Hello, Linda
Thanks for your comments. Agree, that's why the nest paragraph next to your 
comment is "Therefore the VNIC association notifies will be sent to the 
attached NVE. When the NVE receives the VNIC association notify, it shall 
verify the received info with the VNIC address association list of the VN 
context. If the same VNIC address association is found, the misconfiguration 
can be detected. "

Have a nice day
Zu Qiang

From: Linda Dunbar [mailto:[email protected]]
Sent: Tuesday, September 17, 2013 10:41 AM
To: Zu Qiang; Larry Kreeger (kreeger)
Cc: [email protected]; [email protected]
Subject: RE: Error notification [draft-ietf-nvo3-nve-nva-cp-req-00]

Zu Qiang,

My comments inserted below:


If the two TSs have been located in the different hypervisors under the same 
NVE, the hypervisors may not be able to detect this error.
[Linda] Under this circumstance, the NVE will receive data frames with same SA 
address from different links. Then NVE can notify the error.

Therefore the VNIC association notifies will be sent to the attached NVE. When 
the NVE receives the VNIC association notify, it shall verify the received info 
with the VNIC address association list of the VN context. If the same VNIC 
address association is found, the misconfiguration can be detected.
If the two TSs have been located in the different hypervisors under the 
different NVEs, the hypervisors may not be able to detect this error. Therefore 
the VNIC association notifies will be sent to the attached NVEs.

-                          In this case, the attached NVE will receive the VNIC 
association notify from the hypervisor, which the VNIC address association list 
of the VN will be configured. At the same time an inner-outer address mapping 
configuration message will be received from the NVA which the inner address 
will be the same as the address received in the VNIC association notify, which 
means the misconfiguration can be detected.

-                          The not attached NVE will receive two instances of 
the inner-outer address mapping, which the inner address are same and the outer 
address are different, which means the misconfiguration can be  detected.
In VM migration case, it is possible to have the VNIC disassociation at the old 
location after the VNIC association at the new location. A timer based solution 
may be needed to avoid triggering the error handling too quick.
As discussed above, the misconfiguration of the TS address can be detected. And 
the NVE(s) shall notify the NVA when the error is detected. Therefore, a 
protocol is needed to allow the NVE to report the detected address 
misconfiguration to the NVA.


Have a nice day
Zu Qiang
______________________________________________________________________________________________________________________


  *   4.4: is the timer solution good enough for the case of address 
misconfiguration? How the NVE knows there is an address misconfiguration or it 
is VM mobility?

LK> The timer is just a way to implement the optimization of not notifying the 
NVA when a VM moves and we don't have a pre-associate to tell us directly.  It 
is related to VNIC migration, and not related to address configuration.  I'm 
not sure what you are referring to.
[Zu Qiang] there may be the case that two VMs under different NVEs are 
configured with the same address by mistake. In this case, the NVA may receive  
the VM connections notifications from both NVEs. The notification may not be 
received at same time. How should the NVA knows this is a VM mobility or a 
misconfiguration? Do we need a procedure to cover that case?

LK2> I see.  If a duplicate address is configured by mistake, then there is no 
good way to know which VM has the correct address.  I'm not sure if we can 
guarantee that a migration event will always be communicated to the NVE, nor 
whether a disconnect will aways come before a connect, so it may be difficult 
to detect the difference between a new VM coming up and a migration.  We plan 
to merge in some content from draft-kompella-nvo3-server2nve-02, so maybe we 
can address this issue as part of that.
[Zu Qiang] I think this is an issue which shall be covered in NVO3. I can 
provide some text on this if it is ok for you.

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