Glossary
GL-9
Cisco IOS XR Getting Started Guide
OL-10957-02
PPP Point-to-Point Protocol. Successor to SLIP that provides router-to-router and host-to-network
connections over synchronous and asynchronous circuits. Whereas SLIP was designed to work with IP,
PPP was designed to work with several network layer protocols, such as IP, IPX, and ARA. PPP also
has built-in security mechanisms, such as CHAP and PAP. PPP relies on two protocols: LCP and NCP.
primary RP The first route processor configured for DSC or logical router operation. If a second RP is configured
as a redundant RP, it becomes the secondary RP.
Q
QoS quality of service. A set of parameters that describes a flow of data, such as guaranteed bandwidth,
delay, and delivery guarantee.
R
RCP remote copy protocol. A protocol that allows users to copy files to and from a file system residing on
a remote host or server on the network. The RCP protocol uses TCP to ensure the reliable delivery of
data.
RIB Routing Information Base. This is the set of all available routes from which to choose the FIB. The RIB
essentially contains all routes available for selection. Essentially, it is the sum of all routes learned by
dynamic routing protocols, all directly attached networks (that is. networks to which a given router has
interfaces connected), and any additional configured routes, such as static routes.
RIP Routing Information Protocol. A simple routing protocol that is par t of the TCP/IP protocol suite and
the most common IGP in the Internet. RIP determines a route based on th e smallest hop count between
source and destination. It is a distance vector protocol t hat broadcasts routing information to
neighboring routers. It is known to use excessive bandwidth. See also hop count a nd IGP.
ROM Monitor ROM Monitor is a bootstrap program that initializes the hardware and boots the system when a router
is powered on or reset. ROM Monitor mode is also known as “ROMMON,” which reflects the CLI
prompts for the mode.
rommon B1> (Cisco CRS-1 routers)
or
rommon1> (Cisco XR 12000 Series Routers)
ROMMON See ROM Monitor.
router Network layer device that uses one or more routing metrics to determine the opti mal path along which
network traffic should be forwarded. Routers forward packets from one network to another based on
network layer information.
routing Process of finding a path to a destination host. Routing is very complex in large net works because of
the many potential intermediate destinations a packet might traverse before reaching its destination
host.