Compatible Systems 5.4 - Manual (Page 39)

Chapter 2 - IP Routing & Bridging 33
• If checked, then you must set an IP Address, Subnet Mask, and Broad-
cast Address (as described below) for this VPN port. The default is
unchecked.
IP Address
If you wish to assign an IP address, it must be unique. Part of this address
identifies the network segment the router interface is connected to, and the
remainder uniquely identifies the router interface itself.
This address should be entered as four decimal numbers separated by periods
-- for example, 198.238.9.5
v Note: The single most common problem encountered in IP networking is
the use of a duplicate IP address. You must carefully track the network
numbers you have assigned to various devices in order to avoid hard-to-diag-
nose problems.
Network IP Subnet Mask
Most IP networks use “subnetting” in order to subdivide a large network into
smaller logical sub-networks. The subnet mask value is used to tell the device
what part of the IP address identifies the network segment (the “network”
portion), and what part identifies individual interfaces (the “host” portion).
There are three generally used “classes” of subnetted IP networks: A, B and
C. Each class uses a different amount of the IP address for the network and
host portions. These classes may also be further divided by correctly setting
the subnet mask.
If you do not enter a number in the Subnet Mask field, CompatiView will
derive a default value from the IP Address number you entered just above.
This default assumes you want a single subnet for all of the available host
addresses. You must manually set the field if you want to further divide the
address range.
To have CompatiView calculate a default mask, make sure that the Subnet
Mask field is empty, (re)position the cursor in the IP Address field, then just
tab through the Subnet Mask field.
Network IP Broadcast Address
The standard broadcast address is all 255’s (hexadecimal FFs) in the host
portion of the address. A few networks use all zeroes in this field. If you are
unsure which type your network uses, check with your network administrator.
To have CompatiView calculate a default broadcast address, make sure that
the Broadcast Address field is empty, (re)position the cursor in the Subnet
Mask field, then just tab through the Broadcast Address field.