Product Overview

This chapter provides physical and functional overviews of the Cisco 7204 router. It contains physical descriptions of the router hardware and major components, and functional descriptions of hardware-related features. Descriptions and examples of software commands are included only when they are necessary for replacing, installing, configuring, or maintaining the router hardware.

The Cisco 7204 is part of the Cisco 7200 series routers, which consists of the Cisco 7204 and the Cisco 7206. The four-slot Cisco 7204 supports multiprotocol, multimedia routing and bridging with a wide variety of protocols and any combination of Ethernet, Fast Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), Asynchronous Transfer Mode (ATM), Integrated Services Digital Network (ISDN), and serial media.

Network interfaces reside on port adapters that provide the connection between the router's three Peripheral Component Interconnect (PCI) buses and external networks. The Cisco 7204 has four slots (slot 1 through slot 4) for the port adapters, one slot for an Input/Output (I/O) controller, and one slot for a network processing engine. You can place the port adapters in any of the four available slots.

There are bays for up to two AC-input or DC-input power supplies. The Cisco 7204 will operate with one power supply. While a second power supply is not required, it allows load sharing and increased system availability. The Cisco 7204 does not support a mixture of AC- and DC-input power.

The Cisco 7204 provides the following features:

Online insertion and removal (OIR)--allows you to add, replace, or remove port adapters without interrupting the system or entering any console commands.
Dual hot-swappable, load-sharing power supplies--provide system power redundancy; if one power supply or power source fails, the other power supply maintains system power without interruption. Also, when one power supply is powered off and removed from the router, the second power supply immediately takes over the router's power requirements without interrupting normal operation of the router.
Environmental monitoring and reporting functions--allow you to maintain normal system operation by resolving adverse environmental conditions prior to loss of operation.
Downloadable software--allows you to load new images into Flash memory remotely, without having to physically access the Cisco 7204 router, for fast, reliable upgrades.

Physical Description

The front of the Cisco 7204 provides access to an I/O controller and up to four network interface port adapters (see Figure 1-1). The I/O controller contains the following: a local console port for connecting a data terminal (or data terminal equipment [DTE]) and an auxiliary port for connecting a modem (or other data communications equipment [DCE]) or other devices for configuring and managing the router; two Personal Computer Memory Card International Association (PCMCIA) slots for Flash memory cards; an optional Fast Ethernet port. The Fast Ethernet port provides a 100-Mbps connection to the network.

Note The I/O controller is available with or without a Fast Ethernet port. Figure 1-1 shows an I/O controller with a Fast Ethernet port.

Figure 1-1: Cisco 7204 Router--Front View

The port adapters installed in the Cisco 7204 are of the same type as those installed on the second-generation Versatile Interface Processors (VIP2s) in the Cisco 7000 family routers. The port adapters installed in the Cisco 7204 support OIR. For an explanation of OIR, refer to the section "Online Insertion and Removal" later in this chapter.

Note The I/O controller does not support OIR. You must power down the Cisco 7204 before removing the I/O controller from the router.

Port adapter slots in the Cisco 7204 router are numbered from left to right, beginning with port adapter slot 1 and continuing through port adapter slot 4. Port adapter slot 0 is the Fast Ethernet port on the I/O controller (refer to Figure 1-2).

Note In Figure 1-1 and Figure 1-2, a blank port adapter is installed in the slot 3. To ensure adequate airflow across the port adapters, each port adapter slot must be filled with either a port adapter or a blank port adapter.

Figure 1-2: Port Adapter Slot Numbering

The rear of the Cisco 7204 router provides access to the network processing engine and up to two power supplies (refer to Figure 1-3).

Figure 1-3: Cisco 7204 Router--Rear View

Note The network processing engine does not support OIR. You must power down the Cisco 7204 before removing the network processing engine from the router.

The network processing engine has no external connectors or LEDs. There are two han dles for removing and installing the network processing engine and two captive installation screws for securing it to the chassis.

The Cisco 7204 router comes equipped with one 280W AC-input or one 280W DC-input power supply. A fully configured Cisco 7204 router operates with only one installed power supply; however, a second, optional power supply of the same type provides hot-swappable, load-sharing, redundant power. Figure 1-3 shows the rear of a Cisco 7204 router configured with a single AC-input power supply. (A power supply filler plate is installed over the second power supply bay.)

The power supply has the router's main power switch and either an AC-input power receptacle or a hardwired DC-input power cable (depending on the type of installed power supply). Adjacent to the power supply bays there are two chassis ground receptacles that provide a chassis ground connection for ESD equipment or a grounding wire (refer to Figure 1-3).

Caution Do not mix power supplies in the Cisco 7204. In dual power supply router configurations, both power supplies must be of the same type (two AC-input power supplies or two DC-input power supplies).

Three internal fans draw cooling air into chassis and across internal components to maintain an acceptable operating temperature. (Refer to Figure 1-3.) The three fans are enclosed in a tray that is located in the subchassis.

Caution To ensure the proper flow of cooling air across the internal components, make sure blank port adapters are installed in unoccupied port adapter slots, and power supply filler plates are installed in unoccupied power supply bays.

The I/O controller, port adapters, power supplies, and network processing engine slide into their respective chassis slots and connect directly to the router's midplane; there are no internal cables to connect. The midplane distributes DC power from the power supplies to the I/O controller, port adapters, fan tray, and network processing engine.

The midplane also identifies OIR of the port adapters, bridges the PCI buses from the port adapters to packet static random-access memory (SRAM) on the network processing engine, arbitrates traffic across the PCI buses, and generates the clock signals for the port adapters on each PCI bus.

