Category: CCNA Study Guide
Command Show IP OSPF Neighbor Use Displays the router’s ospf adjacencies. Syntax Router#show ip ospf neighbor Example Here are the ospf adjacencies for R2. CopyR2#show ip ospf neighborNeighbor ID Pri State Dead Time Address Interface 133.133.133.133 1 FULL/DR 00:00:35 10.2.2.3 FastEthernet1/0 111.111.111.111 1 FULL/DR 00:00:33 10.1.1.1 FastEthernet0/0
Command Show IP EIGRP Topology Use This command shows EIGRP topology information on the router. This information includes the advertised and feasible distance for all paths as well as the successors. This is especially useful when calculating variance. Syntax Router#show ip eigrp topology Example In the below example …
Command Show DHCP Server Use This command shows information about known DHCP servers that have communicated with the router. Syntax Router#show dhcp server Example In the below example we configure R1’s Fa0/0 to use DHCP. CopyR1(config)#int fa0/0 R1(config-if)#ip address dhcp R1(config-if)# *Mar 1 01:39:29.295: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor …
Command Show IP DHCP Binding Use This command lists the addresses that the DHCP service on a router has assigned. Syntax Router#show ip dhcp binding Example In the below example we configure R1’s Fa0/0 to use DHCP. CopyR1(config)#int fa0/0 R1(config-if)#ip address dhcp R1(config-if)# *Mar 1 01:39:29.295: %DUAL-5-NBRCHANGE: IP-EIGRP(0) …
Command Show Sessions Use This command displays information about the telnet sessions that the router has established. Syntax Router#show sessions Example In this example, we use show sessions on R1 after we telnet to R2 and suspend the session. CopyR1(config)#do telnet 10.1.1.2 Trying 10.1.1.2 … Open User Access Verification Password: …
Command Show Interfaces Use This command displays detailed layer 1 information about interfaces on a device, including tracking errors. It is useful for quickly checking the status of the device. Syntax Router#show interfaces OR Router#show interfaces <interface> Example In the below example we use show interfaces to quickly see layer 1 …
Command Show Frame-Relay PVC Use This command displays any PVC information the router has learned about. Syntax Router#show frame-relay pvc <dlci> Example In this example, we use show frame-relay mapping to verify that R4 has learned about the other links via inverse-arp. We also verify that we can ping. CopyR4(config)#do …
Command Show Controller Use This command displays very detailed controller and interface information. Most of the time, you will only use this command to see if a serial link is a DCE or a DTE. Syntax Router#show controller <interface> Example In this example, we use show controller s1/1 | …
Command Show Startup-Config Use Shows the saved startup configuration on a router. Syntax Router#show startup-config Example In this example, the show start command is executed to display the startup config on R1. CopyR1#show start Building configuration… Current configuration : 1106 bytes ! version 12.4 service timestamps debug datetime msec service …
Command Show CDP Neighbors Detail Use This command shows detailed information about the Cisco devices that are directly connected to your current device, including IP addresses. CDP is a Cisco proprietary protocol and will only detect Cisco products, although there are some vendors that do work with it. Additionally, …
