SNMP MIBs and Traps, and RMON Alarm Defaults
B-9
9783-A2-GB20-00 July 2000

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.)
HifIndex (RFC 1573)
HifAdminStatus
(RFC 1573)
HifOperStatus (RFC 1573)
HdevLastTrapString
(devHealthAndStatus.-
mib)
HlinkDown – One or more alarm
conditions are active on the
interface.
Alarm conditions include:
Loss of Signal (LOS)
Loss of Frame (LOF)
Loss of Link (LOL)
Loss of Signal Quality
LPR Events

Sample strings:

‘Network DSL down due to
LOS, LOF, and LOL.’
‘Network DSL down due to
Loss of Signal Quality.’
HlinkUp – No alarms on the
interface.
String:
‘$ifString up.’
Synchronous
Data Port
(Supported by the
media-specific
RS232-like MIB.)
HifIndex (RFC 1573)
HifAdminStatus
(RFC 1573)
HifOperStatus (RFC 1573)
HdevLastTrapString
(devHealthAndStatus.-
mib)
HlinkDown – One or more alarm
conditions are active on the
port.
Alarm conditions include:
DTR off1
RTS off2
‘’ – Not DTR or RTS, but
link is down.
String:
‘$ifString $alarmString down.’
(e.g., ‘Sync Data Port S01P1
DTR and RTS down.’)
‘$ifString administratively shut
down.’ (Due to an intentional
shutdown.)
HlinkUp – No alarms on the
port.
String:
‘$ifString up.’
1The DTR alarm condition will only generate a linkUp/linkDown trap if the DTE
supports the DTR lead state.
2The RTS alarm condition will only generate a linkUp/linkDown trap if the DTE
supports the RTS lead state.