I have a SonicWall firewall. A physical device, unlike the Windows software firewall (as I understand it). The SonicWall has about 6 RJ45 ports to plug stuff into. The credit card people said I have to have my terminal behind a firewall. I asked an IT person and they said go ahead, plug it in and we'll deal with it if it doesn't work. It works. The credit card company did some kind of 24 hr scan and it passed their scrutiny. Does a firewall automatically confer protection to anything plugged into it without 'setup' or software modification on either the firewall or the protected device?