User`s guide

186
Glossary
Router - Subnet Mask
R Router
A device that connects any number of LANs. Routers use headers and
a forwarding table to determine where packets go. They use Internet
Control Message Protocol (ICMP) to communicate with each other and
configure the best route between any two hosts. Very little filtering of data
is done through routers. Routers do not care about the type of data they
handle. Routers often have DHCP Server capability.
S server
Part of the client/server model used in distributed computing. The server
is a computer system designated to act as a main servicer of requests
from other client computer systems, such as I/O application requests,
networking requests, and so forth.
SICL
The Agilent Standard Instrument Control Library, which is software used
for I/O application programming.
SRQ
Service Request. An asynchronous request (an interrupt) from a remote
device indicating that the device requires servicing.
Subnet
A portion of a network that shares a common address component.
On TCP/IP networks, subnets are defined as all devices whose IP
addresses have the same prefix. For example, all devices with IP
addresses that start with 100.100.100. would be part of the same
subnet. Dividing a network into subnets is useful for both security and
performance reasons. IP networks are divided using a subnet mask.
Subnet Mask
A mask used to determine to what subnet an IP address belongs. An IP
address has two components: the network address and the host address.
For example, consider the IP address 150.215.017.009. Assuming this is
part of a Class B network, the first two numbers (150.215) represent the
Class B network address and the second two numbers (017.009) identify
a particular host on this network.
Subnetting enables a System Administrator to further divide the host
part of the address into two or more subnets. In this case, a part of the
host address is reserved to identify the particular subnet.