Cisco Catalyst

Catalyst is the brand for a variety of network switches sold by Cisco Systems. While commonly associated with Ethernet switches, a number of different interfaces have been available throughout the history of the brand. Cisco acquired several different companies and rebranded their products as different versions of the Catalyst product line. The original Catalyst 5000 and 6000 series were based on technology acquired from Crescendo Communications. The 1700, 1900, and 2800 series Catalysts came from Grand Junction Networks, and the Catalyst 3000 series came from Kalpana in 1994.^[1]

In addition, Cisco increasingly offers routers with switching capabilities; for example the Cisco 7600 series routers and the Catalyst 6500 series L3–switches have interchangeable parts. Even Cisco′s smaller routers, including their newest “ISR” series, can have switch modules installed in them, basically making Cisco′s smaller switches fully integrated devices.

Operating systems

In most cases, the technology for the Catalyst Switch was developed separately from Cisco′s router technology. The Catalyst switches originally ran software called CatOS rather than the more widely known Cisco IOS software used by routers. However, this has changed as the product lines have merged closer together. In some cases, particularly in the modular chassis switches, a configuration called 'Hybrid' has emerged - this is where the layer 2 functions are configured using CatOS, and the layer 3 elements are configured using IOS. 'Native IOS' can also be found with newer software versions that have eliminated CatOS entirely in favor of IOS, even on hardware that originally required CatOS.

The latest version of IOS for the Catalyst 6500 series is 12.2(33)SXJ which enables In-Service Software Upgrade (ISSU) via IOS Software Modularity and 15.1.1-SY.

Some newer Catalyst switch models (with recent versions of the Cisco IOS) also allow configuration via web-based graphical interface (GUI) module which is hosted on a HTTP server located on the switch. The IOS config-mode command 'ip http-server' will enable this style of configuration. In series 12.x IOS, 'ip http-server' is always on as a factory default. The Catalyst 3750-series of switches is an example of a Cisco Catalyst switch that allows this style of GUI configuration via HTTP.

Some newer models of Catalyst switches (called Catalyst Express) no longer allow access to IOS or CatOS at all - these switches can only be configured by using a GUI.

CatOS

CatOS (Catalyst Operating System) is the discontinued operating system for many of the Catalyst brand of legacy network switches. It was originally called "XDI"^[2] by the switching company Crescendo Communications, Inc. Cisco renamed it to CatOS when they acquired Crescendo in late 1993.

CatOS ran on switches such as 1200, 2948G, 4000, 4500, 5000, 5500, 6000, 6500 series. CatOS can still run on some of Cisco's modular switches, "hybrid" mode. In hybrid mode, the NMP (switch processor) runs CatOS and the route processor runs Cisco IOS.

Interfaces

As Catalyst devices are primarily Ethernet switches, all modern Catalyst models have Ethernet interfaces, ranging from 10 Mbit/s to 10 Gbit/s depending on the model. Some models can accommodate Asynchronous Transfer Mode interfaces which can be used to bridge Ethernet traffic across wide area networks. Other models can support T1, E1, and ISDN PRI interfaces to provide connections to the PSTN. Legacy models supported a variety of interfaces, such as token ring, FDDI, and 100BaseVG, but are no longer sold by Cisco Systems.

Most models have basic layer 2 functions and are capable of switching Ethernet frames between ports. Commonly found additional features are VLANs (Cisco proprietary ISL or IEEE 802.1Q), trunking and QoS or CoS. The switches, whether IOS or CatOS, are fully manageable.

Many Catalysts that run IOS are also capable of functioning as a router, making them layer 3 devices; when coupled with TCP and UDP filtering, these switches are capable of layer 2-4 operation. Depending on the exact software image, a Catalyst that runs IOS may be able to tackle large-scale enterprise routing tasks, using router technologies like OSPF or BGP.

