B. SNMP MIBs, Traps, and RMON Alarm Defaults
B-8 December 2002 9700-A2-GB20-20
Trap: linkUp and linkDown
These traps are supported on the following interfaces:
Physical sublayer interfaces: Network and synchronous data ports
Logical link layer interfaces: Frame relay
The linkUp and linkDown variable-bindings are in Table B-6, linkUp and linkDown
Variable-Bindings.
Physical and logical sublayers are represented by the entry in the MIB II Interfaces
Table. It is supported by a combination of the Frame Relay Extension MIB and
either the Frame Relay Services MIB or the Frame Relay DTEs MIB.
Table B-5. linkUp and linkDown Traps
Trap What It Indicates
linkDown A failure on one of the communication interfaces has occurred.
linkUp One of the failed communication interfaces is up and operational.
Table B-6. linkUp and linkDown Variable-Bindings (1 of 3)
Interface Variable-Bindings Possible Cause
Physical Sublayer
Network
(Supported by an
entry in the MIB-II
Interfaces Table.)
ifIndex (RFC 1573)
ifAdminStatus (RFC1573)
ifOperStatus (RFC1573)
devLastTrapString
(devHealthAndStatus.mib)
linkDown – One or more alarm
conditions are active on the
interface. Alarm conditions
include:
– Loss of Signal (LOS)
– Signal-to-Noise (S/N) Net
Margin Threshold exceeded
Strings:
‘$ifString down.’
(e.g., ‘Network DSL down due
to LOS.’)
‘$ifString administratively shut
down.’ (Due to an intentional
shutdown.)
linkUp – No alarms on the
interface.
String
:
‘$ifStringup.’