HP SNMP/XL User's Guide (36922-90036)

18 Chapter1
Introduction to HP SNMP/XL
Concepts and Definitions
Access Information Once SNMP acknowledges the SNMP entity as a
member of a community, the managed node determines the level of
access that is allowed. Access modes can be: Read-only, Read-Write,
Write-only, or Not accessible.
MIB Groups
The MIB is divided into groups allowing the SNMP manager to poll the
SNMP agents for information. MIB I divides the objects into the
following eight groups:
1. System Group. Contains generic configuration information.
2. Interface Group. Contains generic information on the entities at
the interface layer.
3. Address Translation Group (AT). Contains address resolution
information.
4. Internet Protocol Group (IP). Contains information used to keep
track of the IP layer on the managed node.
5. Internet Control Message Protocol Group (ICMP). Contains 26
counters, counting how many times this message type was generated
by the local IP entity and how many times this message type was
received by the local IP entity. It also counts the total number of
ICMP messages received, sent, received in error, or not sent due to
error.
6. Transmission Control Protocol Group (TCP). Contains
information used to keep track of the application entities using TCP.
7. User Datagram Protocol Group (UDP). Contains information
used to keep track of the application entities using UDP.
8. Exterior Gateway Protocol Group (EGP). Contains information
about the EGP, if it is implemented.
MIB II adds the following two groups to the list.
1. Transmission Group. Holds a place for media-specific MIBS. They
start out in the experimental branch and may eventually be placed
in the Internet-standard MIB.
2. SNMP Group. Contains information used to keep track of SNMP
application entities. It provides statistical information about the
SNMP protocol entity and tracks the amount of management traffic
that a device responds to.