Most chassis-based Catalyst models have the concept of field-replaceable "supervisor" cards. These work by separating the line cards, chassis, and processing engine (mirroring most Cisco router designs). The chassis provides power and a high-speed backplane, the line cards provide interfaces to the network, and the processing engine moves packets, participates in routing protocols, etc. This gives several advantages:

• If a failure occurs, only the failed component needs to be replaced (typically a line card or supervisor). This means faster turnaround than having to uncable, unbolt, pull out, replace, re-bolt, and re-cable an entire switch, which may be as large as a quarter-rack, weigh over 150 pounds, and service over 500 cables.
• A redundant supervisor engine may be installed to rapidly recover from supervisor failures. This is subject to restrictions (as some switches don't support redundant supervisors), but typically results in restoration times under 90 seconds.
• A supervisor engine may be upgraded after purchase, increasing performance and adding features without losing any investment in the rest of the switch.

Additionally, most high-end switches off-load processing away from the supervisors, allowing line cards to switch traffic directly between ports on the same card without using any processing power or even touching the backplane. Naturally, this can't be done for all traffic, but basic layer-2 switching can usually be handled exclusively by the line card, and in many cases also more complex operations can be handled as well.

Management

Cisco switches are very popular for a number of reasons, including advanced customization and manageability. The switches can be configured using a serial console or a telnet session (or ssh if the correct OS is loaded along with the ssh keys generated). SNMP allows monitoring of many states, and measurement of traffic flows. Many devices can also run an HTTP server, but this is often disabled because of the security problems it creates - either because it's not encrypted, or because of the relatively frequent security vulnerabilities in the Cisco http daemon itself. Some Cisco switches focused on smaller organizations forego a command line interface and offer ONLY a browser-based GUI for configuration and management.

Configuration of the switch is done in plain text and is thus easy to audit - no special tools are required to generate a useful configuration. For sites with more than a few devices it is useful to set up a TFTP server for storing the configuration files and any IOS images for updating. Complex configurations are best created using a text editor (using a site standard template), putting the file on the TFTP server and copying it to the Cisco device. However, it can be noted that a TFTP server can present its own security problems.

Stackwise

Cisco StackWise is a technology offered by Cisco Systems that allows for up to nine Catalyst switch 3750 series switches to operate as though they were one switch. This allows for greater resiliency, and performance.

With a dual redundant loop back plane connection at either 32 Gbit/s or 64 Gbit/s depending on the 3750 model.

One switch from the stack will act as the master switch. The master switch will maintain the stack and allow you to configure and monitor the whole stack as though one via a single console.

If one switch fails the remaining switches will continue to operate by looping back any information that would normally traverse the failed switch, effectively bypassing it. If the master switch fails, the next switch in the stack will automatically take over as master. This feature means greater redundancy, as one switch's failure will not bring about a failure of the entire stack.

As each switch contains the entire configuration for the stack, one of the benefits of this technology is the ability to replace a faulty switch (any—including master) with a new un-programmed switch. The stack will configure the new switch on-the-fly to accommodate minimal downtime and reduce manual input configuration errors.

StackWise effectively replaced the GigaStack found on lower-price models such as Catalyst 35xx and 29xx series.

Recently, there is a new variation of the technology, known as Cisco Stackwise Plus, offering 64 Gbit/s nonblocking switching fabric speed.

Master Selection

The master switch of a stack is determined in the following order:^[3]

1. User specified.
2. The switch with the most advanced IOS, i.e. Advanced IP Services IPv6 (AIPv6), then Enhanced Multilayer Software Image (EMI) and then Standard Multilayer Software Image (SMI).
3. Programmed switch. A configured switch will preside over a switch with just the defaults.
4. Uptime. The switch that has been running the longest.
5. MAC address. The switch with the lowest MAC address.

Models

There are two general types of Catalyst switches: fixed configuration models that are usually one or two rack units in size, with 12 to 80 ports; and modular switches in which virtually every component, from the CPU card to power supplies to switch cards, are individually installed in a chassis.

In general, switch names start with WS-C, followed by the model line (2960). A letter at the end of this number signifies a special feature, followed by the number of ports (usually 24 or 48) and additional nomenclature indicating other features.

