Course Content
Networking Today
0/7
Network Components
Network Representations and Topologies
Common Types of Networks
Internet Connections
Reliable Networks
Network Security Basic
Network Trends
Basic Switch and End Device Configuration
0/7
Cisco IOS Access
Cisco IOS Navigation
Cisco IOS Command Structure
Basic Cisco Device Configuration
Save Cisco IOS Configurations
Ports and Addresses
Configure IP Addressing
Protocols and Models
0/7
The Rules in Network Communications
Protocols
Protocol Suites
Standards Organizations
Reference Models
Data Encapsulation
Data Access
Physical Layer
0/6
Purpose of the Physical Layer
Physical Layer Characteristics
Copper Cabling
UTP Cabling
Fiber-Optic Cabling
Wireless Media
Data Link Layer
0/3
Purpose of the Data Link Layer
WAN and LAN topologies
Data Link Frame
Ethernet Switching
0/4
Ethernet Frames
Ethernet MAC Address
The MAC Address Table
Switch Speeds and Forwarding Methods
Network Layer
0/5
Network Layer Characteristics
IPv4 Packet
IPv6 Packet
How a Host Routes
Router Routing Tables
Number Systems
0/2
Binary Number System
Hexadecimal Number System
Address Resolution
Explain how ARP and ND enable communication on a network
0/3
MAC and IP
ARP
Neighbor Discovery
Basic Router Configuration
0/3
Configure Initial Router Settings
Configure Interfaces
Configure the Default Gateway
IPv4 Addressing
0/7
IPv4 Address Structure
IPv4 Unicast, Broadcast, and Multicast
Types of IPv4 Addresses
Network Segmentation
Subnet an IPv4 Network
VLSM
Structured Design
IPv6 Addressing
0/8
IPv4 Issues
IPv6 Address Representation
IPv6 Address Types
GUA and LLA Static Configuration
Dynamic Addressing for IPv6 GUAs
Dynamic Addressing for IPv6 LLAs
IPv6 Multicast Addresses
Subnet an IPv6 Network
ICMP
0/2
ICMP Messages
Ping and Traceroute Testing
Transport Layer
0/7
Transportation of Data
TCP Overview
UDP Overview
Port Numbers
TCP Communication Process
Reliability and Flow Control
UDP Communication
Application Layer
0/7
Application, Presentation, and Session
Peer-to-Peer
Web Protocols
Email Protocols
Dynamic Host Configuration Protocol (DHCP)
Domain Name Service
File Sharing Services
Network Security Fundamentals
0/4
Security Threats and Vulnerabilities
Network Attacks
Network Attack Mitigation
Device Security
Build a Small Network
0/7
Devices in a Small Network
Small Network Applications and Protocols
Scale to Larger Networks
Verify Connectivity
Host and IOS Commands
Troubleshooting Methodologies
Troubleshooting Scenarios
Basic Device Configuration
0/5
Configure a Switch with Initial Settings
Configure Switch Ports
Secure Remote Access
Basic Router Configuration
Verify Directly Connected Networks
CCNA: Switching, Routing, and Wireless Essentials
The second course in the CCNA curriculum focuses on switching technologies and router operations that support small-to-medium business networks and includes wireless local area networks (WLAN) and security concepts.
0/15
Switching Concepts
VLANs
Inter-VLAN Routing
STP
Etherchannel
DHCPv4
SLAAC and DHCPv6 Concepts
FHRP Concepts
LAN Security Concepts
Switch Security Configuration
WLAN Concepts
WLAN Configuration
Routing Concepts
IP Static Routing
Troubleshoot Static and Default Routes
CCNA: Enterprise Networking, Security, and Automation
The third CCNA course describes the architectures and considerations related to designing, securing, operating, and troubleshooting enterprise networks – including wide area network (WAN) technologies & quality of service (QoS) mechanisms for secure remote access, along with software-defined networking, virtualization, & automation concepts supporting network digitization.
0/14
Single-Area OSPFv2 Concepts
Single-Area OSPFv2 Configuration
Network Security Concepts
ACLs Concepts
ACLS for IPv4 Configuration
NAT for IPv4
WAN Concepts
VPN and IPsec Concepts
QoS Concepts
Network Management
Network Design
Network Troubleshooting
Network Virtualization
Network Automation
CCNA Course
About Lesson

Host and IOS Commands

Use host and IOS commands to acquire information about the devices in a network.

