[ovs-dev] VLAN tenant network patches

[Mark Michelson]

On 11/09/2018 04:16 PM, Guru Shetty wrote:
> 
> 
> 
>      > Ankur's proposal:
>      > ==============
>      >
>      > Though the complete patches do not exist, Ankur wants to solve
>     the problem
>      > 1 by having a chassis specific MAC. So when packet leaves a
>     hypervisor for
>      > east-west routing, it uses a unique mac. The disadvantage with this
>      > proposal is that the VM (i.e logical port) will see the mac of
>     its first
>      > hop router change continuously which may have some yet to be clearly
>      > defined side-effects (leads to more ARP requests from the VM).
> 
>     I'm having trouble understanding this. Can you elaborate a little bit?
> 
> Consider the following topology
> 
> VM-A (Hypervisor-A) <-----> Switch-A <------>Router <--------> Switch-B 
> <----------------> VM-B (Hypervisor-B)
> 
> When VM-A wants to send traffic to VM-B, it will send a packet with 
> source mac of VM-A and destination mac of Router.
> 
> When VM-B responds to that packet and when VM-A eventually receives that 
> packet, the source mac address of packet will be chassis specific mac of 
> hypervisor-B.  So VM-A sends packet to one mac address, but receives 
> packet from another mac address.
Got it. Now it makes sense.

> 
>     Is this not a problem with the current implementation too?
> 
> 
> With the current implementation, since router mac address is the same 
> across the cluster, it is consistent.
> 
> 
> 
>      >
>