Compatible Systems 5.4 - Manual (Page 286)

280 Appendices
Chart 4: Broadcast Address Examples
The first three entries are traditional Class A, B and C network addresses and
use traditional masks. The last two are less traditional, “real world” examples.
Note in line 4 the change in the third octet between network address and
broadcast address. Line 5 shows what happens when a Class C network has
been subnetted.
Assigning an IP address
Use the network portion you were given by your administrator or ISP. Assign
the router interface a unique (i.e. unused) host portion. For example, if your
ISP tells you your network portion is 198.41.9, you could assign an interface
to 198.41.9.1. If you have a router with more than one interface, the network
(+ subnet) portions of each port’s IP address must be different.
Assigning a Subnet Mask
If you are using traditional Class A, B or C networks, CompatiView will auto-
matically calculate the value for you. If you wish to compute it yourself, use
the values in Chart 2.
If you are subnetting, use Chart 3 as a guide for Class C, or follow the same
scheme for Class A or B. Note that the IP address for a subnetted interface
(including the router interface on that subnet) must be in the correct subnet
range, as shown in Chart 3.
Assigning a Broadcast Address
CompatiView will automatically compute the broadcast address for you. If
you wish to compute it yourself, use the examples in Chart 4 above as a guide.
You can then use CompatiView to check your results.
C LASS N ETWORK S UBNET M ASK B ROADCAST
A 45.0.0.0 255.0.0.0 45.255.255.255
B 128.138.0.0 255.255.0.0 128.138.255.255
C 198.41.9.0 255.255.255.0 198.41.9.255
A* 45.21.16.0 255.255.252.0 45.21.19.255
C* 198.41.9.64 255.255.255.224 198.41.9.95