Questions Flashcards
How to check interface configuration?
Show ip interface brief
How to show interface MAC address ?
Show interface gig0/0
How to show dynamically learned MAC address ?
Show mac address -table dynamic
How to show routing table?
Show ip route
How to configure ip on an interface?
R1 (config) #interface GigabitEthernet 0/1
R1 (config-if)#ip address 10.10.20.1 255.255.255.0
R1 (config-if) #no shutdown
How to configure a static route?
R1 (config) #ip route 10.10.30.0 255.255.255.0 10.10.10.2
How to configure a router as a DNS srerver ?
R2 (config) #ip domain-lookup
R2 (config) #ip name-server 10.10.10.10
What shows arp?
The arp command shows the Address Resolution Protocol (ARP) table on your computer. This table maps IP addresses to MAC addresses on your local network.
What the Columns Mean:
• Internet Address: The IP address of the device on the local network.
• Physical Address: The MAC address (hardware address) of the device.
• Type:
• dynamic means it was learned via ARP.
• static means it was manually set.
This is mainly useful for troubleshooting network issues or checking which devices your computer has recently communicated with on your local LAN.
How to configure a routers or switch hostname?
Configure Router 2 with the hostname ‘R2’
Router (config) #hostname R2
R2 (config) #
Configure Switch 1 with the hostname ‘SW1’
Switch (config) #hostname SW1
SW1 (config) #
How to add a management ip on a switch?
SW1 (config) #interface vlan1
SW1 (config-if)#ip address 10.10.10.10 255.255.255.0
SW1 (config-if) #no shutdown
How to add ip default getaway?
SW1 (config) #ip default-gateway 10.10.10.2
Why add a description note?
We add descriptions on a switch (especially in network configurations) mainly for clarity and documentation. Here’s why it’s useful:
1. Easier management – Descriptions help network administrators understand the purpose of a port (e.g., “Connected to HR printer” or “Uplink to Core Switch”) without needing to trace cables.
2. Troubleshooting – When something goes wrong, having descriptions makes it quicker to identify where a device is connected and what its function is.
3. Collaboration – In environments where multiple people manage the network, descriptions provide context for others, reducing confusion and miscommunication.
4. Auditing and compliance – Descriptions can support inventory control and compliance requirements by showing exactly what is connected where.
5. Future-proofing – If someone else (or future-you) looks at the config months or years later, the descriptions can save a lot of guesswork.
That “description” is just a note — it doesn’t affect traffic, but it shows up in the running config and when someone does commands like:
show running-config
show interfaces description
How to show IOS version on a running switch?
SW1#show version
Cisco IOS Software, C2960 Software (C2960-LANBASE-M) , Version 12.2 (25) FX, RELEASE SOFTWARE (fc1)
How to change speed and duplex on an interface?
R2 (config) #interface FastEthernet 0/0
R2 (config-if)#speed 100
R2 (config-if)#duplex full
What is cdp?
Cisco Discovery Protocol
Here’s a quick overview:
• What it is: CDP is a Layer 2 protocol developed by Cisco.
• Purpose: It allows Cisco devices (like switches, routers, IP phones) to discover information about directly connected Cisco devices, even if Layer 3 (IP) connectivity is not configured.
• What it shows: Device ID, IP address, platform, capabilities, interface info, etc.
• Common command:
• To view CDP neighbors: show cdp neighbors
• To view detailed info: show cdp neighbors detail
Example use case: You’re troubleshooting a network, and you want to know what device is connected to a specific port on your switch — CDP can help you identify it easily.
How to prevent an interface from discovering information via cdp?
SW1 (config) #interface FastEthernet 0/1
SW1 (config-if) #no cdp enable
How to factory reset a router and reboot?
write erase
#reboot
Setting a password on router?
R1 (config) #enable secret Flackbox1
R1 (config)# do copy run start
Destination filename [startup-configl?
Building configuration…
[OK]
R1 (config) #
How to configure a router to boot into the rommon prompt?
R1 (config) #config-register 0x2120
R1 (config) #end
R1#reload
Proceed with reload? (confirm]
In rommon mode, configure the router to ignore the startup-config when booting up, and reload the router.
rommon 1 › confreg 0x2142
rommon 2 > reset
How to remove enable secret password?
R1 (config) #no enable secret
After reset a router how to reload normally
NR1 (config) #config-register 0x2102
R1 (config) #end
R1#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
How to backup a running configuration to flash on a router
R1#copy run flash
Destination filename [running-config]? Backup-1
Building configuration…
[OK]
Rl#show flash
System flash directory:
File Length Name/status
5 728 Backup-1
3 33591768 2900-universalk9-mz. SPA. 151-4. M4. bin
2 28282 sigdef-category.xml
1 227537 sigdef-default.xml
[33848315 bytes used, 221895685 available, 255744000 totall
249856K bytes of processor board System flash (Read/Write)
Backup a routers startup configuration to the TFTP server.
R1#copy start tftp
Address or name of remote host []? 10.10.10.10
Destination filename [R1-confg]? Backup-2
Writing startup-config….!!
[OK - 698 bytes]
698 bytes copied in 3.007 secs (242 bytes/sec)
