Error message on start up

[Chris& Karen Morgan]

Can someone help me by explaining how I can overcome the following error message:-

Could not look up internet address for x1-6-00-11-2f-35-38-bf.
This will prevent GNOME from operating correctly.
It may be possible to correct the problem by adding
x1-6-00-11-2f-35-38-bf to the file /etc/hosts.

It's my first day using Fedora and i'm totally new to Linux.

Thanks,
Chris