The Cisco 7204 operates as either a tabletop or rack-mounted unit. A rack-mount kit is standard equipment included with all Cisco 7204 routers when they are shipped from the factory. The kit provides the hardware needed to mount the router in a standard 19-inch equipment rack or a Telco rack. Steps for installing the Cisco 7204 router in an equipment rack are explained in the chapter "Installing the Cisco 7204." If you are not rack-mounting your Cisco 7204, place it on a sturdy tabletop or platform.

A fully configured Cisco 7204, with two installed power supplies and all chassis slots filled, weighs approximately 50 pounds (22.7 kilograms [kg]). For clearance requirements and rack-mount installation considerations, refer to the section "Site Environment" in the chapter "Preparing for Installation."

System Spe cifications

Table 1-1 lists the Cisco 7204 router physical specifications and power requirements.

Table 1-1: Cisco 7204 Physical Specifications

Description	Specification
Midplane	Two primary PCI buses and one secondary PCI bus with an aggregate bandwidth of 600 Mbps¹
Dimensions (H x W x D)	5.25 in. x 16.8 in. x 17 in. (13.34 cm x 42.67 cm x 43.18 cm)
Weight	Chassis fully configured with a network processing engine, I/O controller, 4 port adapters, 2 power supplies, and a fan tray: ~ 50 lb (22.7 kg)
Heat dissipation	370W (1262 Btu²)
AC-input power	370W maximum (with either a single or dual power supply configuration)
AC-input voltage	100-240 VAC³ wide input with power factor correction
AC-input current rating	5A⁴ maximum at 110 VAC, and 2.5A maximum at 240 VAC with the chassis fully configured
AC-input cable	18 AWG⁵ three-wire cable, with a three-lead IEC-320 receptacle on the power supply end, and a country-dependent plug on the power source end
DC-output power	280W maximum (with either a single or dual power supply configuration)
DC-input power	370W maximum (with either a single or dual power supply configuration)
DC-input voltage	-48 VDC⁶ nominal in North America -60 VDC nominal in the European Community
DC-input current rating	14A maximum at -48 VDC 8A maximum at -60 VDC
DC voltages supplied and maximum, steady-state current ratings	+5.2V @ 30A +12.2V @ 9A -12.0V @ 1.5A +3.5V @ 13A
DC-input cable	14 AWG (2.08 mm2) recommended minimum, with at least three conductors rated for at least 140°F (60°C).
Frequency	50/60Hz⁷
Airflow	~80 cfm⁸
Temperature	32 to 104°F (0 to 40°C) operating; -4 to 149°F (-20 to 65°C) nonoperating
Humidity	10 to 90% noncondensing
Software requirement	Cisco IOS Release 11.1(5) or later for a Cisco 7204 with an installed NPE⁹-150 Cisco IOS Release 11.1(8) or later for a Cisco 7204 with an installed NPE-100 Cisco IOS Release 11.1(13a)CA1 or later for a Cisco 7204 with an installed NPE-200
Agency approvals	Safety: UL 1950, CSA 22.2 No. 950, EN60950, AUSTEL TS001, AS/NZS 3260 EMI: FCC Class A, CSA Class A, EN60555-2, EN55022 Class B, VCCI Class 2, AS/NRZ 3548 Class A Immunity: IEC-1000-4-2, IEC-1000-4-3, IEC-1000-4-4, IEC-1000-4-5, IEC-1000-4-6, IEC-1000-4-11, IEC 1000-3-2

¹ Mbps = megabits per second.
² Btu = British thermal units.
³ VAC = volts alternating current.
⁴ A = ampere.
⁵ AWG = American Wire Gauge.
⁶ VDC = volts direct current.
⁷ Hz = hertz.
⁸ cfm = cubic feet per minute.
⁹ NPE = Network processing engine.

Note For a chassis footprint, additional dimensions, and clearance requirements for the Cisco 7204 perimeter, refer to the section "Site Requirements" in the chapter "Preparing for Installation."

Field-Re placeable Units

The Cisco 7204 router is easy to service; all its major components are field replaceable units (FRUs). The following Cisco 7204 components are FRUs:

Network processing engine
Input/Output controller
Port adapters
Power supplies
Fan tray
Subchassis (including the midplane)
Chassis
Flash memory cards
Rack-mount and cable-management kit

The following sections provide brief overviews of each FRU. Instructions for removing and replacing FRUs are contained in separate documents called configuration notes. For example, If you need to replace the fan tray in your Cisco 7204 router, refer to the configuration note Cisco 7200 Series Subchassis and Fan Tray Replacement Instructions (Document Number 78-3228-xx). This configuration note accompanies every subchassis and fan tray shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

For ordering information, contact a customer service representative.

Network Proc essing Engine

The network processing engine maintains and executes the system management functions for the Cisco 7204 router. The network processing engine also shares the system memory and environmental monitoring functions with the I/O controller.

Note Detailed instructions for removing and replacing the network processing engine are contained in the configuration note Cisco 7200 Series Network Processing Engine Replacement Instructions (Document Number 78-3225-xx). This configuration note accompanies every network processing engine that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

The network processing engine is available in three versions: the NPE-100, NPE-150, and NPE-200. The network processing engines have the same functionality; however, their performance differs because of the microprocessor type and the amount of SRAM each network processing engine provides.

