If you plan to have both types of RSA authentication methods in your IKE policies, you may prefer to generate special-usage keys. However, you could specify more than one IKE policy and have RSA signatures specified in one policy and RSA-encrypted nonces in another policy. A CA is used only with IKE policies specifying RSA signatures, not with IKE policies specifying RSA-encrypted nonces. One pair will be used with any Internet Key Exchange IKE policy that specifies RSA signatures as the authentication method, and the other pair will be used with any IKE policy that specifies RSA encrypted keys as the authentication method. Special-Usage Keys If you generate special-usage keys, two pairs of RSA keys will be generated. When you generate RSA key pairs, you will be prompted to select either special-usage keys or general-purpose keys. There are two mutually exclusive types of RSA key pairs: special-usage keys and general-purpose keys. Note If the configuration is not saved to NVRAM, the generated keys are lost on the next reload of the router. Note Secure Shell SSH may generate an additional RSA key pair if you generate a key pair on a router having no RSA keys. This situation is not true when you generate only a named key pair.
You will be unable to complete the crypto key generate rsa command without a hostname and IP domain name. Note Before issuing this command, ensure that your router has a hostname and IP domain name configured with the hostname and ip domain-name commands. If your router already has RSA keys when you issue this command, you will be warned and prompted to replace the existing keys with new keys. RSA keys are generated in pairs-one public RSA key and one private RSA key. Use this command to generate RSA key pairs for your Cisco device such as a router. For more information about the latest Cisco cryptographic recommendations, see the NGE white paper. Usage Guidelines Note Security threats, as well as the cryptographic technologies to help protect against them, are constantly changing. The range value for the modulus keyword value is extended from 360 to 2048 bits to 360 to 4096 bits. The signature, encryption and on keywords and devicename : argument were added. Command Modes Global configuration Command History Release Modification 11. Command Default RSA key pairs do not exist. Keys created on a USB token must be 2048 bits or less. The name of the device is followed by a colon. The name of the storage device is followed by a colon. The maximum for private key operations prior to these releases was 2048 bits. Note Effective with Cisco IOS XE Release 2.
The range of a CA key modulus is from 350 to 4096 bits. The recommended modulus for a CA key is 2048 bits. By default, the modulus of a certification authority CA key is 1024 bits. If a key label is not specified, the fully qualified domain name FQDN of the router is used. If you do not assign a label, the key pair is automatically labeled. You can specify other modulus sizes with the modulus keyword. The key for 750 users is added to the 5520. When you try to copy and paste your config again on to the screen you will be unable to activate more than 3 vlans. You will then need to apply the licence to the device. Cisco ASA firewall licensing used to be pretty simple. ※ Download: ?dl&keyword=cisco+asa+key+generator&source= Cisco ASA SSH, Don’t Forget To Generate A Key