Switching The Nm-Specific Interface Index Format; Configuration Guidelines; Configuration Procedure - HP 6125G Configuration Manual

Switching the NM-specific interface index format

A network management (NM)-specific ifindex identifies an interface and is provided by the SNMP
managed device to the NMS. A network management-specific ifindex takes one of the following two
formats:
16-bit NM-specific ifindex—The system dynamically assigns 16-bit NM-specific ifindex values to
•
uniquely identify its interfaces. The 16-bit NM-specific ifindex value starts from 1 and increments by
1.
32-bit NM-specific ifindex—A 32-bit NM-specific ifindex value comprises an Offset, Interface Type,
•
Slot ID, and Chassis ID, as shown in
Figure 23 32-bit NM-specific ifindex
0
Offset—This field is 16 bits long and distinguishes different interfaces of the same type on the
same interface card.
Interface type—This field is 7 bits long and contains the enumerated value specific to the
interface type. It supports up to 128 different interface types and supports more than 80
interface types at present.
Slot ID—This field is 5 bits long and contains the number of the physical slot that holds the
interface.
Chassis ID—This field is 4 bits long. For a distributed device in IRF mode, this field indicates the
IRF member ID of the device that provides the interface. For other types of device, this field has
no meanings and the value is 0.

Configuration guidelines

Use the 32-bit NM-specific ifindex format if the NMS requires the format to get information such as
•
the slot that contains a specific interface. If the network protocol operating on the NMS does not
support 32-bit NM-specific ifindex values, make sure NM-specific ifindex values on the device are
16-bit. By default, the device adopts the 16-bit NM-specific ifindex format.
• An NM-specific ifindex format change invalidates the NM-specific ifindex dependent settings, and
these settings cannot become valid until you switch the format back. To use these settings in the new
format, you must re-configure them. For example, if an RMON alarm group or private alarm group
has alarm variables in the format OID/variable-name.NM-specific-ifindex, you must reconfigure
these variables after an NM-specific ifindex format change.

Configuration procedure

To switch the NM-specific ifindex format:
Step
1. Enter system view.
2. Switch the format of an
NM-specific ifindex from
16-bit to 32-bit.
Figure
Offset
Command
system-view
snmp-agent ifmib long-ifindex
enable
23.
15
Interface Type
57
22 27
Slot ID Chassis ID
Remarks
N/A
Optional.
By default, an NM-specific ifindex
is in 16-bit format.
31