B. SNMP MIBs and Traps, and RMON Alarm Defaults
9128-A2-GB20-80 September 2002 B-11
Table B-6. linkUp and linkDown Variable-Bindings (1 of 2) Interface Variable-Bindings Possible Cause
Physical Sublaye r
T1 Network,
DSX-1,
PRI
(Supported by the
media-specific DS1
MIB.)
ifIndex (RFC 1573)
ifAdminStatus (RFC
1573)
ifOperStatus (RFC 1573)
devLastTrapString
(devHealthAndStatus.-
mib)
linkDown – 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.)
linkUp – No alarms on the
interface.
String:
‘$ifString up.’
Synchronous Data
Port
(Supported by the
media-specific
RS232-like MIB.)
ifIndex (RFC 1573)
ifAdminStatus
(RFC 1573)
ifOperStatus (RFC 1573)
devLastTrapString
(devHealthAndStatus.-
mib)
linkDown – One or more alarm
conditions are active on the
port.
Alarm conditions include:
–DTR off1
–RTS off2
–‘ ’ – Not DTR or RTS, but
link is down.
String:
‘$ifString $alarmString down.’
(e.g., ‘Sync Data Port S01P1
DTR and RTS down.’)
‘$ifString administratively
shutdown.’ (Due to an
intentional shutdown.)
linkUp – 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 w ill only generate a linkUp /linkDown trap if th e DTE
supports the RTS lead state.
3If the LMI Protocol is not configured, a linkUp/linkDown trap is based solely upon
whether the interface is enabled or disabled.