Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 232)

Modified Managed Fabric Name Monitoring mode
Modified Managed Fabric Name Monitoring (M-MFNM) mode prevents connections from the AG VDX
switch to multiple SANs to ensure that all N_Ports in a port group connect to the same FC fabric.
Modified Managed Fabric Name Monitoring (M-MFNM) mode is enabled with LB mode. It queries the
FC fabric name for a default time out value of 120 seconds. If it detects an inconsistency, for example
all the N_Ports within a port group are not physically connected to the same physical or virtual FC
fabric, the following occurs:
• N_Ports are disabled to the fabric with the lower number of connected N_Ports.
• If more than one fabric has the same or the maximum number of ports connected, N_Ports are
disabled to the fabric with the higher "fabric names" (WWN of the Principal Switch). Ports connected
to the lowest "fabric name" stay online.
Consider the following about M-MFNM mode:
• M-MFNM mode is enabled by default when you enable LB mode. You cannot disable it unless you
disable LB mode.
• You can change the default time out value (tov) for fabric name queries using the timeout fnm
value when in ag configuration mode. Refer to Setting and displaying the fabric name monitoring
TOV on page 232.
Setting and displaying the fabric name monitoring TOV
You can set the time out value (TOV) for M-MFNM queries of the fabric name to detect whether all
N_Ports in a port group are physically connected to the same physical or virtual fabric.
Access Gateway and the PG policy must be enabled for this command to succeed.
Use the timeout fnm value command while in ag configuration mode to set time-out value (TOV) for
M-MFNM queries of the fabric name. The valid range is 30 to 3600 seconds. The default value is 120
seconds.
1. Enter the configure terminal command to enter global configuration mode.
switch# configure terminal
2. Enter the rbridge-id id command to enter RBridge ID configuration mode for the specific switch.
switch(config)# rbridge-id 3
3. Enter the ag command to enter Access Gateway configuration mode.
switch(config-rbridge-id-3)# ag
4. Enter the timeout fnm value command to change the time out value for fabric name queries.
switch(config-rbridge-id-3-ag)# timeout fnm 60
5. Enter timeout timeout fnm without a value to display the current M-MFNM timeout value.
switch(config-rbridge-id-3-ag)# timeout fnm
() (60)
N_Port monitoring for unreliable links
N_Port monitoring monitors links between N_Ports on the VDX switch configured in Access Gateway
mode and F_Ports on the connected FC fabric. When links are considered unreliable, the N_Port is
disabled.
Links from all N_Ports are monitored for the number of online and offline static change notifications
(SCNs) that occur during a five-minute period. If the number of SCNs on a link exceeds a set
threshold, the link is considered unreliable, and the port is taken offline. VF_Ports mapped to the
Modified Managed Fabric Name Monitoring mode
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