FBVi-2U4-4T |
IP Networking
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Subject to change without notice
WWW.CYLON.COM
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NETWORK ADDRESS TRANSLATION (NAT)
Network Address Translation
is a function of a router or firewall, which maps multiple local IP addresses to
a single public IP address. This is necessary because the number of
IPv4
addresses is finite.
DOMAIN NAME SYSTEM (DNS)
When communicating on the wider Internet, it can be difficult to remember the numeric IP address for
each device with which you want to communicate. The Domain Name System (DNS) was created to allow
internet users to use a text-based Uniform Resource Locator (URL) with meaningful values such as
“www.cylon.com” to connect to a site or device without having to know the server’s IP address. The DNS
finds the URL in its distributed database and passes the corresponding numeric IP address to the
requesting device. If a device’s IP address changes, the DNS server can be updated with its new IP
address, ensuring that other networked devices can still find this device from its URL.
When setting a devices IP parameter manually, between one and three DNS IP address are usually
provided. The second and third addresses are used if the first DNS becomes unavailable.
If you do not know the address of your DNS server(s), you can use publicly available DNS server addresses
for example primary =
8.8.8.8
and secondary =
4.4.4.4
