CCSP Self-Study: Securing Cisco IOS Networks (SECUR)

H

hash.

The result of transforming, or hashing, a string of characters into a usually shorter, fixed-length value or key that represents the original string.

Hashed Message Authentication Codes (HMAC).

A mechanism for message authentication using cryptographic hash functions. HMAC can be used with any iterative cryptographic hash function, for example, MD5 or SHA-1, in combination with a secret shared key. The cryptographic strength of HMAC depends on the properties of the underlying hash function.

headend.

Endpoint of a broadband network. All stations transmit toward the headend, which then transmits toward the destination stations.

hold-down routes.

Routes used to make a remote VPN connection appear to be active even when there is no current tunnel ...