baker@VITAM6.UUCP (Fred Baker) (11/30/89)
RFC 1098 SNMP April 1989
single sub-tree of the object type name space.
An element of the set { READ-ONLY, READ-WRITE } is called an SNMP
access mode.
A pairing of a SNMP access mode with a SNMP MIB view is called an
SNMP community profile. A SNMP community profile represents
specified access privileges to variables in a specified MIB view. For
every variable in the MIB view in a given SNMP community profile,
access to that variable is represented by the profile according to
the following conventions:
(1) if said variable is defined in the MIB with "Access:" of
"none," it is unavailable as an operand for any operator;
(2) if said variable is defined in the MIB with "Access:" of
"read-write" or "write-only" and the access mode of the
given profile is READ-WRITE, that variable is available
as an operand for the get, set, and trap operations;
(3) otherwise, the variable is available as an operand for
the get and trap operations.
(4) In those cases where a "write-only" variable is an
operand used for the get or trap operations, the value
given for the variable is implementation-specific.
A pairing of a SNMP community with a SNMP community profile is called
a SNMP access policy. An access policy represents a specified
community profile afforded by the SNMP agent of a specified SNMP
community to other members of that community. All administrative
relationships among SNMP application entities are architecturally
defined in terms of SNMP access policies.
For every SNMP access policy, if the network element on which the
SNMP agent for the specified SNMP community resides is not that to
which the MIB view for the specified profile pertains, then that
policy is called a SNMP proxy access policy. The SNMP agent
associated with a proxy access policy is called a SNMP proxy agent.
While careless definition of proxy access policies can result in
management loops, prudent definition of proxy policies is useful in
at least two ways:
(1) It permits the monitoring and control of network elements
which are otherwise not addressable using the management
protocol and the transport protocol. That is, a proxy
agent may provide a protocol conversion function allowing
a management station to apply a consistent management
Case, Fedor, Schoffstall, & Davin [Page 8]
Fred Baker
baker@vitalink.com