Owner's Manual

Appendix E. Glossary | 925
NETGEAR 8800 User Manual
C
carrier VLAN In STP, carrier VLANs define the scope of the STPD, including the physical and
logical ports that belong to the STPD as well as the 802.1Q tags used to
transport EMISTP- or PVST+-encapsulated BPDUs. Only one carrier VLAN can
exist in any given STPD.
CCM In CFM, connectivity check messages are CFM frames transmitted periodically
by a MEP to ensure connectivity across the maintenance entities to which the
transmitting MEP belongs. The CCM messages contain a unique ID for the
specified domain. Because a failure to receive a CCM indicates a connectivity
fault in the network, CCMs proactively check for network connectivity.
CFM Connectivity Fault Management allows an ISP to proactively detect faults in the
network for each customer service instance individually and separately. CFM
comprises capabilities for detecting, verifying, and isolating connectivity failures
in virtual bridged LANs.
checkpointing Checkpointing is the process of copying the active state configurations from the
primary MSM to the backup MSM on modular switches.
CIDR Classless Inter-Domain Routing. CIDR is a way to allocate and specify the
Internet addresses used in interdomain routing more flexibly than with the
original system of IP address classes. This address aggregation scheme uses
supernet addresses to represent multiple IP destinations. Rather than advertise
a separate route for each destination, a router uses a supernet address to
advertise a single route representing all destinations. RIP does not support
CIDR; BGP and OSPF support CIDR.
CIST Common and Internal Spanning Tree. In an MSTP environment, the CIST is a
single spanning tree domain that connects MSTP regions. The CIST is
responsible for creating a loop-free topology by exchanging and propagating
BPDUs across MSTP regions. You can configure only one CIST on each switch.
CIST root port In an MSTP environment, the port on the CIST regional root bridge that connects
to the CIST root bridge is the CIST root port. The CIST root port is the master
port for all MSTIs in that MSTP region, and it is the only port that connects the
entire region to the CIST root bridge.
CIST regional root bridge Within an MSTP region, the bridge with the lowest path cost to the CIST root
bridge is the CIST regional root bridge If the CIST root bridge is inside an MSTP
region, that same bridge is the CIST regional root for that region because it has
the lowest path cost to the CIST root. If the CIST root bridge is outside an MSTP
region, all regions connect to the CIST root through their respective CIST
regional roots.
CIST root bridge In an MSTP environment, the bridge with the lowest bridge ID becomes the
CIST root bridge. The bridge ID includes the bridge priority and the MAC
address. The CIST root bridge can be either inside or outside an MSTP region.
The CIST root bridge is unique for all regions and non-MSTP bridges, regardless
of its location.
CLI Command line interface. You use the CLI to monitor and manage the switch.