Is only SNMP RO access enough for all 3 levels (Basic, Intermediate and Advanced) of operation in MARS? Since using SNMP RO, all required information should be accessible (configuration resolving, NAT and PAT resolving, topology discovery, attack paths discovery, etc.).
"The SNMP access type is not required to enable the SMPO RO strings. In fact, no access type is required to support SNMP RO. SNMP RO uses a shared, read-only community string; it does not require a read-write community string as does the SNMP access type."
Important part is "it does not require a read-write community string as does the SNMP access type.". Does this mean that for SNMP access type, SNMP RW is required?
Further, on the same link it sais:
"Step 1 In the Login field, enter the username of the administrative account to use when accessing the reporting device.; Step 2 In the Password field, enter the password associated with the username specified in the Login field.; Step 3 If this device supports an enable mode, enter that password in the Enable Password field."
What has username, password and enable password to do with SNMP v1 (as MARS supports SNMP v1 only)
Each access method (telnet,ssh) has a particular role. You need to match your particular needs with the access method For example you cannot use SNMP to retrive the ASA configuration file. Have a look at this table, it lists the access-method required for each particular device category:
SNMP read write is only required if you want to perform mitigation on layer 2 switches.
As a best practice try to use SSH as much as possible.