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Multiple clusters with Automatic MAC Magic configuration on same network maintain their default MAC Magic value Technical Level
Symptoms
  • Multiple Gateway Clusters with Automatic MAC Magic configuration are connected to the same network segment.
  • The Cluster Control Protocol (CCP) is operating in Unicast mode.
  • When a new Gateway Cluster is introduced on the same network segment, it does not change its MAC Magic value automatically.
  • The two cluster have the same magic MAC, example:

    First Cluster:
    
    [Expert@CL1:0]# cphaprob -a if
     
    CCP mode: Automatic
    Required interfaces: 3
    Required secured interfaces: 1
    
    eth0       Non-Monitored         non sync(non secured)
    eth1       UP                    non sync(non secured), unicast
    eth2       UP                    sync(secured), unicast
    eth3       UP                    non sync(non secured), unicast
    
    Virtual cluster interfaces: 2
    
    eth1            10.10.1.1
    eth3            173.26.172.1
    
    [Expert@GW1C1:0]# cphaprob mmagic
    
    Configuration mode:  Automatic
    Configuration phase: Stable
    
    MAC magic:         1
    MAC forward magic: 254
    
    Used MAC magic values: None.
     
    Second Cluster:
    
    [Expert@GW1C2:0]# cphaprob -a if
     
    CCP mode: Automatic
    Required interfaces: 3
    Required secured interfaces: 1
    
    eth0       Non-Monitored         non sync(non secured)
    eth1       UP                    non sync(non secured), unicast
    eth2       UP                    sync(secured), unicast
    eth3       UP                    non sync(non secured), unicast
    
    Virtual cluster interfaces: 2
    
    eth1            10.10.10.1
    eth3            173.26.172.11
    
    [Expert@CL2:0]# cphaprob mmagic
    
    Configuration mode:  Automatic
    Configuration phase: Stable
     
    MAC magic:         1
    MAC forward magic: 254
    
    Used MAC magic values: None.
     
Cause

When creating/introducing a new cluster to network with an existing cluster already in unicast mode, the switch port might flap.  Under normal operation with unicast mode, the clusters do not see CCP packets from each other, which results in both clusters using default MAC Magic.  The duplicate/conflicting MAC Magic causes the switch port to flap.


Solution
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