MacBook Pro ip address same as airport

MacBook Pro Yosemite 10.10.2

Airport Wireless (I don't have specs for this connection point)

I frequently have Girl Scout meetings at a location (friend's place of business) that has wifi. The router is an airport and the provider is Comcast.

It seems that all other devices do not have a problem connecting to this wifi, except for my macbook pro. I have multiple ipads, pc and mac laptops, iphones, all connect.

When I try to connect with my MacBook Pro I get an error telling me that I cannot connect because I'm trying to use an ip address that is already on the system.

After further investigation I discovered that the computer is defaulting to the ip address of the airport.

I tried entering the ip address in manually. To be sure I had an ip address that had worked I used the ip address an ipad was using and shut of the ipad. I could get a connection to the network. The green light and a message telling me I'm connected to the network. But I could not get an internet connection.

This is so frustrating. Why is it so difficult? I have looked all over the place for an explanation. Thinking there is some stupid setting that I'm missing... hope it's a simple fix! I'm worried this could happen at another location when I need it even more!