IP Configuration on a Windows Host

In Windows 10, you can access the IP address details from the Network and Sharing Center to quickly view the four important settings: address, mask, router, and DNS. Or you can issue the ipconfig command at the command line of a Windows computer.

  • Use the ipconfig /all command to view the MAC address, as well as a number of details regarding the Layer 3 addressing of the device.
  • If a host is configured as a DHCP client, the IP address configuration can be renewed using the ipconfig /release and ipconfig /renew commands.
  • The DNS Client service on Windows PCs also optimizes the performance of DNS name resolution by storing previously resolved names in memory. The ipconfig /displaydns command displays all of the cached DNS entries on a Windows computer system.

IP Configuration on a Linux Host

  • Verifying IP settings using the GUI on a Linux machine will differ depending on the Linux distribution and desktop interface.
  • On the command line, use the ifconfig command to display the status of the currently active interfaces and their IP configuration.
  • The Linux ip address command is used to display addresses and their properties. It can also be used to add or delete IP addresses.

Note: The output displayed may vary depending on the Linux distribution.

IP Configuration on a macOS Host

  • In the GUI of a Mac host, open Network Preferences > Advanced to get the IP addressing information.
  • The ifconfig command can also be used to verify the interface IP configuration at the command line.
  • Other useful macOS commands to verify the host IP settings include networksetup -listallnetworkservices and the networksetup -getinfo <network service>.

The arp Command

The arp command is executed from the Windows, Linux, or Mac command prompt. The command lists all devices currently in the ARP cache of the host.

  • The arp -a command displays the known IP address and MAC address binding. The ARP cache only displays information from devices that have been recently accessed.
  • To ensure that the ARP cache is populated, ping a device so that it will have an entry in the ARP table.
  • The cache can be cleared by using the netsh interface ip delete arpcache command in the event the network administrator wants to repopulate the cache with updated information.

Note: You may need administrator access on the host to be able to use the netsh interface ip delete arpcache command.

Common show Commands Revisited

Command Description
show running-config Verifies the current configuration and settings
show interfaces Verifies the interface status and displays any error messages
show ip interface Verifies the Layer 3 information of an interface
show arp Verifies the list of known hosts on the local Ethernet LANs
show ip route Verifies the Layer 3 routing information
show protocols Verifies which protocols are operational
show version Verifies the memory, interfaces, and licenses of the device

The show cdp neighbors Command

  • CDP provides the following information about each CDP neighbor device:
    • Device identifiers – The configured host name of a switch, router, or other device
    • Address list – Up to one network layer address for each protocol supported
    • Port identifier – The name of the local and remote port in the form of an ASCII character string, such as FastEthernet 0/0
    • Capabilities list – Whether a specific device is a Layer 2 switch or a Layer 3 switch
    • Platform – The hardware platform of the device.
  • The show cdp neighbors detail command reveals the IP address of a neighboring device.

The show ip interface brief Command

  • One of the most frequently used commands is the show ip interface brief command.
  • This command provides a more abbreviated output than the show ip interface command.
  • It provides a summary of the key information for all the network interfaces on a router.

   

Other related topics

 

Topic Title Topic Objective
Devices in a Small Network Identify the devices used in a small network.
Small Network Applications and Protocols Identify the protocols and applications used in a small network.
Scale to Larger Networks Explain how a small network serves as the basis of larger networks.
Verify Connectivity Use the output of the ping and tracert commands to verify connectivity and establish relative network performance.
Host and IOS Commands Use host and IOS commands to acquire information about the devices in a network.
Troubleshooting Methodologies Describe common network troubleshooting methodologies.
Troubleshooting Scenarios Troubleshoot issues with devices in the network.

 

Other useful information

 

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