User's Manual

MDS 05-6302A01, Rev. B MDS Mercury 16E Technical Manual 43
• Limited USM User Table Manipulation. The SNMP Agent
starts with five default accounts. New accounts can be added
(SNMPv3 adds new accounts by cloning existing ones), but
they will be volatile (will not survive a power-cycle). New
views cannot be configured on the SNMP Agent. Views are
inherited for new accounts from the account that was cloned.
The SNMP Agent uses one password pair (Authentication/Pri-
vacy) for all accounts. This means that when the passwords
change for one user, they change for all users.
SNMPV3 Accounts The following default accounts are available for the SNMP Agent:
enc_mdsadmin-Read/write account using Authentication and Encryption.
auth_mdsadmin-Read/write account using Authentication.
enc_mdsviewer-Read only account using Authentication and Encryption.
auth_mdsviewer-Read only account using Authentication.
def_mdsviewer-Read only account with no Authentication or Encryption.
Context Names The following Context Names are used (refer to RFC2574 for full
details):
• Admin accounts is context_a
• Viewer accounts is context_v.
All accounts share the same default passwords:
• Authentication default password is MDSAuthPwd
• Privacy default password is MDSPrivPwd
Passwords can be changed either locally (via the console) or from an
SNMP Manager, depending on how the Agent is configured. If
passwords are configured and managed locally, they are non-volatile
and will survive a power-cycle. If passwords are configured from an
SNMP manager, they will be reset to whatever has been stored for local
management on power-cycle.
This behavior was chosen based on RFC specifications. The SNMP
Manager and Agent do not exchange passwords, but actually exchange
keys based on passwords. If the Manager changes the Agent's password,
the Agent does not know the new password. The Agent only knows the
new key. In this case, only the Manager knows the new password. This
could cause problems if the Manager loses the password. If that occurs,
the Agent becomes unmanageable. Resetting the Agent's passwords
(and therefore keys) to what is stored in flash memory upon power-cycle
prevents the serious problem of losing the Agent's passwords.