Command Passive-Interface Use This command disables RIP for a specific interface on the router. Syntax Router(config-router)#passive-interface <interface> Example First, here are the route tables for all routers with no passive-interface default. R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#router rip R2(config-router)#no passive-interface default R1 route …

Command Version 2 Use Switches router rip version to version 2. The benefits of rip version 2 are: -Increased security -More efficient (uses multicast instead of broadcast) -Supports classless addresses Syntax Router(config-router)#version 2 Example Here is the version 1 debug for R3. R3(config-router)#do debug ip rip RIP protocol …

Filtering Output Use In the Cisco IOS, there are several different ways to control the output so that you get only the information that you want. Syntax <any command> | <include or exclude or section> <text string or regular expression>< | ><text string or regular expression> Options <include> …

Command Show DHCP Lease Use This command shows DHCP lease information for interfaces that are configured with DHCP on the router. Syntax Router#show dhcp lease Example In the below example we configure R1’s Fa0/0 to use DHCP. R1(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 IP Protocols Use This command displays a summary of configured routing protocol information. It is useful for quickly verifying how routing protocols are configured. It is mainly used for RIP, since there aren’t very many other troubleshooting commands available. Syntax Router#show ip protocols Example In the …

Command Show IP Route Connected Use Allows you to see just the directly connected routes installed in the routing table. Syntax Router#show ip route ospf Example Here’s an example of the show ip route connected command. First, here’s the entire routing table of R2, outputted from the show ip route command. R2(config-if)#do sh …

Command Show IP Route RIP Use Allows you to see the RIP routes installed in the routing table. Syntax Router#show ip route rip Example The following example demonstrates the output of this command. First, show ip route is executed on R2 to display the entire routing table. R2(config-if)#do sh ip route Codes: …

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. R2#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. R1(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 …