The portfile already has the correct checksums.
The portion of the error message that you did not quote above referred you to the MisbehavingServers page which explains that the problem is with your DNS servers.
Probably one of the php mirrors was removed, and because of your broken DNS servers, this turns into an error. If you let me know which mirror it was, I can remove it from the list. If you don't remember which mirror it was, try this:
sudo port clean --all php54
sudo port install php54
If the same error occurs, let me know what mirror it was. Or maybe it'll find a mirror that works and install ok.