Brocade Network OS NETCONF Operations Guide v4.1.1 - Manual (Page 267)

Network OS NETCONF Operations Guide 235
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Chapter
18
Administering Edge-Loop Detection
In this chapter
• Edge-loop detection overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
• Configuring edge-loop detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
• Edge-loop detection troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Edge-loop detection overview
This chapter provides procedures for configuring edge-loop detection using the NETCONF interface.
Refer to the Network OS Administrator’s Guide for a conceptual overview of edge-loop detection
(ELD) and how ELD detects loops.
Configuring edge-loop detection
Edge-loop detection (ELD) requires configuration at the global level and at the interface level. For
global level configuration, you must set the number of PDUs that the Brocade VCS Fabric cluster
receives on any port before determining that a loop exists. This value is the pdu-rx-limit. You must
also set the interval between sending PDUs, known as the hello-interval. The combination of
pdu-rx-limit and hello-interval timer determines the time it takes for ELD to detect and break a loop.
At the interface level, you must enable ELD on each port on which you want it to run and set the
port priority. You should also specify a VLAN on which ELD is enabled.
Set the pdu-rx-limit to a different number on each Brocade VCS Fabric cluster so that only one
Brocade VCS Fabric cluster disables a port. We recommend setting this value in the increment of
two to prevent race conditions which might disable ports on two Brocade VCS Fabric clusters that
are incrementally only one apart.
Set the hello-interval to the same value on all Brocade VCS Fabric clusters for which ELD is
configured, otherwise the results of edge-loop detection become unpredictable.
Optionally, set the shutdown-time to configure ports to be re-enabled after a specified period of
time (range 0 minutes to 24 hours). A typical use for this feature is in environments in which
reconfiguration is common, such as in a typical lab environment. Typical use is to allow the default
value of zero, which does not allow ports to be re-enabled automatically.
NOTE
Any change to the shutdown-time takes effect only for the ports that are disabled by ELD after the
configuration change. Any ports that were already disabled by ELD before the shutdown-time change
continue to follow the old shutdown-time value. These ports start to follow the new shutdown-time
after the currently running timer expires and ELD still detects the loop and shuts down the port
again.