Category: CCNA Study Guide
Command PPP Authentication CHAP Use This command enables CHAP authentication on the PPP link. Syntax Router(config-if)#ppp authentication chap Example In this example, we will configure R1’s S1/1 inteface to authenticate R3 using CHAP. CopyR1(config)#int s1/1 R1(config-if)#encapsulation ppp R1(config-if)#ppp authentication chap R1(config-if)# *Mar 2 01:42:38.237: %LINEPROTO-5-UPDOWN: Line protocol on …
Command IP Split-horizon Use Split Horizon protects against routing loops by not accepting routes on the same interface that a router sends out the updates out. This normally has to be turned off in hub and spoke topologies to ensure full reachability. Syntax Router(config-if)#no ip split-horizon Example In …
Command IP RIP Receive Use This command is used tell RIP what version to receive its updates in for a specified interface. Updates can be sent in Version 1, Version 2, or both. It is useful if you have a legacy host that runs RIP but only supports …
Command IP OSPF Dead-Interval Use Sets the OSPF dead interval for the interface. Syntax Router(config-if)#ip ospf dead-interval <seconds> Example In this example, the dead-interval is configured R1’s int fa0/0. Here’s the ospf interface information before the changes. CopyR1(config-if)#do show ip ospf interface fa0/0 FastEthernet0/0 is up, line protocol is …
Command IP OSPF Network point-to-point Use This command manually sets the OSPF network type to point-to-point. This is the default for serial links. The point-to-point network type does not have a DR election. Note: Point-to-point can only have a single adjaceny over a link. Syntax Router(config-if)#ip ospf network …
Command IP OSPF Priority Use This command is used to manually set the DR election priority of a link. By default all links are equal with a priority of 1. Higher is better. A priority of 0 is used to prevent a router from ever becoming DR which …
Command IP MTU Use This command changes the MTU of a link if required. It is mostly used for DSL or similar setups. Syntax Router(config-if)#ip mtu <68-1500> Example In this example, we will lower the MTU on R1’s Fa0/0 to 1492. CopyR1(config-if)#int fa0/0 R1(config-if)#ip mtu 1492 R1(config-if)#do sh …
Command IP Bandwidth-Percent Use This command is used to change how much bandwidth the EIGRP routing process can use on a link. By default EIGRP can use up to 40% of the bandwidth. This is for EIGRP operational traffic, such as queries or hellos. Syntax Router(config-if)#ip bandwidth-percent eigrp …
Command Encapsulation Dot1Q Use Allows you to use a router interface as a trunk port to a switch. This is also known as “Router on a stick” because the switch uses the router to route between VLANs. Syntax Router(config-subif)#encapsulation dot1Q <vlan> <native> Option <native> Sets the vlan on …
Command Description Use This command is used to set a description on an interface. Syntax CopyRouter(config-if)#description <line> Example In this example, we will set a description on R1’s Fa0/0 interface CopyR1(config)#int fa0/0 R1(config-if)#description "LAN link to R2"
