Relationship between IKE and IPsec
Figure 103 Relationship between IKE and IPsec
Figure 103
illustrates the relationship between IKE and IPsec:
IKE is an application layer protocol using UDP and functions as the signaling protocol of IPsec.
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IKE negotiates SAs for IPsec and delivers negotiated parameters and generated keys to IPsec.
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IPsec uses the SAs set up through IKE negotiation for encryption and authentication of IP packets.
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Protocols and standards
RFC 2408, Internet Security Association and Key Management Protocol (ISAKMP)
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RFC 2409, The Internet Key Exchange (IKE)
RFC 2412, The OAKLEY Key Determination Protocol
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FIPS compliance
The device supports the FIPS mode that complies with NIST FIPS 140-2 requirements. Support for features,
commands, and parameters might differ in FIPS mode (see "Configuring FIPS") and non-FIPS mode.
IKE configuration task list
Determine the following parameters prior to IKE configuration:
The strength of the algorithms for IKE negotiation (the security protection level), including the
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identity authentication method, encryption algorithm, authentication algorithm, and DH group.
Different algorithms provide different levels of protection. A stronger algorithm means more
resistance to decryption of protected data but requires more resources. Generally, the longer the key,
the stronger the algorithm.
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The pre-shared key or the PKI domain the certificate belongs to. For more information about PKI
configuration, see "Configuring PKI."
To configure IKE:
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