Can a partly configured vlan on an extreme summit switch cause network disruption in a live environment

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ExtremeXOS (x460G2-48p-G4
Firmware: 16.1.2.14
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Fred Adjei

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Posted 2 years ago

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Henrique, Employee

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Hi Fred,

If you create a vlan, add ports to it and then create a physical loop without the right protection/configuration, that could cause network disruption.

Have you faced any network issue after creating a vlan? If so, could you please provide us more details?
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Fred Adjei

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Write a reply Thanks  Henrique.   I was configuring vlan on the switch at the time. the commands entered are;
create vlan <name>
configure vlan <name><vlan id>
configure vlan <name> add ports <ports> tagged?? .... not sure whether I got this far before we started experiencing network issues. End-user PCs loosing connections to the network randomly.  Lost communication to the second core.
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Henrique, Employee

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Hi Fred, 

I believe this network impact was caused by a loop. Maybe right after adding the ports to a vlan.

Depending on your network topology you have some loop prevention mechanisms.

You can use STP/EAPS/ERPS for ring topologies which will also keep one link blocked to prevent looping and at same time provide redundancy.

Another option would be run ELRP or even track MAC.Moves to try to find which device is causing the loop. 
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Fred Adjei

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Hi Henrique,

Many thanks for the explanation and giving me pointers for the future.
(Edited)
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Ryan Mathews, Alum

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Thanks for joining the Hub Fred.  We're glad to have you in our purple Community!