The highlighted components in all three Cisco UCS server models (5108 B-Series Blade Server Chassis, X9508 X Series Modular Server Chassis, and C225 M6 Rack Server) are fan modules, which are field-replaceable units responsible for cooling the system.

The highlighted components in the images correspond tocooling fans— these are essential for maintaining optimal thermal conditions within each Cisco UCS server type.Here's a breakdown of what's visible in each:

Cisco UCS 5108 B-Series Blade Server Chassis: The highlighted vertical rectangular components arefan modules, which provide high-efficiency airflow for the densely packed blades.

Cisco UCS X9508 X-Series Modular Server Chassis: The front-facingfan traysare clearly marked, used to cool the modular nodes and shared infrastructure.

Cisco UCS C225 M6 Rack Server: The highlighted components on the side of the motherboard are alsofan modules, directly responsible for cooling the CPU, memory, and other internal components.

These fans arefield-replaceable units (FRUs)and are routinely accessed by technicians during preventive maintenance or fault replacement.

Online Insertion and Removal (OIR)is a feature supported by Cisco ASR routers that allows for the insertion and removal of hardware components, such as line cards and modules, while the router is operating. Thiscapability enables maintenance and upgrades without the need to power down the system, thus minimizing network downtime.​

Key aspects of OIR include:​

Seamless Operation:OIR allows for hardware changes without interrupting the router's operation.​

Preservation of Routing Information:The router maintains all routing information and active sessions during the insertion or removal process.

Administrative Shutdown:While not mandatory, it is recommended to administratively shut down the interfaces associated with the component being removed to ensure a graceful transition.​

This feature is particularly beneficial in high-availability environments where maintaining continuous network service is critical.​

Bundle modesimplifies the installation and operation of Cisco IOS XE Software by using a monolithic image file. In thismode, the switch runs directly from the bundled image, eliminating the need to manage individual software packages. This approach is straightforward and reduces complexity, making it suitable for environments where simplicity is a priority.​

However, it's important to note that:​

Bundle mode may result in slower boot times compared to Install mode.

It does not support the independent installation or upgrade of individual packages.

Thepackages.conffile is not utilized in Bundle mode; it's specific toInstall mode.​

TheSpine-and-Leafarchitecture is the preferredpod-based deployment modelin modern data centers because of itshigh scalability and flexibility. In this topology:

Leaf switchesconnect to servers and act as the access layer.

Spine switchesfunction as the core layer, interconnecting all leaf switches.

This non-blocking, highly redundant model supportspredictable latency, easy horizontal scaling, and load balancing, making it ideal for cloud-scale and virtualized environments.

Top of Rack (ToR)andEnd of Row (EoR)are physical cabling layouts that do not inherently provide the same level of architectural scalability.

Fabric Extender modelsextend switch ports but depend on upstream switches for intelligence, limiting flexibility.

During the boot process of Cisco devices runningNX-OS, pressingCtrl-Cat the right time will interrupt the boot sequence and bring the system to theboot loader or ROMmon mode(commonly referred to as the boot prompt).

This allows a technician to perform low-level operations such as recovering passwords, specifying an alternate boot image, or performing diagnostics.

Other options (Ctrl-X, Ctrl-Z, Ctrl-1) are not used for interrupting the boot process in Cisco NX-OS platforms.

The correct sequence for mounting a Cisco device in a rack is:​

Install mounting brackets: Attach the appropriate rack-mount brackets to the sides of the device using the screws provided. This step prepares the device for secure installation in the rack.​

Mount in rack: Carefully place the device into the rack, aligning the brackets with the rack posts, and secure it using the appropriate rack-mount screws.​

Ground the device: After the device is securely mounted, connect the grounding wire to the chassis grounding point and then to the facility ground. This step ensures safety and compliance with electrical standards.​

This sequence is recommended to ensure both the physical security of the device and the safety of personnel during installation.​

NVRAM → Startup configuration

RAM → Running configuration

ROM → Bootstrap code, POST code, ROM monitor

Flash memory → Cisco IOS software, backup configuration

Each memory type in a Cisco device serves a specific function in the boot process and runtime operation. NVRAM retains configuration across reboots, RAM is volatile and holds active configs, ROM handles initial boot tasks, and flash stores the operating system.

This content is covered thoroughly in"Cisco Equipment and Related Hardware"in the FLDTEC curriculum. Here's the breakdown:

ROM (Read-Only Memory)

Stores bootstrap code, POST (Power-On Self-Test), and ROM Monitor.

These are essential for the device’s initial power-on operations and recovery modes.

NVRAM (Non-Volatile RAM)

Holds thestartup configuration file, which is loaded during the boot process.

Content remains intact after a reboot or power cycle.

RAM (Random Access Memory)

Stores therunning configurationand current operational state of the router or switch.

Also used for routing tables, ARPcache, and packet buffers.

Data is lost when the device is powered off or rebooted.

Flash Memory

Contains theCisco IOS image, system files, and can storebackup configurations.

It is a non-volatile storage, so it retains data after reboots.