Cisco OL-4015-08 User Manual page 662

Glossary
NAD
NAS
NAT
Network Address
Translation
NetFlow
network
network bits
network module
Cisco Router and Security Device Manager Version 2.2 User's Guide
GL-20
Network Access Device. In a NAC implementation, the device that receives a
host's request to log on to the network. A NAD, usually a router, works with
posture agent software running on the host, virus protection software, and ACS
and posture/remediation servers on the network to control access to the network
in order to prevent infection by computer viruses.
Network Access Server. Platform that interfaces between the Internet and the
public switched telephone network (PSTN).
Gateway that connects asynchronous devices to a LAN or WAN through network
and terminal emulation software. Performs both synchronous and asynchronous
routing of supported protocols.
Network Address Translation. Mechanism for reducing the need for globally
unique IP addresses. NAT allows an organization with addresses that are not
globally unique to connect to the Internet by translating those addresses into
globally routable address space.
A feature of some routers that allows them to categorize incoming packets into
flows. Because packets in a flow often can be treated in the same way, this
classification can be used to bypass some of the work of the router and accelerate
its switching operation.
A network is a group of computing devices which share part of an IP address
space and not a single host. A network consists of multiple "nodes" or devices
with IP address, any of which may be referred to as hosts. See also Internet,
Intranet, IP, LAN.
In a subnet mask, the number of bits set to binary 1. A subnet mask of
255.255.255.0 has 24 network bits, because 24 bits in the mask are set to 1. A
subnet mask of 255.255.248 has 17 network bits.
A network interface card that is installed in the router chassis to add
functionality to the router. Examples are Ethernet network modules, and
network modules.
IDS
OL-4015-08