Fixed configuration switches

As of 2011, the most popular fixed configuration switches are the WS-C2960, WS-C3560 and WS-C3750 series at the high end, an entry level managed "express" series - with models beginning WS-CE (configurable by web interface only, no command line interface), the "ME" metroline series of switches, and a new "Small Business" series coming from Cisco's acquisition of Linksys. In addition, there are many legacy switches suitable for most business and service provider needs no longer offered directly through Cisco (WS-C2950, WS-C3550 for example).

Cisco Catalyst 2960 Series

Layer 2 switch.

• 2960 - WS-C2960 and WS-C2960PD are available in various configurations as indicated by model names TT-L, TC-L, TC-S, -S, TT-S, PST-L, PC-L, LT-L, PST-S, PC-S and LC-S: 8, 24 or 48 ports; LAN Base or LAN Lite; with and without Power over Ethernet (PoE); uplink of 10/100/1000BASE-T, SFP, or dual purpose.^[4]
• 2960G
• 2960-S
• 2960-SF
• 2960-X
  • 2960-X
  • 2960-XR

Cisco Catalyst 3560

Layer 2 and layer 3 switch.

Cisco Catalyst 3750

Layer 2 and layer 3 switch.

Modular switches

Cisco modular switches are much larger and are entirely configurable, beginning with a chassis, power supplies, the choice of supervisory engines (CPU mainboards), and switch modules. Among Cisco's modular series are:

• The 1000 switch family is considered an edge device, having many functionalities that can be built as the device is very modular. The 1900 line as a whole is past end-of-sale and end-of-life, and is considered a retired product line.^[5]
  

  The inside of a Cisco 1900-series switch
  • 1700: 24 10BaseT ports, 1 switchable MDI/MDIX uplink 10baseT/AUI/BNC port, and 2 Fast Ethernet ports. Runs neither CatOS nor IOS. Is a first-generation carryover from Cisco's acquisition of Grand Junction Networks.
  • 19xx: 12 or 24 10BaseT ports and 2 Fast Ethernet ports. ISL trunking on the 100 Mbit/s ports. Runs neither CatOS nor IOS.
• The Cisco Catalyst 3000 and 3100 series switches are switches for use in blade-enclosures: the Catalyst 3032 is a Layer2 switch and the Catalyst 3130x and 3130G are blade-switches for the Dell M1000e enclosure.
• The Cisco Catalyst 4500 Series is a mid-range modular chassis network switch. The system comprises a chassis, power supplies, one or two supervisors, line cards and service modules. The Series includes the E-Series chassis and the Classic chassis which is manufactured in four sizes: ten-slot, seven-slot, six-slot, and three-slot.
• The Cisco Catalyst 4900 series is a fixed-configuration switch. Uplink interfaces are either SFP ports or 10 Gigabit Ethernet, with 48 copper ports of 10/100/1000 Ethernet.
• The Cisco Catalyst 5500 Series and Cisco Catalyst 5000 Series is a chassis-based switch family. The Cisco Catalyst 5000 Series is acquired from another company. This entire series has now reached end-of-sale.
• The Cisco Catalyst 6500 Series is a chassis-based switch family. This series can support interfaces up to 10 Gigabit Ethernet in speed and redundant Supervisor modules.

End-of-Life Switches

Base Model	Form Factor	Variants	Available ports/Modules	Number of power supplies	Number/Type of supervisors	Expansion type	Sync	End-of-life (only major notices listed)	Comments
Catalyst 2940[6]	Fixed	2940	8 8P8C/1 8P8C 8 8P8C/1 8P8C or 1 SFP[7]	1 (fixed)	None	None	None	Announced 2009[8]
Catalyst 2950[9]	Fixed	2950 2950SX[10]	12 8P8C 24 8P8C 24 8P8C/2 GBIC or 1000SX 48 8P8C/2 GBIC or 1000SX[11]	1 (fixed)	None	None	None	Announced 2007[12]	Optional 'Gigastack' modules[13]
Catalyst 3550	Fixed	3550	24 8P8C/2 GBIC 48 8P8C/2 GBIC	1 (fixed)	None	None	None	Announced 2005[14]	PoE optional, optional 'Gigastack' modules[15]

