Brocade BigIron RX Series Configuration Guide - Manual (Page 644)

566 BigIron RX Series Configuration Guide
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MAC Database Update over cluster control protocol
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Clearing port loop detection information
To clear the port loop detection statistics and bring back the specific disabled port to the enabled
state, enter the following command.
BigIron RX(config-if-e1000-1/1)# clear loop-detection
Syntax: clear loop-detection
MAC Database Update over cluster control protocol
Each MCT cluster switch maintains multiple MAC databases (MDBs) corresponding to the cluster
peer. The local MDB consists of the MAC addresses that are learned locally and the remote MDB
consists of the MAC Database Update (MDUP) messages received from the MCT peer. MDUP runs
as an application over the CCP and only the best MAC entry is installed in the Forwarding Decision
Database (FDB).
The MDB resolution algorithm runs on all the MDBs in a given switch to identify which MAC entries
must be installed in FDB. The MDB resolution algorithm works as follows:
• The MAC entries that are learned locally are given the highest priority (or the cost of 0) so they
are always selected as the best MAC entries.
• Each MAC entry is advertised with a cost. Low cost MAC entries are given preference over high
cost MAC entries.
• If a MAC entry moves from a CCEP to a CEP, a MAC move message is sent to the peer and the
peer moves the MAC entry from its CCEPs to the ICLs adjusting the MDBs.
• If the cost of the MAC entries is the same, then the MAC address learned from the lower
RBridge ID is selected as the best MAC entry and is installed in the FDB.
TABLE 108 Output parameters of the show loop-detection command
Field Description
loop detection packets
interval Shows the interval for sending the PLD packets.
loop detection disable
duration Shows the duration for which the port must be disabled after a loop is detected.
port-num Shows the port number for which the loop detection is enabled.
vlan-id Shows the VLAN ID for which the loop detection is enabled.
port-shutdown Shows if the shutdown option is enabled or disabled for a specific port.
shutdown-mode Shows if the shutdown option is enabled on the sending or the receiving port.
disable-count Shows the count of disabled ports.
port Shows the ports that are disabled by the loop detection.
age (minutes) Shows the duration for which the ports are disabled because of loop detection.
disable cause Shows the reason for disabling the ports.