The Cisco 805 – An Overview
1. Introduction
The Cisco 805 was a modular Ethernet switch that first appeared in the mid‑1990s. It was part of Cisco’s Catalyst 800 series, aimed at the enterprise edge and campus distribution layers. The device was known for its affordable price point, ease of configuration, and stack‑ability, which made it a common choice for universities, small‑to‑medium businesses, and legacy deployments.
2. Key Features
- 8 Gbps total switching fabric
- Supports 10/100 Mbps and optional 1000 Mbps copper or fiber ports
- Up to 128 VLANs, port security, and ACLs
- Quality‑of‑Service with priority queuing and policing
- Stacking through a dedicated port, allowing redundant paths
3. Architecture
The 805 was built around a dedicated forwarding engine that handled MAC learning and frame forwarding, backed by a dual‑processor control plane that ran IOS 12.0. The control plane managed configuration, routing protocols, and management tasks, communicating with the forwarding engine via an internal bus. Security features such as port security and optional IEEE 802.1X were integrated, while SNMP v1/v2c was available for monitoring.
4. Lifecycle
Discontinued in 2002 with end‑of‑life support ending in 2005. Cisco issued firmware updates until 2005, after which newer Catalyst series (6500, 3000, 2000) were recommended for migration.
5. Impact
The 805 helped standardize modular, stackable switch designs in enterprises and fostered VLAN‑based campus architectures. Its popularity in education systems provided hands‑on experience for students and contributed to early Internet expansion.
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Technical Specifications
*Physical Characteristics*
The Cisco 805 chassis measured 9 inches high, 8 inches wide, and 4 inches deep, fitting a single rack slot in a 19‑inch rack. It housed a built‑in 24 W power supply that could be hot‑swapped with modules up to 40 W. The CPU was a dual‑core 100 MHz processor, 128 MB of SDRAM for switching, and 64 MB for control plane tasks. Thermal sensors monitored fans, temperature, and voltage.
*Port and Bandwidth*
Variants offered eight, sixteen, or twenty‑four 10/100 Mbps copper RJ‑45 ports, with optional gigabit copper or fiber uplink ports. The 8 Gbps fabric delivered 400 Mbps per port on 100‑Mbps models and 1 Gbps on gigabit variants. Full‑duplex, priority‑based queueing, and 128 VLANs were supported. The stacking port provided aggregated bandwidth across devices.
*Forwarding and Memory*
The forwarding engine stored MAC tables in a dedicated memory pool, with the control plane processor handling routing and configuration. A 32 k route limit existed in later firmware, but Layer 3 features were minimal. The device supported RSTP and MSTP after firmware updates, reducing convergence times. However, IPv6 support remained unavailable.
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Architecture and Features
*Forwarding Engine*
At its core, the 805 used a modular fabric with a dedicated forwarding engine handling MAC learning, frame forwarding, and error checking. The forwarding engine’s memory pool stored forwarding tables and per‑port configuration entries. A separate control plane processor managed routing protocols, interface configuration, and management tasks, communicating via an internal bus.
*Software and Security*
The 805 ran Cisco IOS 12.0, providing CLI, web UI, and SNMP v1/v2c. Security features included port security, optional IEEE 802.1X, and ACLs for ingress/egress filtering. Quality‑of‑Service mechanisms allowed priority queues and traffic policing. Stacking via a dedicated port enabled redundant paths and aggregated bandwidth across multiple devices. RSTP/MSTP upgrades improved convergence and reliability.
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Management and Configuration
*CLI & Web*
Configuration accessed via the console port (RS‑232) using IOS syntax. Common tasks - interface config, VLAN assignment, STP tuning - were performed via hierarchical commands. The web UI offered dashboards for monitoring port status and basic configuration.
*SNMP & Firmware*
Community‑based SNMP v1/v2c was available for polling statistics, CPU usage, and environmental data. Firmware updates (IOS images) were loaded via TFTP or CD-ROM, requiring reboot. Minor releases fixed bugs related to VLAN handling, port flapping, and memory leaks, extending the device’s operational lifespan.
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Deployment Scenarios
*Campus & SMB*
Universities and corporate campuses used the 805 as a distribution layer, aggregating traffic from access switches. Its 128‑VLAN support enabled department isolation, labs, and service networks. SMBs employed it for cost‑effective gigabit connectivity across floors, with fiber uplinks extending reach to branches.
*Service Provider & Data Center*
Mid‑1990s service providers occasionally used the 805 as edge devices for small broadband deployments, leveraging stacking for uplink aggregation. In data centers, the 805 served as a low‑end core switch, connecting server blades to top‑of‑rack units. Its limited port density meant it suited smaller or legacy fabrics that needed simple, reliable switching.
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Lifecycle and Support
*End‑of‑Life*
Discontinued in 2002; support ended in 2005. Cisco offered extended warranty and support contracts during the transition. Migration to newer Catalyst models (6500, 3000, 2000) was advised for higher throughput and advanced routing.
*Legacy Challenges*
Legacy deployments faced limited firmware support, aging images, and difficulty sourcing spare parts. Migration to modern, software‑defined networking solutions became necessary to maintain reliability and security.
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Impact on Networking Practices
*Design Influence*
The 805’s stackable, modular design influenced later Cisco devices with advanced stacking protocols and redundant control planes. VLAN segmentation became a core practice in campus topology, encouraging hierarchical designs over flat broadcast domains.
*Educational & Internet Growth*
Educational institutions adopted the 805 for its reliability and simplicity, giving students hands‑on network configuration experience. The device also enabled early Internet expansion by connecting departmental servers, student workstations, and external research networks during the late 1990s.
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Common Issues and Troubleshooting
*Hardware Failures*
Power supplies were prone to thermal throttling and slot lock‑in failures. Fans could fail, causing overheating and shutdowns. Gigabit line cards were susceptible to slot lock‑in failures requiring mechanical inspection.
*Firmware Bugs & Performance*
Firmware bugs caused VLAN misconfigurations, STP instability, and memory leaks. Performance issues emerged under high load due to insufficient buffering, leading to frame drops. QoS priorities and disabling unused ports mitigated congestion.
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References
- Technical white paper, Cisco Systems, 1995, “Cisco 800 Series Ethernet Switches.”
- Cisco IOS Software Release Notes, 12.0, 1998.
- Network World article, 1996, “The Rise of Modular Switches.”
- IEEE Communications Magazine, 1999, “VLAN Deployment in Campus Networks.”
- Cisco Support Knowledge Base, 2005, “End‑of‑Life Notice for the Cisco 805.”
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