Cisco 2950 User Manual

Cisco Catalyst 2950 Series

Fast Ethernet Desktop Switches

DATA SHEET

Overview

The Cisco Catalyst® 2950 Series of fixed
configuration, wire-speed Fast Ethernet desktop
switches delivers premium performance and
functionality for local-area networks (LANs). These
standalone, 10/100 autosensing switches provide
enhanced quality of service (QoS) and multicast
management features—managed with the
easy-to-use, Web-based Cisco Cluster Management

®

Suite (CMS) and integrated Cisco IOS
The Catalyst 2950 Gigabit-over-copper version with
10/100/1000BaseT uplinks offers medium-sized
businesses andenterprise branchoffices with an ideal
solution to migrate from Fast Ethernet to a
higher-performance Gigabit Ethernet backbone using
existing Category 5 copper cabling.

The Catalyst 2950 Series consists of the Catalyst
2950T-24, 2950-24, 2950-12, and 2950C-24 switches.
The Catalyst 2950-24 Switch provides 24 10/100
ports; the 2950-12 has 12 10/100 ports; the 2950T-24
has 24 10/100 ports with 2 fixed 10/100/1000BaseT
uplink ports; and the 2950C-24 has 24 10/100 ports
with2 fixed 100BaseFXuplinkports. Each switchhas
a one rack-unit (RU) form factor, making them very
flexible to deploy, either on a desktop ormounted ina
wiring closet (Figure 1).

Software.

Figure 1 Catalyst 2950 Series 10/100/1000 Switches

Wire-Speed Performance in Connecting End-Stations to the LAN

With a switching fabric of 8.8 Gigabits per second
(Gbps) and a maximum forwarding bandwidth of 4.4
Gbps, the Catalyst 2950 switches deliver wire-speed
performance on all ports in connecting end-stations
and users to the company LAN.

Catalyst 2950 switchessupport performance boosting

®

features such as Fast EtherChannel
EtherChannel technology, offering up to 4-Gbps of
high-performance bandwidth between Catalyst
switches, routers, and servers.

and Gigabit

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Migrate to Gigabit Speeds in the LAN

Midmarket customers who have e xisting copper (Category 5,
UTP) wiring infrastructure in their buildings no w have a truly
compellingsolution tomigrate to Gigabitspeeds in theirLANs.
The Catalyst 2950T-24 deliv ers tw o fixed 10/100/1000BaseT
(Gigabit-Ethernet-over-copper) uplink ports in addition to
24 10/100 ports for desktop connectivity. For a fractional
increment in price per port, midsized businesses can now
upgrade their LANs to higher-performance Gigabit Ethernet.

Multicast Management via IGMP Snooping

The Internet Group Management Protocol (IGMP) Snooping
feature allows the switch to “listen in” on the IGMP
conversation between hosts and routers. When a switch hears
an IGMPjoin request froma host for a givenmulticast group,
the switch adds the host’s port number to the Group
Destination Address (GDA) list for that group. And,when the
switch hears an IGMP leaverequest, it removesthe host’sport
from the Content Addressable Memory (CAM) table entry.

In conjunction with the new Catalyst 3550-12T multilayer
Gigabit Ethernet switch,the Catalyst 2950T-24switch provides
an integrated Gigabit-Ethernet-over-copper solution for
midmarket customers who have outgrown their Fast Ethernet
backbones.

Sophisticated Quality of Service

The Catalyst 2950 Series delivers sophisticated LAN-edge
QoS, unmatched inits category ofproducts in theindustry.All
Catalyst 2950switches support two modes of reclassification.
One mode—based on the IEEE 802.1p standard—honors the
class-of-service (CoS) value at the ingress point and assigns
the packet to the appropriate queue. In the second mode,
packets can be reclassified based on a default CoS value
assigned to the ingress port by the network administrator. In
the case of frames that arrive without a CoS value (such as
untagged frames), Catalyst 2950 switches support
classification based on a default CoS value per port assigned
by the network administrator.

Once theframes havebeen classified or reclassified usingone
of the abovemodes,they are assignedto the appropriatequeue
at the egress. Catalyst 2950 switches support four egress
queues, which allow the network administrator to be more
discriminating and granular in assigning priorities for the
various applications on the LAN traffic. Strict Priority
Scheduling configuration ensures time-sensitive applications
such as voice, always follow an expedited path through the
switch fabric. Weighted Round Robin (WRR) scheduling,
another significant enhancement, ensures that lower-priority
traffic receives attention without comprising the priority
settings administered by a network manager.

By supporting IGMP Snooping in hardware andconfiguration
of IGMP Snooping via the Cisco Cluster Management Suite,
Catalyst 2950 switches deliver outstanding performance and
ease of use in administering and managing multicast
applications on the LAN.

