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Cisco ASR 9000 Series Aggregation Services Router Getting Started Guide
OL-28417-02
Chapter
SPF
shortest path first. Routing algorithm that iterates on length of path to determine a shortest-path
spanning tree. Commonly used in link-state routing algorithms. Sometimes called Dijkstra's algorithm.
SSH
Secure Shell. A protocol that provides a secure remote connection to a router through a Transmission
Control Protocol (TCP) application.
SSL
secure socket layer. A secure socket between two entities with authentication.
standby
Denotes an inactive card or process that waits to become active; standby cards or processes are also
sometimes denoted as backup.
startup
configuration
The router configuration designated to be applied on the next router startup.
subinterface
Virtual interfaces created on a hardware interface. These software-defined interfaces allow for
segregation of traffic into separate logical channels on a single hardware interface and better utilization
of the available bandwidth on the physical interface.
switchover
A switch between the active and standby cards. The switchover can be initiated by command, or it can
occur automatically when the active card fails.
system reload
Reload of a router node.
system restart
Soft reset of a router node. This involves restarting all processes running on that node.
T
TAC
Cisco Technical Assistance Center.
TACACS
Terminal Access Controller Access Control System. Authentication protocol, developed by the DDN
community, that provides remote access authentication and related services, such as event logging.
User passwords are administered in a central database rather than in individual routers, providing an
easily scalable network security solution.
tar
A tar file is a file produced by the UNIX tar program, which packages multiple files in a single file for
distribution as a single unit. Each tar file has a tar filename extension.
target configuration
A “two-stage” configuration of the Cisco IOS XR software running configuration. This allows users to
make changes to the running configuration and accept these changes by entering the commit command.
task ID
An identifier that determines user access to a given command or series of commands. A user must be
a member of a group with the appropriate task IDs assigned to it to execute the related commands.
Tbps
terabits per second. The amount of data that can be sent in a fixed amount of time. 1 terabit = 2
40
bits,
or 1,099,511,627,776 bits.
TCP
Transmission Control Protocol. Connection-oriented transport layer protocol that provides reliable
full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
Telnet
Standard terminal emulation protocol in the TCP/IP protocol stack. Telnet is used for remote terminal
connection, enabling users to log in to remote systems and use resources as if they were connected to
a local system. Telnet is defined in RFC 854.