> # Implementing IPsec Without CAs and Digital Certificates

> Without a CA and digital certificates, enabling IPsec services (such as encryption) between two Cisco MDS switches requires that each switch has the key of the other switch (such as an RSA public key or a shared key). You must manually specify either the RSA public keys or preshared keys on each switch in the fabric using IPsec services. Also, each new device added to the fabric will require manual configuration of the other switches in the fabric to support secure communication. Each switch uses the key of the other switch to authenticate the identity of the other switch; this authentication always occurs when IPsec traffic is exchanged between the two switches.

> If you have multiple Cisco MDS switches in a mesh topology and want to exchange IPsec traffic passing among all of those switches, you must first configure shared keys or RSA public keys among all of those switches.

> Every time a new switch is added to the IPsec network, you must configure keys between the new switch and each of the existing switches.

> Consequently, the more devices that require IPsec services, the more involved the key administration becomes. This approach does not scale well for larger, more complex encrypting networks.

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