> # Implementing IPsec with CAs and Digital Certificates

> With CA and digital certificates, you do not have to configure keys between all the encrypting switches. Instead, you individually enroll each participating switch with the CA, requesting a certificate for the switch. When this has been accomplished, each participating switch can dynamically authenticate all the other participating switches. When two devices want to communicate, they exchange certificates and digitally sign data to authenticate each other. When a new device is added to the network, you simply enroll that device with a CA, and none of the other devices needs modification. When the new device attempts an IPsec connection, certificates are automatically exchanged and the device can be authenticated.

> To add a new IPsec switch to the network, you need only configure that new switch to request a certificate from the CA, instead of making multiple key configurations with all the other existing IPsec switches.

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