[ovs-dev] [PATCH] vswitchd: Explain why mirroring to a VLAN can cause network problems.

Justin Pettit jpettit at nicira.com
Thu Sep 3 19:53:15 UTC 2009

Good job on tracking down this issue.  I just have a few minor comments:

On Sep 2, 2009, at 5:16 PM, Ben Pfaff wrote:

> +.IP
> +Mirroring to a VLAN can disrupt a network that contains unmanaged

What about leading into it more with "Please note that mirroring to a  

> +This
> +reflected packet causes the physical switch to learn that the end
> +host's MAC address is on port 2.

I think it may be clearer if you indicate that this is actually  
replacing a valid entry as opposed to just simple learning.  Something  
like:  "This reflected packet causes the unmanaged physical switch to  
replace the correct MAC entry which pointed to port 1 with an entry  
that points to port 2."

> +If
> +mirroring to a VLAN must be used in this scenario, then the physical
> +switch must be replaced by one that learns Ethernet addresses on a
> +per-VLAN basis.

What about switch "If mirroring to a VLAN must be used in this  
scenario" to "If mirroring to a VLAN is desired in this scenario".   
This way it sounds less like the user is doing something inappropriate.


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