SNMP MIBs and Traps, and RMON Alarm Defaults
B-9
9123-A2-GB20-10 July 2000

Table B-6. linkUp and linkDown Variable-Bindings (1 of 2)

Interface Variable-Bindings Possible Cause

Physical Sublayer
Network
(Supported by the
media-specific DS1
MIB.)
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) or
far-end loss of signal
Out of Frame (OOF)
Alarm Indication Signal
(AIS)
Excessive Error Rate (EER)
Yellow Alarm
Strings:
‘$ifString down.’ No alarms
exist. (e.g., ‘Network T1 down
due to yellow alarm.’)
‘$ifString administratively
shutdown.’ (Due to an
intentional shutdown.)
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
shutdown.’ (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.