Two MAC addresses for a same IP Primary address

Hi all,

According to the RFC3768, when a multicast VRRP packet is sent, the 
source IP address must be the *Primary IP Address* (section 5.2.1) and 
the source MAC address must be the *Virtual Router MAC Address*.

Moreover, the source MAC address of the the ICMP, TCP, ARP packets 
related to the *IP Address Owner*, must (of course) be the *Virtual 
Router MAC Address*.

Two routers running VRRP should have 2 differents *Primary IP Address*, 
and (of course) the same *IP Address Owner*.

So, if from a host, which is on the same Ethernet network, I send an 
ICMP echo request to:
   - the *Primary IP Address*, which source MAC address should the ICMP 
echo reply use ?
     According to me, it must NOT be the *Virtual Router MAC Address*.
   - the *IP Address Owner*, which source MAC address should the ICMP 
echo reply use ?
     According to me, it must be the *Virtual Router MAC Address*.

So it means that for any packets, when the source IP address is the 
*Primary IP Address*, the source MAC address could be any MAC address of 
the NIC; but when it is a VRRP Multicast packet to 224.0.0.18, the 
source MAC address must be the *Virtual Router MAC Address*.

Conclusion: a *Primary IP Address* can have two MAC addresses !!!, the 
*Virtual Router MAC Address* and the MAC address of the NIC !

It is not logical, so what are we missing ?

According to me:
   -Option1: the section 5.2.1 should specify that the source address 
should be an *IP Address Owner*, instead of the *Primary IP address*.
   -Option2: remove the constraint of the source MAC address of the VRRP 
packet = the *Virtual Router MAC Address*.

I prefer option 2 because it avoids the Ethernet switch from oscillating 
during a transition state.

Regards,
   Vincent

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