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Forum Discussion

jfrizzell_43066's avatar
jfrizzell_43066
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Jan 18, 2012

LTM Connection to Dual Switches

Hello Everyone,   I am hoping that someone can help me understand which connection type is best for F5. We currently have two F5's in an active/failover cluster. In our environment, we are going a...
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mikand_61525's avatar
mikand_61525
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Jan 19, 2012
Techgeeeg: I think hoolio just explained that.

 

 

Instead of relying on if the serial cable functions or not you can use various monitors to decide when the F5 unit should failover or not.

 

 

If you for example have this setup:

 

 

F5_1 -> switch1 -> server1

 

 

F5_2 -> switch2 -> server2

 

 

and then have cables between switch1 - switch2 you could end up with a situation where F5_1 is active but switch1 is broken. In this situation server1 cannot reach F5_1 nor F5_2 while server2 can reach F5_2 but for no good since this unit is still passive (and just ignores the packets).

 

 

If you now use some monitors to trigger the HA instead of the status of the serial cable you would see that F5_1 cant reach server1 nor server2, BUT... F5_2 can at least reach server2. So in this particular case I would prefer that F5_2 becomes active (and sends some snmp trap thats something bad happend since all redundancy is now lost for the moment).