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Mastering Daily CCNA Commands in the Real World
By Sys-Metrics··
Core Commands for Daily Operations
These commands are your go-to for monitoring and managing Cisco devices in real-world networks. They help verify configurations, check connectivity, and ensure smooth operations.
Verification Commands
show version
Description:
Displays system hardware, software version, and uptime.
Use Case:
Check device model and IOS version before upgrades.
show running-config
Description:
Shows the current active configuration.
Use Case:
Verify applied settings, like VLAN assignments, before changes.
show ip interface brief
Description:
Lists interface status, IP addresses, and protocol state.
Use Case:
Quickly check if interfaces are up/down.
show interfaces status
Description:
Shows interface status, speed, duplex, and VLAN.
Use Case:
Identify misconfigured ports.
show mac address-table dynamic
Description:
Lists dynamically learned MAC addresses.
Use Case:
Trace a device’s port by its MAC.
show cdp neighbors detail
Description:
Shows detailed info about connected Cisco devices.
Use Case:
Map network topology.
show lldp neighbors
Description:
Lists non-Cisco neighbors via LLDP.
Use Case:
Verify links to VoIP/IoT gear.
show arp
Description:
Displays ARP table for IP-to-MAC mappings.
Use Case:
Troubleshoot IP conflicts.
ping 8.8.8.8
Description:
Tests connectivity to a public IP.
Use Case:
Confirm internet access.
traceroute 8.8.8.8
Description:
Traces the path to a destination.
Use Case:
Find where packets drop.
copy running-config startup-config
Description:
Saves running configuration to NVRAM.
Use Case:
Persist changes after reboot.
Basic Configuration Commands
enable
Description:
Enters privileged EXEC mode.
configure terminal
Description:
Enters global configuration mode.
hostname SW-ACCESS-01
Description:
Sets device hostname.
no ip domain-lookup
Description:
Disables DNS lookups for typos.
interface range gi1/0/1-24
Description:
Selects multiple interfaces.
description Access Ports
Description:
Adds a description to an interface.
logging synchronous
Description:
Prevents logs from interrupting CLI input.
end
Description:
Exits configuration mode.
write memory
Description:
Alias of copy run start.
Use these commands daily to monitor device health and confirm connectivity.
Configuring VLANs, Access, and Trunk Ports
VLANs segment networks for security and efficiency. Access ports connect devices to a single VLAN, while trunks carry multiple VLANs between switches.
Create and name VLANs for departments.
configure terminal
vlan 10
name Sales
vlan 20
name Support
end
write memory
Configure SVI for inter-VLAN routing on L3 switches.
configure terminal
ip routing
interface vlan 10
ip address 192.168.10.1 255.255.255.0
no shutdown
interface vlan 20
ip address 192.168.20.1 255.255.255.0
no shutdown
end
Description:
SVIs with IP routing enabled.
For Layer 2 switches, use ip default-gateway 192.168.1.1 instead of ip routing.
Safe Factory Reset: Cisco Switches
Resetting a switch to factory defaults is useful for repurposing or troubleshooting, but it wipes all configurations. Always back up first.
Choose the method based on ASA version and needs. Always back up.
write erase
reload
Description:
Clears startup config and reboots.
configure factory-default
reload
Description:
Restores factory defaults with default interfaces.
clear configure all
reload
Description:
Clears all configuration without firmware reset.
Backup via copy running-config tftp: or copy startup-config disk0:.
Quick Troubleshooting Toolkit
Use these to diagnose common issues quickly.
show interfaces counters errors
show spanning-tree inconsistentports
show ip dhcp snooping binding
show port-security interface gi1/0/5
show access-lists
debug ip packet
undebug all
Description:
From Layer1 errors to ACL/Spanning-Tree checks and packet debugging (use with care).
Backup and Restore Configurations
Regular backups protect against data loss; restores allow quick recovery.
