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DSL-504 ADSL Router User’s Guide

End IP Address

This is the last address of the contiguous IP address range to be used by the

Router for DHCP function.

Netmask

This mask informs the client, how the destination IP address is to be divided into

network, subnet, and host parts. The netmask has ones in the bit positions in the

32-bit address which are to be used for the network and subnet parts, and zeros

for the host part.

Default Gateway

This specifies the Gateway IP Address that will be assigned to and used by the

DHCP clients.

Leased Time

This specifies the amount of time (in seconds) a client can lease an IP address,

from the dynamically allocated IP pool. A value of 4294967295 means the lease is

permanent.

DNS Server IP

Domain Name Service (DNS) servers are used on the Internet to match the

Uniform Resource Locator (URL) for a website to its Internet IP address. For

example, the URL: www.cnn.com, is a pseudonym for the IP address:

207.25.71.25. DNS entries allow users to access resources using URLs instead of

IP addresses.

You may enter any Internet DNS server IP address available through the WAN

connection. This address should be provided by your network service provider.

(Note that without a DNS server IP, internet sites will only be available using IP

addresses and will not be available using URLs.)

State

This toggles Disable and Enable for DHCP function.

NAT Configuration

Network Address Translation (NAT) is a routing protocol that allows your

network to become a private network that is isolated from, yet connected to the

Internet. It does this by changing the IP address of packets from a global IP

address usable on the Internet to a local IP address usable on your private

network (but not on the Internet) and vice-versa. The Router allows up to 128

host IP addresses.

NAT has two major benefits. First, NAT allows many users to access the Internet

using a single global IP address. This can greatly reduce the costs associated with

Internet access and also helps alleviate the current shortage of Internet IP

addresses. Secondly, the NAT process creates an added degree of security by

hiding your private network behind one IP address. The NAT function will

normally only allow incoming packets that are generated in response to a request

from a host within the LAN.