Information About Implementing Keychain Management; Lifetime Of A Key; How To Implement Keychain Management - Cisco IOS XR Configuration Manual

Information About Implementing Keychain Management

Information About Implementing Keychain Management
The keychain by itself has no relevance; therefore, it must be used by an application that needs to
communicate by using the keys (for authentication) with its peers. The keychain provides a secure
mechanism to handle the keys and rollover based on the lifetime. Border Gateway Protocol (BGP), Open
Shortest Path First (OSPF), and Intermediate System-to-Intermediate System (IS-IS) use the keychain
to implement a hitless key rollover for authentication. For information about BGP, OSPF, and IS-IS
keychain configurations, see Cisco IOS XR Routing Configuration Guide.
BGP uses TCP authentication, which enables the authentication option and sends the Message
Authentication Code (MAC) based on the cryptographic algorithm configured for the keychain.
To implement keychain management, you must understand the following concepts:
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Lifetime of a Key

If you are using keys as the security method, you must specify the lifetime for the keys and change the
keys on a regular basis when they expire. To maintain stability, each party must be able to store and use
more than one key for an application at the same time. A keychain is a sequence of keys that are
collectively managed for authenticating the same peer, peer group, or both.
Keychain management groups a sequence of keys together under a keychain and associates each key in
the keychain with a lifetime.
Any key that is configured without a lifetime is considered invalid; therefore, the key is rejected during
Note
configuration.
The lifetime of a key is defined by the following options:
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Each key definition within the keychain must specify a time interval for which that key is activated; for
example, lifetime. Then, during a given key's lifetime, routing update packets are sent with this activated
key. Keys cannot be used during time periods for which they are not activated. Therefore, we recommend
that for a given keychain, key activation times overlap to avoid any period of time for which no key is
activated. If a time period occurs during which no key is activated, neighbor authentication cannot occur;
therefore, routing updates can fail.
Multiple keychains can be specified.

How to Implement Keychain Management

This section contains the following procedures:
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Cisco IOS XR System Security Configuration Guide
SC-76
Lifetime of a Key, page SC-76
Start-time—Specifies the absolute time.
End-time—Specifies the absolute time that is relative to the start-time or infinite time.
Configuring a Keychain, page SC-77
Configuring a Tolerance Specification to Accept Keys, page SC-78
Configuring a Key Identifier for the Keychain, page SC-79
Configuring the Text for the Key String, page SC-81
Implementing Keychain Management on Cisco IOS XR Software
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