Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 1056)

1000 Brocade 6910 Ethernet Access Switch Configuration Guide
53-1002651-02
43
Connectivity Fault Management
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”
on page 1003) 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 178 Remote MEP Priority Levels
Priority Level Level Name Description
1 allDef All defects.
2 macRemErrXcon DefMACstatus, DefRemoteCCM, DefErrorCCM, or DefXconCCM.
3 remErrXcon DefErrorCCM, DefXconCCM or DefRemoteCCM.
4 errXcon DefErrorCCM or DefXconCCM.
5 xcon DefXconCCM
6 noXcon No defects DefXconCCM or lower are to be reported.
TABLE 179 MEP Defect Descriptions
Defect Description
DefMACstatus Either some remote MEP is reporting its Interface Status TLV as not isUp, or all remote MEPs
are reporting a Port Status TLV that contains some value other than psUp.
DefRemoteCCM The MEP is not receiving valid CCMs from at least one of the remote MEPs.