The network processing engines consist of the following components:

Reduced instruction set computing (RISC) microprocessor
- The NPE-100 and the NPE-150 have an R4700 microprocessor that operates at an internal clock speed of 150 megahertz (MHz).
- The NPE-200 has an R5000 microprocessor that operates at an internal clock speed of 200 MHz.
System controller that uses direct memory access (DMA) to transfer data between DRAM and packet SRAM on the network processing engine.
DRAM for storing routing tables, protocols, network accounting applications, packets of information in preparation for process switching, and packet buffering for SRAM overflow. The standard configuration is 32 megabytes (MB), with up to 128 MB available through single in-line memory module (SIMM) upgrades.
Packet SRAM for storing packets of information in preparation for fast switching.
- The NPE-100 does not have SRAM.
- The NPE-150 has 1 MB of SRAM.
- The NPE-200 has 4 MB of SRAM.
Unified cache SRAM that functions as the secondary cache for the microprocessor. (The primary cache is within the microprocessor.)
Two environmental sensors for monitoring the cooling air as it leaves the Cisco 7204 chassis.
Erasable programmable read-only memory (EPROM) for storing sufficient code for booting the Cisco IOS software. (This component is only available on the NPE-200.)

The two network processing engines perform the following system management functions:

Sending and receiving routing protocol updates
Managing tables, caches, and buffers
Monitoring interface and environmental status
Providing Simple Network Management Protocol (SNMP) management and the console/Telnet interface
Accounting and switching of data traffic
Booting and reloading images
Managing port adapters (recognition and initialization during OIR)

Figure 1-4 shows the NPE-100, Figure 1-5 shows the NPE-150, and Figure 1-6 shows the NPE-200.

Figure 1-4: Network Processing Engine--100

Figure 1-5: Network Processing Engine--150

Figure 1-6: Network Processing Engine--200

Table 1-2 lists the network processing engine memory components.

Table 1-2: Network Processing Engine Memory Components

Memory Type	Size	Quantity	Description	Location
DRAM	32 to 128 MB	2 or 4	16- or 32-MB SIMMs (based on maximum DRAM required)	Bank 0: U18 and U25 or U11 and U25¹ Bank 1: U4 and U12 or U42 and U52²
SRAM NPE-150 NPE-200	1 MB 4 MB	8 8	Eight chips, each being 128K words x 9 bits wide Eight chips, each being 512K words x 8bits wide	U700 through U703 U800 through U803 U6, U10, U13, U14, U28, U29, U38, and U39
Boot ROM³ (NPE-200 only)	256 KB	1	EPROM for the ROM monitor program	Socket U92
Unified cache	512 KB	4	Secondary cache for the R4700 and R5000 RISC processors	NPE-100 and NPE-150 U2, U10, U14, and U26 NPE-200 U16, U9, U109, and U107

¹ The sockets for bank 0 on the NPE-100 and the NPE-150 are numbered U18 and U25. The same sockets on the NPE-200 are numbered U11 and U25.
² The sockets for bank 1 on the NPE-100 and the NPE-150 are numbered U4 and U12. The same sockets on the NPE-200 are numbered U42 and U52.
³ ROM = read-only memory.

Note To prevent DRAM errors and to ensure your system initializes correctly at startup, DRAM bank 0 (socket U18 and U25, or U11 and U25) must contain no fewer than two SIMMs of the same type. You may also install two SIMMs of the same type in bank 1 (socket U4 and U12, or U42 and U52); however, bank 0 must always contain the two largest SIMMs.

Table 1-3 lists the network processing engine factory-installed DRAM configurations and their product numbers.

Table 1-3: DRAM SIMM Configurations

Total DRAM	DRAM Bank 0	Quantity	DRAM Bank 1	Quantity	Product Number
32 MB	U18 and U25 or U11 and U25	2 16-MB SIMMs	U4 and U12 or U42 and U52	-	MEM-NPE-32MB¹
32 MB	U18 and U25 or U11 and U25	2 16-MB SIMMs	U4 and U12 or U42 and U52	-	MEM-NPE-32MB¹	64 MB	U18 and U25 or U11 and U25	2 32-MB SIMMS	U4 and U12 or U42 and U52	-	MEM-NPE-64MB1
128 MB	U18 and U25 or U11 and U25	2 32-MB SIMMs	U4 and U12 or U42 and U52	2 32-MB SIMMs	MEM-NPE-128MB1	64 MB	U18 and U25 or U11 and U25	2 32-MB SIMMS	U4 and U12 or U42 and U52	-	MEM-NPE-64MB1

¹ These products are also available as DRAM upgrades. For example, to upgrade a network processing engine from 32 MB to 64 MB of DRAM, order product number MEM-NPE-32MB=. A 16 MB option (product number MEM-NPE-16MB=), which consists of two 8-MB SIMMs, is also available from the factory as a DRAM upgrade.

Input/Output C ontroller

The Input/Output controller shares the system memory functions and the environmental monitoring functions for the Cisco 7204 router with the network processing engine.

Note Detailed instructions for removing and replacing the I/O controller are contained in the configuration note Cisco 7200 Series Input/Output Controller Replacement Instructions (Document Number 78-3224-xx). This configuration note accompanies every I/O controller that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

The I/O controller is available with an optional Fast Ethernet port. Figure 1-7 shows an I/O controller without the Fast Ethernet port. Figure 1-8 shows an I/O controller with the Fast Ethernet port. The I/O controller consists of the following components:

Dual EIA/TIA-232 channels for local console and auxiliary ports. The console port has full DCE functionality and a DB-25 receptacle. The auxiliary port has full DTE functionality and a DB-25 plug.
An optional Fast Ethernet port with a single female MII receptacle that is configurable for 100 Mbps.
Nonvolatile random-access memory (NVRAM) for storing the system configuration and environmental monitoring logs. NVRAM uses lithium batteries to maintain its contents when disconnected from power.
Flash memory SIMM for storing the boot helper image.
Two PCMCIA slots for Flash memory cards, which contain the default Cisco IOS software image.
Erasable programmable read-only memory (EPROM) for storing sufficient code for booting the Cisco IOS software.
Two environmental sensors for monitoring the cooling air as it enters and leaves the Cisco 7204 chassis.

