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1-4
Catalyst 2950 Desktop Switch Software Configuration Guide
78-14982-01
Chapter 1 Overview
Features
• Address Resolution Protocol (ARP) for identifying a switch through its IP address and its
corresponding MAC address
• Cisco Discovery Protocol (CDP) versions 1 and 2 for network topology discovery and mapping
between the switch and other Cisco devices on the network
• Network Time Protocol (NTP) for providing a consistent timestamp to all switches from an external
source
• Directed unicast requests to a Trivial File Transfer Protocol (TFTP) server for obtaining software
upgrades from a TFTP server
• Default configuration storage in Flash memory to ensure that the switch can be connected to a
network and can forward traffic with minimal user intervention
• In-band management access through a CMS web-based session
• In-band management access through up to 16 simultaneous Telnet connections for multiple
command-line interface (CLI)-based sessions over the network
• In-band management access through Simple Network Management Protocol (SNMP) versions 1, 2c,
and 3 get and set requests
• Out-of-band management access through the switch console port to a directly-attached terminal or
to a remote terminal through a serial connection and a modem
Note For additional descriptions of the management interfaces, see the “Management Options”
section on page 1-7.
Redundancy
• HSRP for command-switch redundancy
• UniDirectional link detection (UDLD) on all Ethernet ports for detecting and disabling
unidirectional links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port faults
• IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free
networks. STP has these features:
–
Per-VLAN Spanning Tree (PVST) for balancing load across VLANs
–
UplinkFast, cross-stack UplinkFast, and BackboneFast for fast convergence after a
spanning-tree topology change and for achieving load balancing between redundant uplinks,
including Gigabit uplinks and cross-stack Gigabit uplinks
• IEEE 802.1S Multiple STP (MSTP) for grouping VLANs into a spanning-tree instance, and
providing for multiple forwarding paths for data traffic and load balancing (available only with
the EI)
• IEEE 802.1W Rapid STP (RSTP) for rapid convergence of the spanning tree by immediately
transitioning root and designated ports to the forwarding state (available only with the EI)
• Optional spanning-tree features available:
–
Port Fast for eliminating the forwarding delay by enabling a port to immediately transition from
the blocking state to the forwarding state
–
BPDU guard for shutting down Port Fast-enabled ports that receive BPDUs
–
BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs
–
Root guard for preventing switches outside the network core from becoming the spanning-tree
root