Cisco WRV54G - Manual (Page 9)

5 Chapter 2: Planning your Wireless Network
Why do I need a VPN?
Wireless-G VPN Broadband Router
If you use the Router to share your cable or DSL Internet connection, contact your ISP to find out if they have
assigned a static IP address to your account. If so, you will need that static IP address when configuring the
Router. You can get that information from your ISP.
Dynamic IP Addresses
A dynamic IP address is automatically assigned to a device on the network, such as PCs and print servers. These
IP addresses are called “dynamic” because they are only temporarily assigned to the PC or device. After a
certain time period, they expire and may change. If a PC logs onto the network (or the Internet) and its dynamic IP
address has expired, the DHCP server will automatically assign it a new dynamic IP address.
DHCP (Dynamic Host Configuration Protocol) Servers
PCs and other network devices using dynamic IP addressing are assigned a new IP address by a DHCP server.
The PC or network device obtaining an IP address is called the DHCP client. DHCP frees you from having to assign
IP addresses manually every time a new user is added to your network.
A DHCP server can either be a designated PC on the network or another network device, such as the Router. By
default, the Router’s DHCP Server function is enabled.
If you already have a DHCP server running on your network, you must disable one of the two DHCP servers. If you
run more than one DHCP server on your network, you will experience network errors, such as conflicting IP
addresses. To disable DHCP on the Router, see the DHCP section in “Chapter 6: The Router’s Web-based Utility.”
Why do I need a VPN?
Computer networking provides a flexibility not available when using an archaic, paper-based system. With this
flexibility, however, comes an increased risk in security. This is why firewalls were first introduced. Firewalls
help to protect data inside of a local network. But what do you do once information is sent outside of your local
network, when emails are sent to their destination, or when you have to connect to your company's network
when you are out on the road? How is your data protected?
That is when a VPN can help. VPNs are called Virtual Private Networks because they secure data moving outside
of your network as if it were still within that network.
When data is sent out across the Internet from your computer, it is always open to attacks. You may already have
a firewall, which will help protect data moving around or held within your network from being corrupted or
intercepted by entities outside of your network, but once data moves outside of your network - when you send
data to someone via email or communicate with an individual over the Internet - the firewall will no longer protect
that data.