Current Switches

Base Model	Form Factor	Variants	Available ports/Modules	Number of power supplies	Number/Type of supervisors	Expansion type	Sync	End-of-life (only major notices listed)	Comments
Catalyst 2900[16]	Fixed	2918 2926 2948 2980[17]	24 8P8C 48 8P8C		None	None	None	Announced 2007 (all except 2918),[18] Announced 2015 (2918 only)
Catalyst 2960[19]	Fixed	2960 2960S[20] 2960CX[21] 2960-X 2960-XR[22]	8 8P8C/2 SFP 24 8P8C/2 SFP 48 8P8C/4 SFP	1 (fixed) (*note: cannot stack power, only backplane)	None	None	Stack (up to four 2960-S, up to 8 2960-X or 2960XR)	Announced 2013 (2960 only)[23]	PoE only available on models with 'P' designator, 2960C is compact version
Catalyst 3560[24]	Fixed	3560 3560V2 3560E[25] 3560C[26]	8 8P8C/2 SFP or 8P8C 12 8P8C/2 SFP or 8P8C 8 SFP 12 SFP 24 8P8C/2 SFP 48 8P8C/4 SFP 12 'X2'[27] 12 SFP/2 'X2'	1 (up to 2 on 3560E only)	None	None (10 Gbit/s options on 3560E only)[28]	Stack (V2 and E only)	Announced 2012 (all except 3560C)[29]	PoE optional, 3560C is compact version
Catalyst 3650[30]	Fixed	3650[31]	24 8P8C/4 SFP 48 8P8C/4 SFP 24 8P8C/2 SFP+ 48 8P8C/2 SFP+		None	None	3650 is 3850 without stacking capability	No EoL notices announced to date	PoE optional
Catalyst 3750[32]	Fixed	3750 3750V2 3750G[33]	12 SFP 24 8P8C/2 SFP 48 8P8C/4 SFP	1 (up to 2 on 3750V2)	None	None	All are stack capable	Announced 2010 (3750),[34] Announced 2013 (3750V2)[35]	PoE optional
Catalyst 3750X[36]	Fixed	3750X	12 SFP 24 8P8C/2 SFP 48 8P8C/4 SFP	2	None	Uplink module with 1- and 10-Gbit/s options[37]	All are stack capable	Announced 2015[38]	PoE optional
Catalyst 3850[39]	Fixed	3850	12 SFP 24 8P8C 48 8P8C 12 SFP+ 16 SFP+ 24 SFP+ 32 SFP+ 48 SFP+[40]	Up to 2, most capable of stacking power	None	1 Gbit/s, 10 Gbit/s and 40 Gbit/s options on all models[41]	All are stack capable	No EoL notices announced to date	PoE optional
Catalyst 4500[42]	Chassis	4503 4503-E 4506 4506-E 4507R 4507R+E 4507R-E 4510R 4510R+E 4510R-E[43]	24 SFP module 48 SFP module 48 8P8C module	up to 2	4503:1, 4506:1, all else:up to 2[44] Sup II+, Sup III, Sup IV, Sup V (EoSale), Sup 6-E Sup 7-E, Sup 8-E[45]	Line cards	VSS (with Sup7)	Announced 2010 (non-E line cards),[46] Announced 2010 (non-E chassis),[47] Announced 2012 (Supervisor V),[48] Announced 2014 (Supervisor 6-E, Supervisor 6L-E)[49]	PoE optional (per module)
Catalyst 4500-X[50]	Fixed	4500-X	16 SFP+ 32 SFP+[51]	up to 2	None	8 SFP+ module	None	No EoL notices to date	Can select front to back or back to front air flow options
Catalyst 4900M[52]	Fixed	4900M	48 8P8C/4 SFP 48 8P8C/2 'X2' 28 SFP/2 'X2'	up to 2	None	Various 'X2' modules	None	No EoL notices to date
Catalyst 6500-E[53]	Chassis	6503-E 6504-E 6506-E 6509-E/V-E 6513-E[54]	4 port, 8 port, 16 port, 24 port and 48 port modules in 10/100/1G/10G/40G speeds of various physical medium[55]	up to 2	6503:1, all else:up to 2[56] Sup 2T, Sup 720 VSS, Sup 720, Sup 32 (EoSale)[57]	Line cards, Firewall, Wireless, Network Analysis (NAM), VPN, Application control engine, ASA Services[58]	VSS (with Sup 720-10G or Sup 2T)[59]	Announced 2012 (Supervisor 32),[60] Announced 2012 (6513 chassis (non-e))[61]	PoE optional (per module)
Catalyst 6800[62]	Both (6840-X and 6800ia models are fixed)	6880-X 6840-X 6800-XL 6800-ia						No EoL notices to date	Can support some 6500 modules (ASA, NAM, WiSM)[63]

