.--- and will not be able to connect to the internet." I found online references for how to fix what was described as a common WiFi connection issue — self-assigned IP on a MacBook — by selecting "Use DHCP with a manual address." I did that and entered the IP address for the primary network, which allowed me to join the guest network, but it isn't connected to the internet. I've been unsuccessfully searching for a solution and would appreciate any suggestions. Thanks in advance for any help you can offer. Update: I just found Mork's thread on the same topic, and while it offers a number of suggestions, it doesn't appear to have found a solution. Apple Support information about guest networks says: "The DHCP and NAT option in AirPort Utility application > Network tab > Router Mode (default mode) must be selected on your primary base station, and Off (Bridge Mode) should be selected for any other AirPort base stations on the network." I've tried this twice, and both times it has completely terminated my connection to the router and the internet, and it puts Airport Utility in an unusable mode for doing anything else.