Figure 1-7: I/O Controller--Without Fast Ethernet Port

Figure 1-8: I/O Controller--With Fast Ethernet Port

Table 1-4 lists the I/O controller memory components.

Table 1-4: I/O Controller Memory Components

Memory Type	Size	Quantity	Description	Location
Boot ROM	256 KB	1	EPROM for the ROM monitor program	U20
Flash SIMM Flash memory card	4 MB 8 MB to 20 MB	1 Up to 2	Contains the default boot helper image Contains the default Cisco IOS image	U99 PCMCIA slot 0 and slot 1
NVRAM	128 KB	1	Nonvolatile EPROM for the system configuration file	U41

Depending on whether the Fast Ethernet port is present, either two or four LEDs on the I/O controller faceplate indicate system status; two additional LEDs indicate the status of the Flash memory cards installed in either PCMCIA slot.

Figure 1-9 shows the LEDs of an I/O controller that does not have the Fast Ethernet port. Figure 1-10 shows the LEDs of an I/O controller that has the Fast Ethernet port. Table 1-5 lists I/O controller LEDs and their functions. To use the LEDs for troubleshooting the I/O controller, refer to the section "Identifying Startup Problems" in the chapter "Troubleshooting the Installation."

Next to the IO power OK LED on the I/O controller faceplate is the CPU reset button. The CPU reset button resets the entire system.

Caution To prevent system errors and problems, use the CPU reset button only at the direction of your service representative.

Figure 1-9: I/O Controller LEDs and CPU Reset Button--Without Fast Ethernet Port

Figure 1-10: I/O Controller LEDs and CPU Reset Button--With Fast Ethernet Port

Table 1-5: I/O Controller LEDs

LED	Function
IO Power OK	Indicates that the I/O controller is on and receiving DC power from the router midplane. This LED comes on during a successful router boot and remains on during normal operation of the router.
Enabled	Indicates that the network processing engine and the I/O controller are enabled for operation by the system; however, it does not mean that the Fast Ethernet port on the I/O controller is functional or enabled. This LED comes on during a successful router boot and remains on during normal operation of the router.
FE enable	Indicates that the Fast Ethernet port on the I/O controller is initialized and enabled for operation by the system. This LED comes on after the I/O controller has been enabled and remains on during normal operation of the router.
FE link	Indicates that the Fast Ethernet port on the I/O controller is receiving a carrier signal from the network. This LED remains off during normal operation of the router, unless there is an incoming carrier signal.
Slot 0 Slot 1	Indicate which PCMCIA slot is in use by coming on when either slot is being accessed by the system. These LEds remain off during normal operation of the router.

Port Ada pters

The Cisco 7204 is shipped from the factory with up to four installed port adapters that provide a variety of network media types (based on your order). The port adapters connect directly to the router's midplane. Port adapters installed in the Cisco 7204 router support OIR.

For a description of OIR, refer to the section "Online Insertion and Removal" later in this chapter. For general instructions about how to remove and replace a port adapter, refer to the section "Replacing a Port Adapter" in the chapter "Maintaining the Cisco 7204."

Caution To ensure adequate airflow across the router's port adapters, a port adapter or a blank port adapter must be installed in each port adapter slot.

Note Detailed instructions for removing, replacing, and configuring the port adapter types supported by the Cisco 7204 are contained in the configuration note for the port adapter. For example, if you plan to replace a Token Ring port adapter in your Cisco 7204 router, refer the configuration note PA-4R Token Ring Port Adapter Installation and Configuration (Document Number 78-2661-xx). This configuration note accompanies every Token Ring port adapter that is shipped from the factory as installed item in a Cisco 7204 or as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

Power S upplies

The Cisco 7204 comes equipped with one 280W AC-input power supply or one 280W DC-input power supply. You must order the second power supply separately.

Caution Do not mix power supplies in the Cisco 7204. In dual power supply configurations, both power supplies must be of the same type (two AC-input power supplies or two DC-input power supplies).

Note Detailed instructions for handling and replacing the Cisco 7204 power supplies are contained in the configuration notes Cisco 7200 Series 280-Watt AC-Input Power Supply Replacement Instructions (Document Number 78-3227-xx) and Cisco 7200 Series 280-Watt DC-Input Power Supply Replacement Instructions (Document Number 78-3420-xx). These configuration notes accompany every 280W AC-input power supply and every 280W DC-input power supply that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

A handle on the AC and DC power supplies provides a grip point for removing and replacing the power supply. (Figure 1-11 shows the faceplate of the AC-input power supply. Figure 1-12 shows the faceplate of the DC-input power supply.) Two captive installation screws secure the power supply to the chassis and seat the power supply in the router midplane. A Power OK LED indicates that the power supply is delivering +5 VDC to the router midplane.

The AC-input power supply has a receptacle for an AC-input power cable. A modular power cable connects the AC-input power supply to the site AC power source. A cable-retention clip secures the power cable to the AC-input power supply.

The DC-input power supply has DC-input power leads that are hardwired to a DC-input terminal block. A cable tie is shipped with each DC-input power supply to secure the leads to the power supply faceplate and provide strain relief for the leads.

Figure 1-11: AC-Input Power Supply

Figure 1-12: DC-Input Power Supply

Caution To ensure adequate airflow across the router's power supplies, a power supply or a power supply filler plate must be installed in each power supply bay. Figure 1-3 shows a Cisco 7204 with an installed power supply filler plate.

Table 1-1 lists the AC-input and DC-input power supply system power specifications, including input voltage and operating frequency ranges.

