Administrator Guide

Authentication, Authorization, and Accounting 233
This authentication method is not implemented by Dell Networking N-Series
switches. Use the Management ACL capability to perform the equivalent
function.
Public key authentication operates as follows:
The administrator first generates a pair of encryption keys, the “public” key
and the “private” key. Messages encrypted with the private key can be
decrypted only by the public key, and vice-versa. The administrator keeps the
private key on his/her local machine, and loads the public key on to the
switch. When the administrator attempts to log into the switch, the protocol
sends a brief message, encrypted with the public key. If the switch can decrypt
the message (and can send back some proof that it has done so) then the
response proves that switch must possess the private key, and user is
authenticated without giving a username/password.
The public key method is implemented in the Dell Networking N-Series
switch as opposed to an external server. If the user does not present a
certificate, it is not considered an error, and authentication will continue with
challenge-response authentication.
Challenge-response authentication works as follows:
The switch sends an arbitrary “challenge” text and prompts for a response.
SSH-2 allows multiple challenges and responses; SSH-1 is restricted to one
challenge/response only. Examples of challenge-response authentication
include BSD Authentication.
Finally, if all other authentication methods fail, SSH prompts the user for a
password.
Access Lines (AAA)
Table 10-3 shows the method lists assigned to the various access lines by
default.
Table 10-3. Default AAA Methods
AAA Service (type) Console Telnet SSH
Authentication
(login)
defaultList networkList networkList
Authentication
(enable)
enableList enableNetList enableNetList