Cisco Systems 78-11741-02 manual Configuring Eigrp Protocol-Independent Parameters, IPC-266

Configuring EIGRP

EIGRP Configuration Task List

	Command	Purpose
Step 3
	Router(config-if)#ip authentication key-chain	Enables authentication of EIGRP packets.
	eigrp autonomous-system key-chain
Step 4
	Router(config-if)# exit	Exits to global configuration mode.
	Router(config)#
Step 5
	Router(config)# key chain name-of-chain	Identifies a key chain. (Match the name configured in
		Step 1.)
Step 6
	Router(config-keychain)# key number	In keychain configuration mode, identifies the key
		number.
Step 7
	Router(config-keychain-key)# key-stringtext	In keychain key configuration mode, identifies the key
		string.
Step 8
	Router(config-keychain-key)# accept-lifetime	Optionally specifies the time period during which the key
	start-time {infinite end-time duration	can be received.
	seconds}
Step 9
	Router(config-keychain-key)# send-lifetime	Optionally specifies the time period during which the key
	start-time {infinite end-time duration	can be sent.
	seconds}

Each key has its own key identifier (specified with the key number key chain configuration command), which is stored locally. The combination of the key identifier and the interface associated with the message uniquely identifies the authentication algorithm and MD5 authentication key in use.

You can configure multiple keys with lifetimes. Only one authentication packet is sent, regardless of how many valid keys exist. The software examines the key numbers in order from lowest to highest, and uses the first valid key it encounters. Note that the router needs to know the time. Refer to the Network Time Protocol (NTP) and calendar commands in the “Performing Basic System Management” chapter of the Cisco IOS Configuration Fundamentals Configuration Guide.

For an example of route authentication, see the section “Route Authentication Example” at the end of this chapter.

Configuring EIGRP Protocol-Independent Parameters

EIGRP works with AppleTalk, IP, and IPX. The bulk of this chapter describes EIGRP. However, this section describes EIGRP features that work for AppleTalk, IP, and IPX. To configure such protocol-independent parameters, perform one or more of the tasks in the following sections:

•Adjusting the Interval Between Hello Packets and the Hold Time

•Disabling Split Horizon

For more protocol-independent features that work with EIGRP, see the chapter “Configuring IP Routing Protocol-Independent Features” in this document.

Adjusting the Interval Between Hello Packets and the Hold Time

You can adjust the interval between hello packets and the hold time.

Routing devices periodically send hello packets to each other to dynamically learn of other routers on their directly attached networks. This information is used to discover neighbors and to learn when neighbors become unreachable or inoperative.

Cisco IOS IP Configuration Guide

IPC-266