Note Each AC-input power supply operating at 120 VAC requires a minimum of 5A service. We recommend powering the Cisco 7204 from a 15A receptacle at the power source.

Note Each DC-input power supply operating at -48 VDC in North America requires a minimum of 14A service. Each DC-input power supply operating at -60 VDC in the European Community requires a minimum of 8A service. We recommend powering the Cisco 7200 series routers from a 15A receptacle at the power source.

The Power OK LED goes off and the power supply will shut itself down when the internal DC voltages exceed allowable tolerances or the internal temperature of the power supply exceeds allowable tolerances. The power supply will remain in a shut down state until it is disconnected and reconnected to the source power, and then restarted with the power switch. The power switch turns the power supply on and starts the system. For a description of power-supply shutdown conditions and thresholds, refer to the section "Environmental Monitoring and Reporting Functions" in this chapter.

Fan T ray

The fan tray, shown in Figure 1-13, consists of three fans that are enclosed in a metal case. The fan tray is located in the subchassis and receives -12 VDC through a DC power harness that connects directly to the router midplane. You must remove the subchassis to access the fan tray.

Note Detailed instructions for removing and replacing fan tray are contained in the configuration note Cisco 7200 Series Subchassis and Fan Tray Replacement Instructions (Document Number 78-3228-xx). This configuration note accompanies every fan tray that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

Figure 1-13: Cisco 7204 Fan Tray

The fan tray draws cooling air in through the intake vent on the right side of the chassis (when viewing the router from the front), and moves the air across the internal components and out the exhaust vent on the left side of the chassis.

Figure 1-14 shows the air flow through the router.

Figure 1-14: Internal Air Flow--Top View

The left and right sides of the chassis must remain unobstructed to ensure adequate air flow and prevent overheating inside the chassis; we recommend at least three inches of clearance. (See the section "Site Requirements" in the chapter "Preparing for Installation.")

Temperature sensors on the network processing engine and I/O controller monitor the internal air temperature and send warning messages when the internal air temperature approaches a specified threshold. If the internal temperature exceeds the specified threshold, the system environmental monitor shuts down all internal power to prevent equipment damage from excessive heat.

Subch assis (including the Midplane)

The subchassis (shown in Figure 1-15) has one slot for the network processing engine, two bays for power supplies, and one slot for the fan tray. The subchassis also houses the router midplane. To replace the router midplane, you must replace the entire subchassis.

The port adapter side of the midplane has four plugs for the port adapters and one plug for the I/O controller. The power supply side of the midplane has two plugs for power supplies, a plug for the fan tray's power harness, and one plug for the network processing engine. The midplane distributes DC power to the router's internal components.

Note Detailed instructions for removing and replacing subchassis are contained in the configuration note Cisco 7200 Series Subchassis and Fan Tray Replacement Instructions (Document Number 78-3228-xx). This configuration note accompanies every subchassis that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

Figure 1-15: Cisco 7204 Subchassis--Top Down and Rear Views

Cha ssis

The Cisco 7204 chassis, shown in Figure 1-16, has four slots for the port adapters, one slot for the I/O controller, and one bay for the subchassis. To replace the chassis, you must remove all of the internal components, including the subchassis.

Note Because you must remove all the internal components when replacing the chassis, refer to the configuration notes that explain how to remove and replace the internal components. These configuration notes accompany every chassis that is shipped from the factory as a FRU. The configuration notes are also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

Figure 1-16: Cisco 7204 Chassis

Flash Mem ory Cards

The Cisco 7204 supports up to two installed Intel Series 2+ Flash memory cards.

Note To avoid potential problems when inserting spare Flash memory cards in your Cisco 7204, we recommend that you reformat all of your Flash memory cards on a Cisco 7204 running Cisco IOS Release 11.1(5)CA or later, during your regularly scheduled service times. The chapter "Maintaining the Cisco 7204" contains instructions that explain how to reformat a Flash memory card.

Flash memory (Flash memory cards and the Flash SIMM on the I/O controller) allows you to remotely load and store multiple system and boot helper images. You can download a new image over the network and then add the new image to Flash memory or replace existing files. You can also transfer images between Flash memory cards and the onboard Flash memory SIMM. You can then boot the router either manually or automatically from any of the stored images. Flash memory can also function as a TFTP server to allow other routers to boot remotely from stored images or copy them into their own Flash memory.

Note Detailed instructions for removing and replacing Flash memory cards and memory SIMMs are contained in the configuration note Cisco 7200 Series Memory Replacement Instructions (Document Number 78-3226-xx). This configuration note accompanies every Flash memory card that is shipped from the factory as a FRU. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO). Instructions for installing and removing a Flash memory card are also contained in the section "Installing and Removing a Flash Memory Card" in Chapter 6 of this guide.

Table 1-6 lists the Flash memory card options supported by the Cisco 7204.

Table 1-6: Flash Memory Card Options

Memory Size	Product Number
8 MB	MEM-I/O-FLC8M¹
8 MB	MEM-I/O-FLC8M¹	16 MB	MEM-I/O-FLC16M1
20 MB	MEM-I/O-FLC20M1

¹ These products are also available as Flash card upgrades. To order an upgrade, add an equal sign (=) after the product number, for example, MEM-I/O-FLC16M=.

Rack-Mount and Cable-Management Kit

The rack-mount and cable-management kit for the Cisco 7204 consists of rack-mount and cable-management brackets that are designed for mounting your router in 19-inch, four-post or Telco-type equipment racks and for relieving strain on port adapter interface cables that are installed on port adapters in the router. The kit is shipped with each Cisco 7204 and is also available as a single FRU.

