User`s guide

187
Glossary
Switch - symbolic name
For example, the full address for 150.215.017.009 is
10010110.11010111.00010001.00001001. The Class B network part is
10010110.11010111 and the host address is 00010001.00001001. If this
network is divided into 14 subnets, the first four bits of the host address
(0001) are reserved for identifying the subnet.
The subnet mask is the network address plus the bits reserved for
identifying the subnetwork. (By convention, the bits for the network
address are all set to 1, though it would also work if the bits were set
exactly as in the network address.) In this case, the subnet mask is
11111111.11111111.11110000.00000000.
It is called a mask because it can be used to identify the subnet to which
an IP address belongs by performing a bitwise AND operation on the
mask and the IP address. The result is the subnetwork address:
Subnet Mask 255.255.240.000
11111111.11111111.11110000.00000000
IP Address 150.215.017.009
10010110.11010111.00010001.00001001
Subnet Address 150.215.016.000
10010110.11010111.00010000.00000000
Switch
A device that filters and forwards packets between LAN segments.
Switches operate at the data link layer (layer 2) and sometimes the
network layer (layer 3) of the OSI Reference Model and therefore support
any packet protocol. LANs that use switches to join segments are called
switched LANs or, in the case of Ethernet networks, switched Ethernet
LANs. A hub connects all the devices on its "ports" together.
A switch is a bit smarter, as it understands when two devices (out of four,
five, eight, sixteen, or even more) want to talk to each other and gives
them a switched connection.
symbolic name
A name corresponding to a single interface. This name uniquely
identifies the interface on a controller or gateway. If there is more than
one interface on the controller or gateway, each interface must have a
unique symbolic name.