Supermicro SSE-G2252, User Manual

Page: 470 / 1401

Chapter 14: Basic Administration Protocols
Connectivity Fault Management
– 477 –
“Default” or “Explicit,” and the MIP creation state machine is invoked
(as defined in IEEE 802.1ag). The default option allows MIPs to be
created for all interconnection points within an MA, regardless of the
domain’s level in the maintenance hierarchy (e.g., customer, provider,
or operator). While the explicit option only generates MIPs within an MA
if its associated domain is not at the bottom of the maintenance
hierarchy. This option is used to hide the structure of network at the
lowest domain level.
The diagnostic functions provided by CFM can be used to detect
connectivity failures between any pair of MEPs in an MA. Using MIPs
allows these failures to be isolated to smaller segments of the network.
Allowing the CFM to generate MIPs exposes more of the network
structure to users at higher domain levels, but can speed up the
process of fault detection and recovery. This trade-off should be
carefully considered when designing a CFM maintenance structure.
Also note that while MEPs are active agents which can initiate
consistency check messages (CCMs), transmit loop back or link trace
messages, and maintain the local CCM database, MIPs, on the other
hand, are passive agents which can only validate received CFM
messages, and respond to loop back and link trace messages.
The MIP creation method defined for an MA (see Configuring
CFM Maintenance Associations) takes precedence over the method
defined on the CFM Domain List.
Configuring Fault Notification
•
A fault alarm can generate an SNMP notification. It is issued when the
MEP fault notification generator state machine detects that the
configured time period (MEP Fault Notify Alarm Time) has passed with
one or more defects indicated, and fault alarms are enabled at or above
the specified priority level (MEP Fault Notify Lowest Priority). The state
machine transmits no further fault alarms until it is reset by the
passage of a configured time period (MEP Fault Notify Reset Time)
without a defect indication. The normal procedure upon receiving a
fault alarm is to inspect the reporting MEP’s managed objects using an
appropriate SNMP software tool, diagnose the fault, correct it, re-
examine the MEP’s managed objects to see whether the MEP fault
notification generator state machine has been reset, and repeat those
steps until the fault is resolved.
•
Only the highest priority defect currently detected is reported in the
fault alarm.
Priority levels include the following options:
Table 14-12: Remote MEP Priority Levels
Priority Level Level Name Description
1 allDef All defects.
2 macRemErrXcon DefMACstatus, DefRemoteCCM, DefErrorCCM, or
DefXconCCM.