For detailed instructions about how to install the rack-mount and cable-management brackets on your Cisco 7204, refer to the sections "Rack-Mounting the Cisco 7204" and "General Installation" in the chapter "Installing the Cisco 7204."

Functional Overview

This section provides a functional overview of the Cisco 7204. It describes the numbering and addressing of the port adapters for the router, the environmental monitoring and reporting functions, and online insertion and removal (OIR). These descriptions will help you become familiar with the capabilities of the Cisco 7204 router.

Port Adapter Slot and Log ical Interface Numbering

The four port adapters in the Cisco 7204 provide the connection between the router's three Peripheral Component Interconnect (PCI) buses, called mb0, mb1, and mb2, and external networks. Bus mb0 is for the optional Fast Ethernet port on the I/O controller, bus mb1 is for port adapter slots 1 and 3, and bus mb2 is for port adapter slots 2 and 4.

The port adapters are categorized as high, medium, and low bandwidth. The high and medium bandwidth port adapters should be evenly distributed between bus mb1 and bus mb2. Information on port adapter categories and bus configurations is contained in the configuration note Cisco 7204 Port Adapter Hardware Configuration Guidelines (Document Number 78-3642-xx). This configuration note accompanies every Cisco 7204 router that is shipped from the factory. The configuration note is also available on the Documentation CD-ROM and on Cisco Connection Online (CCO).

In the Cisco 7204, the port adapter slot number is the chassis slot in which a port adapter is installed, while the logical interface number is the physical location of the interface port on a port adapter. Port adapter slots are numbered from 1 through 4; port adaptor slot 0 is the Fast Ethernet port on the I/O controller. (Refer to Figure 1-2 for the numbering scheme of the port adapter slots.) The number of logical interfaces depends on the type of port adapter.

The Media Access Control (MAC)-layer or hardware address is a standardized data link layer address that is required for certain network interface types. These addresses are not used by other devices in the network; they are specific and unique to each port. The Cisco 7204 uses a specific method to assign and control the MAC-layer addresses of its port adapters. For a description of the MAC-layer address, refer to the section "MAC-Layer Address" later in this chapter.

Port adapter slots maintain the same slot number regardless of whether other port adapters are installed or removed. However, when you move a port adapter to a different slot, the port adapter's logical interface number changes to reflect the new slot number.

You can identify port adapter slots by using software commands to display information about a specific port adapter or for all port adapters in the Cisco 7204. To display information about all port adapter slots, use the show interfaces command. To display information about a specific port adapter slot, use the show interfaces command with the port adapter type and slot number in the format show interfaces (port adapter type and slot number/port number). If you abbreviate the command (sho int) and do not specify port adapter type and slot number (or arguments), the system interprets the command as show interfaces and displays the status of all port adapters and ports.

Following is an example of how the show interfaces command, used without arguments, displays status information (including the physical port adapter number) for each port adapter in the Cisco 7204. In the following example, most of the status information for each interface is omitted.

Router# sh int
FastEthernet0/0 is administratively up, line protocol is up
	Hardware is DEC21140, address is 0000.0000.0000 (bia 0000.0000.0000)
	Internet address is 1.1.1.3
	MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
	(display text omitted)
Fddi1/0 is administratively down, line protocol is down
	Hardware is MIF68840_MM, address is 0000.0000.0000 (bia 0000.0000.0000)
	Internet address is 1.1.1.0
	MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
	(display text omitted)
Ethernet2/0 is administratively up, line protocol is up
	Hardware is AmdP2, address is 0000.0000.0000 (bia 0000.0000.0000)
	Internet address is 1.1.1.7
	MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
	(display text omitted)

You can also use arguments such as the interface type (Ethernet, TokenRing, Fddi, and so forth) and the port address (slot/port) to display information about a specific interface only.

The following example shows the display for the first port on the Token Ring port adapter in port adapter slot 3:

Router# sh int tokenring 3/0
TokenRing3/0 is administratively down, line protocol is down
	Hardware is IBM2692, address is 0000.0000.0000 (bia 0000.0000.0000)
	Internet address is 1.1.1.8
	MTU 4464 bytes, BW 1600 Kbit, DLY 630 usec, rely 255/255, load 1/255
	Encapsulation SNAP, loopback not set, keepalive set (10 sec)
	ARP type: SNAP, ARP Timeout 04:00:00
	Ring speed: 16 Mbps
	(display text omitted)

For complete descriptions and instructions of the commands used to configure your Cisco 7204, refer to the Configuration Fundamentals Configuration Guide and Configuration Fundamentals Command Reference publications, which are available on the Documentation CD-ROM and on Cisco Connection Online (CCO), or in print.

MAC-Layer Address

All local-area network (LAN) interfaces (ports) require unique MAC-layer addresses, also known as hardware addresses. Typically, the MAC address of an interface is stored on a memory component that resides directly on the interface circuitry; however, the OIR feature requires a different method. For a description of OIR, refer to the section "Online Insertion and Removal" later in this chapter.

The OIR feature allows you to remove a port adapter and replace it with another identically configured one. If the new port adapter matches the port adapter you removed, the system immediately brings it on line. In order to allow OIR, an address allocator with a unique MAC addresses is stored in an EEPROM on the router midplane. Each address is reserved for a specific port and slot in the router regardless of whether a port adapter resides in that slot. The MAC addresses are assigned to the slots in sequence. The first address is assigned to slot 0, and the last address is assigned to slot 4. This address scheme allows you to remove port adapters and insert them into other routers without causing the MAC addresses to move around the network or be assigned to multiple devices.

