14.14 Hashing Authentication Process

CCNP RS 300-101, Securing Cisco Routers, Uncategorized

The following illustration represents the exchange of keys in a hashed authentication scenario:

  1. The hash is generated based on the key and the specific routing update payload being sent.
  2. The hash is appended to the routing update and sent; the hash is not part of the key, but merely transmitted alongside it.
  3. The receiving router calculates the key based on the hash and the routing update payload. If the keys match, the update is accepted. If it is not, it is silently dropped.

Note that plaintext/simple authentication is still better than no authentication at all.

Note the use of hashing authentication in various routing protocols:

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