Version 4.0| Version 4.0 |
User's Guide |
4. Configuring NetProxy Services
4.9. DHCP Service
NetProxy includes a Dynamic Host Configuration Protocol (DHCP) server, which can automatically configure the TCP/IP settings for the machines on your network.
The DHCP server assigns IP addresses within the range you specify to the other computers on your network. Along with each address assignment, NetProxy also specifies the following TCP/IP settings: -
Subnet mask. This should usually be 255.255.255.0, but it may different if you have a previously assigned set of IP addresses for your network, or if you have a network consisting of more that 254 computers.
Default gateway. This should usually be left blank, as you do not need a default gateway to use NetProxy from a single IP network. For more complex setups such as Intranets split across several subnets, you may need to specify the IP address of a router to assign as the default gateway for the computers on your network.
Primary and Secondary DNS servers. In a typical setup, the primary DNS server should be the IP address of the NetProxy PC (assuming you have enabled the “DNS forwarding” option in the SOCKS server settings). More complex networks may have one or more DNS servers available, the IP addresses of up to two DNS servers may be specified in the primary and secondary DNS server fields.
The DHCP Server
configuration dialog is shown below. For specific help on each of the settings,
click the Windows 'context help' icon at the top of the dialog box in NetProxy,
then select the item you wish to learn more about.
Bind To
Interface
Allows you to select a specific IP interface that NetProxy should bind the
service to. Any connection attempts not received on this IP address will be
blocked by the operating system before they even reach NetProxy's
firewall.
For example, if the IP address assigned to your local network card is selected, any connections arriving via your external IP interface (the one belonging to your dialup or ADSL connection) will be rejected by Windows.
First IP
Address
Specifies the starting IP address that NetProxy uses when assigning address to
network client machines. If you alter this setting, you are advised to reset
the DHCP allocation table.
Last IP
Address
Specifies the final IP address in the pool of addresses that NetProxy assigns
to network client machines. If you alter this setting, you are advised to reset
the DHCP allocation table.
Subnet
Mask
Specifies the IP subnet mask that is assigned to network clients using the DHCP
protocol. For a typical NetProxy installation, this will be
"255.255.255.0" but it may be altered for use with more complex
setups.
Default Gateway
Specifies the IP address of a router which will act as the default
gateway for the client machine. In a typical setup, this setting should be
empty, however it may be useful for more complex setups such as Intranets that
are split across several subnets.
Primary DNS server
Specifies the IP address of the primary DNS server that the machines
on your network will use when attempting to resolve Internet host names to IP
addresses. In a typical setup, this should point to the IP address of the
NetProxy PC.
Secondary DNS
server
Specifies the IP address of a secondary DNS server for the machines on
your network. In a typical setup, this setting should be empty.
Reset Allocation
Table
Resets the DHCP allocation table. This table records which IP addresses have
been leased to which machines. If you make any major changes to the DHCP
settings, it is recommended that you reset the DHCP allocation table in order
to ensure that the changes are propagated around your network.
To make use of the DHCP server, set your network client computers
to “obtain an address from a DHCP server”.
NetProxy allocates IP addresses with an infinite lease time.
NetProxy’s DHCP server correctly handles DHCP_RELEASE
messages, which are sent when a client machine wishes to relinquish its
assigned IP address. NetProxy adds released IP addresses back into the pool of
available addresses.