Note that if the MAC addresses were stored on each port adapter, OIR would not function because you could never replace one port adapter with an identical one; the MAC addresses would always be different. Also, each time a port adapter was replaced, other devices on the network would have to update their data structures with the new address, which, if they did not do so quickly enough, could cause the same MAC address to appear in more than one device at the same time.

Note Storing the MAC addresses for every slot in one central location means the addresses stay with the memory device on which they are stored.

Online Insertion and Removal

All port adapters in the Cisco 7204 support online insertion and removal (OIR). This function allows you to install and replace port adapters while the router is operating; you do not need to notify the software or shut down the system power.

The following is a functional description of OIR for background information only; for specific procedures for installing and replacing a port adapter in a Cisco 7204 router, refer to the appropriate configuration note.

Caution The network processing engine and the I/O controller are required system components that cannot be removed if the router is operating. Removing the network processing engine or the I/O controller while the router is operating will cause the router to shut down or crash, and might damage or destroy memory files.

Each port adapter has a bus connector that connects it to the router's midplane. Each midplane connector has a set of tiered pins in three lengths. The pins send specific signals to the system as they make contact with the port adapter. The system assesses the signals it receives and the order in which it receives them to determine if a port adapter is being removed or inserted into the midplane. From these signals, the system determines whether to reinitialize a new interface or shut down a removed interface. For example, when inserting an port adapter, the longest pins make contact with the port adapter first, and the shortest pins make contact last. The system recognizes the signals and the sequence in which it receives them.

When you remove or insert a port adapter in a Cisco 7204 router, the midplane pins send signals to notify the system, which then performs as follows:

Rapidly scans the midplane for configuration changes.
Initializes all newly inserted port adapters, noting any removed interfaces and placing them in the administratively shut down state.
Brings all previously configured interfaces on the port adapter back to the state they were in when they were removed. Any newly inserted interfaces are put in the administratively shut down state, as if they were present (but not configured) at boot time. If a similar port adapter type is reinserted into a slot, its ports are configured and brought on line up to the port count of the original port adapter.

OIR functionality allows you to add, remove, or replace port adapters while the system is on line. This provides a method that is seamless to end users on the network, maintains all routing information, and ensures session preservation.

Environmental Monitoring and Reporting Functions

Environmental monitoring and reporting functions are controlled by the network processing engine and allow you to maintain normal system operation by identifying and resolving adverse conditions prior to loss of operation. The environmental monitoring functions constantly monitor the internal chassis air temperature and DC supply voltages and currents. Each power supply monitors its own voltage and temperature and shuts itself down if it detects a critical condition within the power supply. If conditions reach shutdown thresholds, the system shuts down to avoid equipment damage from excessive heat. The reporting functions periodically log the values of measured parameters so that you can retrieve them for analysis later, and the reporting functions display warnings on the console if any of the monitored parameters exceed defined thresholds.

Environmental Monitoring

The environmental monitoring functions use the following levels of status conditions to monitor the system. Four sensors, two on the network processing engine and two on the I/O controller, monitor the temperature of the cooling air as it moves through the chassis. Table 1-7 lists the temperature thresholds for the processor-monitored levels of a Cisco 7204 router that has an installed network processing engine 150 (NPE-150). Table 1-8 lists the temperature thresholds for the processor-monitored levels of a Cisco 7204 router that has an installed NPE-100 or NPE-200.

Table 1-7: Typical Processor-Monitored Temperature Thresholds (NPE-150)

Parameter	High Warning	High Critical	Shutdown
Chassis inlet	104°F (40°C)	122°F (50°C)	-
Chassis outlet 1	109°F (43°C)	127°F (53°C)	136°F (58°C)
Chassis outlet 2	167°F (75°C)	167°F (75°C)	-
Chassis outlet 3	131°F (55°C)	149°F (65°C)	158°F (70°C)

Table 1-8: Typical Processor-Monitored Temperature Thresholds (NPE-100 or NPE-200)

Parameter	High Warning	High Critical	Shutdown
Chassis inlet	104°F (40°C)	122°F (50°C)	-
Chassis outlet 1	109°F (43°C)	127°F (53°C)	136°F (58°C)
Chassis outlet 2	167°F (75°C)	167°F (75°C)	-
Chassis outlet 3	122°F (50°C)	140°F (60°C)	149°F (65°C)

Table 1-9 lists the DC power thresholds for the normal, warning, and critical (power supply-monitored) levels.

Normal--All monitored parameters are within normal tolerances.
Warning--The system has exceeded a specified threshold. The system will continue to operate, but operator action is recommended to bring the system back to a normal state.
Critical--An out-of-tolerance temperature or voltage condition exists. The system will continue to operate; however, the system is approaching shutdown. Immediate operator action is required.
Shutdown--The processor has detected a temperature condition that could result in physical damage to system components and has disabled DC power to all internal components. Requires immediate operator action. All DC power will remain disabled until you toggle the power switch. Before any shutdown, the system logs the status of monitored parameters in NVRAM so you can retrieve it later to help determine the cause of the problem.
Power supply shutdown--The power supply detected an internal out-of-tolerance overvoltage, overcurrent, or temperature condition and shut itself down. All DC power will remain disabled until you toggle the power switch.

Table 1-9: Typical Power Supply-Monitored DC-Voltage Thresholds

Parameter	Low Critical	Low Warning	High Warning	High Critical
+3.45V	+3.26V	+3.34V	+3.55V	+3.63V
+5.15V	+4.86V	+4.99V	+5.31V	+5.43V
+12.15V	+11.39V	+11.67	+12.62V	+12.91V
-11.95V	-9.52V	-10.73	-13.16V	-14.38V

If the air temperature exceeds a defined threshold, the system controller displays warning messages on the console terminal and, if the temperature exceeds the shutdown threshold, it shuts down the system. The system stores the present parameter measurements for both temperature and DC voltage in NVRAM, so that you can retrieve them later as a report of the last shutdown parameters.