Cisco Cluster Management Suite

The Cisco Cluster Management Suite (CMS) is Web-based
software that is embedded in Catalyst 2950, 3550-12T, 3500
XL, 2900 XL, and 1900 switches. Through Cisco Switch
Clustering technology, users access CMS with any standard
Web browser to manage up to 16 interconnected Catalyst
2950, 3550-12T, 3500 XL, 2900 XL, and 1900 switches at
once—regardless of their geographic proximity—using a
single-IP address. CMS provides an integrated management
interface for all Cisco IOS functionality, firmware
management, and offers administrators a powerful graphical
user interface (GUI) tool to easily monitor and manage their
LANs.

CMS supports a broad range of standards-based connectivity
options and configurations to deliver levels of performance
that are scalable to meet customer requirements. Switch
Cluster connectivity options for Catalyst 2950 switches
include Ethernet, Fast Ethernet, Fast EtherChannel, Gigabit
Ethernet (1000BaseT), and Gigabit EtherChannel
connectivity. Because the technology is not limited by
proprietary stacking modules or stacking cables, CMS
expands the traditional cluster domain beyond a single wiring
closet and lets users mix and match interconnections to meet
specific management, performance, and cost requirements.

These features allow network administrators to prioritize
mission-critical, time-sensitive traffic, such as ERP (Oracle,
SAP, and so on), voice (IP telephony traffic), and CAD/CAM
over less time-sensitive applications such as FTP or e-mail
(SMTP).

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Catalyst 2950 switches can be configured either as command
or member switches in a Cisco switch cluster. The command
switch serves as the single-IP address management point and
disbursesall managementinstructionsdictated bythe network
administrator. Command switches can cluster up to 15
additional interconnected member switches regardless of
interconnection media. CMS also allows the network
administrator to designate a standby or redundant command
switch, which takes thecommander dutiesshould the primary
command switch fail.

Enhanced Security, Management, and Integrated Cisco IOS Features

Cisco Catalyst 2950 Series switches have several exceptional
features toincrease network performance, manageability,and
security. Network managers can implement higher levels of
data security and boost LAN performance by deploying up to
64 virtual LANs (VLANs) per switch. This ensures that data
packets are forwarded only to stations within a specific
VLAN, creating a virtual firewall between groups of ports on
the network and reducing broadcast transmission.
VLAN trunks can be created from any port using the
standards-based 802.1Q VLAN trunking architecture. Per
VLAN Spanning Tree (PVST+) allows users to implement
redundant uplinks while also distributing traffic loads across
multiple links. This is not possible with standard Spanning
Tree Protocol (STP) implementations. Cisco Uplink Fast
technology ensures immediate transfer to the secondary
uplink, much better than the traditional 30 to 60 second
convergence time. Thisis yetanother enhancement ofthe STP
implementation.

With Catalyst 2950 switches, network managers can
implement high levels of port and console security. Media
Access control (MAC) address-based port level security
prevents unauthorized stations from accessing the switch.
Static and dynamic address limits can be created, giving
administrators powerful control over network access.
Multilevel access security on the switch console prevents
unauthorized users from accessing or altering switch
configuration. Terminal access controller access control
system (TACACS+) authentication enables centralized
coordination of access control across a large group of
networking devices.

Features And Key Benefits

Exceptional Performance

• Wire-speed, nonblocking performance on all ports,
including Gigabit ports

• 8.8-Gbps switching fabric and 6.6 million
packets-per-second maximum forwarding rate ensures
maximum throughput—even for the most
performance-sensitive applications

• 12- or 24- 10BaseT/100BaseTX autosensing ports, each
delivering up to 200 Mbps of bandwidth to individual
users, servers or workgroups to support
bandwidth-intensive applications

• Catalyst 2950T-24 has two built-in, Gigabit Ethernet
(1000BaseT) ports that deliver up to 4 Gbps aggregated
bandwidth to the Gigabit Ethernet backbone, Gigabit
Ethernetservers or between switches—leveragingexisting
Category 5 cabling infrastructure—up to a distance of 100
meters

• Catalyst 2950C-24 switch has two multimode
(100BaseFX) fiber uplinks deliver up to 200 Mbps
of bandwidth over an extended distance of up to 2
kilometers

• 8 MB shared memory architecture ensures the highest
possible throughput with a design that eliminates
head-of-line blocking, minimizes packet loss,and delivers
better overall performancein environments with extensive
multicast and broadcast traffic

• 16 MB of DRAM and 8 MB of Flash on-board enable the
addition of future feature upgrades, maximizing customer
investments

• Bandwidth aggregation through Fast EtherChannel and
GigabitEtherChannel technologyenhancesfault tolerance
and offersup to 4Gbps of aggregatedbandwidth between
switches, to routers and to individual servers

• 802.1Q standards-based VLAN trunking on each port; 64
VLANs per switch with 64 instances of Spanning Tree
(PVST+)

• Superior multicast management via support for IGMP
snooping in hardware

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