3.3.n [ii] Key-chain
Key chains consist of two mandatory and two optional components. The necessary components are key number and key string. Optionally it also include an accept-lifetime and a send-lifetime parameter.
Key chain configuration steps:
● First you need to configure key chain in global configuration mode.
● Under key chain you need to configure key number. Key number must be match on both side of router and should be active. If multiple key numbers are configured on a router , the router will select the lowest key ID number for outbound authentication however will accept any matching valid keys in the keychain upon receipt
● Once you configure key number you need to issue authentication string
Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 2880-2881). . Kindle Edition.