The power supplies monitor internal power supply temperature and voltages. A power supply is either within tolerance (Normal) or out of tolerance (Critical), as shown in Table 1-9. If an internal power supply temperature or voltage reaches a critical level, the power supply shuts down without any interaction with the system processor.

Reporting Functions

The Cisco 7204 displays warning messages on the console if chassis interface-monitored parameters exceed a desired threshold. You can also retrieve and display environmental status reports with the show environment, show environment all, show environment last, and show environment table commands. Parameters are measured and reporting functions are updated every 60 seconds. A brief description of each of these commands follows.

Caution To prevent overheating the chassis, ensure that your system is drawing cool inlet air. Overtemperature conditions can occur if the system is drawing in the exhaust air of other equipment. Ensure adequate clearance around the sides of the chassis so that cooling air can flow through the chassis interior unimpeded and exhaust air exits the chassis and is not drawn into the inlet vent of other device.

The show environment command display reports the current environmental status of the system. The report displays parameters that are out of the normal values. No parameters are displayed if the system status is normal. The example that follows shows the display for a system in which all monitored parameters are within normal range:

Router# show env
All measured values are normal

If the environmental status is not normal, the system reports the worst-case status level. Following is an example overvoltage warning:

Router# show env
Warning: +3.45 V measured at +3.83 V

The show environment last command retrieves and displays the NVRAM log, which shows the reason for the last system shutdown (if the shutdown was related to voltage or temperature) and the environmental status at that time. Air temperature is measured and displayed, and the DC voltage supplied by the power supply is also displayed.

Following is sample output of the show env last command:

Router# show env last
Temperature readings:
	chassis inlet previously measured at 27C/80F
	chassis outlet 1 previously measured at 31C/87F
	chassis outlet 2 previously measured at 37C/98F 
	chassis outlet 3 previously measured at 45C/113F
Voltage readings:
	+3.45 V previously measured at +3.51 V 
	+5.2 V  previously measured at +5.19 V 
	+12.2 V previously measured at +12.42 V 
	-12.2 V previously measured at -12.14 V 
Reason for last shutdown:
	power supply

The show environment table command displays the temperature and voltage thresholds for each temperature sensor and for each monitored status level, which are related to those thresholds listed in Table 1-7, Table 1-8, and Table 1-9. The display also lists the shutdown threshold for the system.

Following is sample output of the sh env table command for a Cisco 7204 that has an installed NPE-150:

Router# show env table
Sample Point      LowCritical    LowWarning     HighWarning    HighCritical
chassis inlet                                   40C/104F       50C/122F
chassis outlet 1                                43C/109F       53C/127F
chassis outlet 2                                75C/167F       75C/167F
chassis outlet 3                                55C/131F       65C/149F
+3.45 V           +3.26          +3.34          +3.55          +3.63
+5.15 V           +4.86          +4.99          +5.31          +5.43
+12.15 V          +11.39         +11.67         +12.62         +12.91
-11.95 V          -9.52          -10.73         -13.16         -14.38
System shutdown for chassis outlet 1 58C/136F
System shutdown for chassis outlet 3 70C/158F

Following is sample output of the sh env table command for a Cisco 7204 that has an installed NPE-100 or NPE-200:

Router# show env table
Sample Point      LowCritical    LowWarning     HighWarning    HighCritical
chassis inlet                                   40C/104F       50C/122F
chassis outlet 1                                43C/109F       53C/127F
chassis outlet 2                                75C/167F       75C/167F
chassis outlet 3                                50C/122F       60C/140F
+3.45 V           +3.26          +3.34          +3.55          +3.63
+5.15 V           +4.86          +4.99          +5.31          +5.43
+12.15 V          +11.39         +11.67         +12.62         +12.91
-11.95 V          -9.52          -10.73         -13.16         -14.38
System shutdown for chassis outlet 1 58C/136F
System shutdown for chassis outlet 3 65C/149F

Note Temperature ranges and values are subject to change.

The show environment all command displays an extended report that includes temperature readings and voltage readings. The show environment all command also displays a report showing which power supply slots are occupied and which are empty.

Following is sample of the sh env all command:

Router# show env all
Power Supplies:
	Power supply 1 is Zytek AC Power Supply. Unit is on.
	Power supply 2 is Zytek AC Power Supply. Unit is on. 
Temperature readings:
	chassis inlet    measured at 47C/116F:Temperature in Warning range!
	chassis outlet 1 measured at 49C/120F:Temperature in Warning range!
	chassis outlet 2 measured at 55C/131F 
	chassis outlet 3 measured at 58C/136F:Temperature in Warning range!
Voltage readings:
	+3.45 V  measured at +3.51 V 
	+5.2 V  measured at +5.19 V 
	+12.2 V measured at +12.42 V 
	-12.2 V measured at -12.14 V

Fan Failures

When the system power is on, all three fans should be operational. The system will continue to operate if a fan fails; however, if the air temperature exceeds a defined threshold, the system controller displays warning messages on the console terminal and, if the temperature exceeds the shut down threshold, it shuts down the system.

If the system does shutdown because the temperature exceeded the shutdown threshold, the system will display the following message on the console screen and in the environment display when the system restarts:

Queued messages:
%ENVM-1-SHUTDOWN: Environmental Monitor initiated shutdown

For complete descriptions and instructions of the environmental monitor commands, refer to the Configuration Fundamentals Configuration Guide and Configuration Fundamentals Command Reference publications, which are available on the Documentation CD-ROM and on Cisco Connection Online (CCO), or in print.

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