Because a modem is no longer needed, your computer or router will have a public IP address. If you have a router, you should consider changing the management login/password to something other than the default. This will prevent malicious users from logging onto your router. Be sure to enable firewall services on your router. If your router doesn’t have firewall services, you should consider purchasing a hardware or software firewall solution. If your PC is directly on the network (no router), you should have some sort of software firewall running. Windows XP, Vista and Windows 7 have a built-in software firewall, and there are many others that can be purchased separately.