Skip to main content

Examining the show commands

Examining the show commands
3.1.4 This page will introduce some show commands. Many of these commands can be used to examine the contents of files in the router and for troubleshooting. In both privileged EXEC and user EXEC modes, the command show ? provides a list of available show commands. The list is considerably longer in privileged EXEC mode than it is in user EXEC mode.


Students should learn the functions of the following commands:

• show interfaces – Displays statistics for all interfaces on a router. To view the statistics for a specific interface, enter the show interfaces command followed by the specific interface slot/port number. This is shown in the following example:

Router#show interfaces serial 0/1

• show controllers serial - Displays information that is specific to the interface hardware. This command must also include the port or slot/port number of the serial interface. For example:

Router#show controllers serial 0/1

• show clock - Shows the time set in the router
• show hosts - Displays a cached list of host names and addresses
• show users - Displays all users who are connected to the router
• show history - Displays a history of commands that have been entered
• show flash - Displays information about flash memory and what IOS files are stored there
• show version - Displays information about the currently loaded software version along with hardware and device information.
• show arp - Displays the ARP table of the router
• show protocols - Displays the global and interface-specific status of any configured Layer 3 protocols
• show startup-config - Displays the saved configuration located in NVRAM
• show running-config - Displays the contents of the currently running configuration file or the configuration for a specific interface, or map class information.

The Lab Activities on this page will teach students how to view router configurations with the show commands. The next page will explain how a serial interface is configured.

Comments

Post a Comment

Popular posts from this blog

Windowing

Windowing 11.1.5 This page will explain how windows are used to transmit data. Data packets must be delivered to the recipient in the same order in which they were transmitted to have a reliable, connection-oriented data transfer. The protocol fails if any data packets are lost, damaged, duplicated, or received in a different order. An easy solution is to have a recipient acknowledge the receipt of each packet before the next packet is sent. If a sender had to wait for an ACK after each packet was sent, throughput would be low. Therefore, most connection-oriented, reliable protocols allow multiple packets to be sent before an ACK is received. The time interval after the sender transmits a data packet and before the sender processes any ACKs is used to transmit more data. The number of data packets the sender can transmit before it receives an ACK is known as the window size, or window. TCP uses expectational ACKs. This means that the ACK number refers to the next packet that is...
Post a Comment
Read more

1.2.2 RIP V2 Features

 1.2.2 RIP V2 Features This page will discuss RIP v2, which is an improved version of RIP v1. Both versions of RIP share the following features: It is a distance vector protocol that uses a hop count metric. It uses hold down timers to prevent routing loops – default is 180 seconds. It uses split horizon to prevent routing loops. It uses 16 hops as a metric for infinite distance. RIP v2 provides prefix routing, which allows it to send out subnet mask information with the route update. Therefore, RIP v2 supports the use of classless routing in which different subnets within the same network can use different subnet masks, as in VLSM. RIP v2 provides for authentication in its updates. A set of keys can be used on an interface as an authentication check. RIP v2 allows for a choice of the type of authentication to be used in RIP v2 packets. The choice can be either clear text or Message-Digest 5 (MD5) encryption. Clear text is the default. MD5 can be used t...
Post a Comment
Read more

OSI layers / Peer-to-peer communications / TCP/IP model

OSI layers 2.3.4 This page discusses the seven layers of the OSI model. The OSI reference model is a framework that is used to understand how information travels throughout a network. The OSI reference model explains how packets travel through the various layers to another device on a network, even if the sender and destination have different types of network media. In the OSI reference model, there are seven numbered layers, each of which illustrates a particular network function. - Dividing the network into seven layers provides the following advantages: • It breaks network communication into smaller, more manageable parts. • It standardizes network components to allow multiple vendor development and support. • It allows different types of network hardware and software to communicate with each other. • It prevents changes in one layer from affecting other layers. • It divides network communication into smaller parts to make learning it easier to understand. In the foll...
Post a Comment
Read more