Sources

• Cisco Systems Fourth Quarter and Fiscal Year 2006 Earnings
• Cisco's Catalyst 6500 Remains the Network hhSwitch to Beat
• 10-Gigabit Ethernet Poised To Take Data Centers By Storm

References

1. Kennedy Clark; Kevin Hamilton (Feb 1, 2002), Configuring the Catalyst, Cisco Press, retrieved 2016-08-29
2. Cisco Press: Configuring the Catalyst
3. "Cisco StackWise and StackWise Plus Technology". Cisco Systems. Retrieved 28 May 2016.
4. "Cisco Catalyst 2960 Series Switches: Compare Models", Cisco Systems. Accessed 4 March 2015.
5. Cisco.com: "End-of-Sale and End-of-Life Products". Retrieved December 21, 2012.
6. Cisco 2940 Product Line
7. Cisco 2940 Model comparison
8. Cisco 2940 EoL announcement
9. Cisco 2950 product line
10. Cisco 2950 Model Comparison
11. Cisco 2950 EoL notices
12. Cisco 2950 EoL announcement
13. Cisco Gigastack product information
14. Cisco 3550 EoL announcement
15. Cisco Gigastack product information
16. Cisco 2900 Product Line
17. Cisco 2900 EoL notifications
18. Cisco 2900 EoL notification
19. Cisco 2960 Product Line
20. Cisco 2960 Model Comparison
21. Cisco 2960CX Model Comparison
22. Cisco 2960 Migration Benefits
23. Cisco 2960 EoL announcement
24. Cisco 3560 Product Line
25. Cisco 3560 Model Comparison
26. Cisco 3560C Model Comparison
27. Cisco X2 module information
28. Cisco 3560E product information
29. Cisco 3560 EoL announcement
30. Cisco 3650 Product Line
31. Cisco 3650 Model Comparison
32. Cisco 3750 Product Line
33. Cisco 3750 Model Comparison
34. Cisco 3750 EoL Announcement
35. Cisco 3750V2 EoL Announcement
36. Cisco 3750X Product Line
37. Cisco Catalyst 3750-X and 3560-X Series Switches Data Sheet
38. Cisco 3750X EoL Announcement
39. Cisco 3850 Product Line
40. Cisco 3850 Model Comparison
41. Cisco 3850 optional hardware
42. Cisco 4500 Product Line
43. Cisco 4500-E Model Comparison
44. Cisco 4500-E Chassis specifications
45. Cisco 4500 Supervisor list
46. Cisco 4500 non-E line card EoL announcement
47. Cisco 4500 Non-E EoL announcement
48. Cisco 4500 Supervisor V EoL announcement
49. Cisco 4500 Supervisor 6E EoL announcement
50. Cisco 4500-X Product Line
51. Cisco 4500-X Model Comparison
52. Cisco 4900 Product Line
53. Cisco 6500-E Product Line
54. Cisco 6500-E Model Comparison
55. Cisco 6500 Line Card comparison
56. Cisco 6500 Model Comparison
57. Cisco 6500 Supervisor Comparison
58. Cisco 6500 Service module reference
59. Cisco 6500 VSS configuration
60. Cisco 6500 Supervisor 32 EoL notification
61. Cisco 6513 non-E chassis EoL announcement
62. Cisco 6800 Product Line
63. Cisco 6807-XL product information

External links

• Cisco Systems
• Cisco's Product Documentation Website for Catalyst Switches
• Cisco-centric Open Source Community