Glossary 397
Subnet
Sub-network. Subnets are portions of a network that share a common address component. On TCP/IP networks,
devices that share a prefix are part of the same subnet. For example, all devices with a prefix of 157.100.100.100
are part of the same subnet.
Subnet Mask
Used to mask all or part of an IP address used in a subnet address.
Switch
Filters and forwards packets between LAN segments. Switches support any packet protocol type.
T
TCP/IP
Transmissions Control Protocol
. Enables two hosts to communicate and exchange data streams. TCP guarantees
packet delivery, and guarantees packets are transmitted and received in the order their sent.
Telnet
Terminal Emulation Protocol.
Enables system users to log in and use resources on remote networks.
TFTP
Trivial File Transfer Protocol
. Uses User Data Protocol (UDP) without security features to transfer files.
Trap
A message sent by the SNMP that indicates that system event has occurred.
Trunking
Link Aggregation.
Optimizes port usage by linking a group of ports together to form a single trunk (aggregated
groups).
U
UDP
User Data Protocol.
Transmits packets but does not guarantee their delivery.
Unicast
A form of routing that transmits one packet to one user.