Midterm Switches and Routers CH 6-8 Set 2

What is stored in RAM on a router/switch?

Running-configuration, routing tables, ARP cache, MAC address table, active IOS, packet buffers. Volatile - lost on reboot.

What is stored in NVRAM?

Startup-configuration. Non-volatile - survives reboots.

What is stored in Flash memory?

Cisco IOS image(s). Non-volatile - survives reboots.

What's the difference between running-config and startup-config?

Running-config is active in RAM (current settings). Startup-config is saved in NVRAM (loads on boot).

What command makes the running-config permanent?

copy running-config startup-config (or write memory or wr)

What command brings an interface up/makes it active?

no shutdown (from interface configuration mode)

What does "administratively down" mean?

The interface was manually disabled with the shutdown command.

What is setup mode and why does a router enter it?

Interactive configuration dialog. Router enters when there's no startup-config in NVRAM.

What is the test sequence called when you turn on a router?

POST (Power-On Self-Test)

What is the router boot sequence?

1) POST from ROM 2) Bootstrap from ROM 3) IOS loads from Flash to RAM 4) Startup-config loads from NVRAM to RAM

What does "Serial1 is down, line protocol is down" mean?

Layer 1 (physical) problem. Cable issue, no clock rate, hardware failure, or interface shutdown.

What does "Serial1 is up, line protocol is up" mean?

Interface fully functional. Physical connection good, data link layer working properly.

What does show interface tell you?

Layer 1 status (up/down), Layer 2 info (line protocol, encapsulation, MAC), bandwidth, errors, collisions.

What does show ip interface tell you?

Layer 3 information - IP address, subnet mask, whether IP is configured and operational.

What does show version display?

IOS version/filename, configuration register value, uptime, memory info, interfaces on device.

What does show flash tell you?

IOS images stored in flash, file sizes, available space.

What does show memory display?

RAM usage (processor and I/O memory).

What does show buffers show?

Buffer pool statistics and memory allocation for packet buffers.

What does the configuration register do and what's the default value?

Controls boot behavior. Default: 0x2102

What configuration register value bypasses startup-config?

0x2142 (used for password recovery)

What's the command sequence to backup running-config to TFTP?

copy running-config tftp (source first, destination second)

What's the command to restore IOS from TFTP to Flash?

copy tftp flash

What's the command to backup startup-config to TFTP?

copy startup-config tftp

What's the command to restore startup-config from TFTP?

copy tftp startup-config

What are the requirements for using TFTP with copy commands?

1) IP connectivity between router and TFTP server 2) TFTP server software running 3) Correct TFTP server IP address 4) Sufficient space on server 5) Proper file permissions

What's the difference between ping/trace from a router vs from a PC?

Router CLI offers extended ping/trace with more options (source interface selection, detailed settings). PC has basic ping/trace with limited options.

What's the difference between in-band and out-of-band management?

In-band: Management through production network (Telnet/SSH) - requires working network. Out-of-band: Management through console port with direct cable - works even if network is down.

What does CLI stand for?

Command Line Interface

What must be done when using a laptop connected to a router's Ethernet port to restore IOS or config?

1) Configure laptop IP in same subnet as router interface 2) Ensure router interface is no shutdown 3) Setup TFTP server on laptop 4) Verify connectivity with ping 5) Use copy tftp flash or copy tftp startup-config