MLAG ports with a Untagged VLAN - Loop

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Just would like to understand if you have an un-tagged vlan for example vlan default on your mlag ports on both switches will this create a loop."Yes vlan default is also on the ISC port between the switchs"

Would this be like joying to access ports together?

I understand when it comes to tagged vlans within MLAG, but i was just worried about unttaged vlan's. In a normal case you would not have an unattged vlan but i am asking what if.

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Ian Worms

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Posted 3 years ago

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Prashanth KG, Employee

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Hi Ian,

MLAG would avoid the loop in the VLANs by constantly checkpointing the FDB entries between the peers. ISC blocking mechanism is independent of whether the VLAN is tagged or untagged. 
So, ideally there should not be a loop if you have a VLAN untagged in the MLAG ports. 
Hope this helps!