Suppose you have two interfaces in the host belonging to the same subnet connected to a normal L2/L3 switch port which has a single vlan with interface IP 10.0.0.1.
nxge0 (10.0.0.201) (00:14:4f:fb:d7:af) --> ex0/1 nxge1 (10.0.0.202) (00:14:4f:fb:dbe:91) --> ex0/2
The routing table in the host says that for all packets whose destination is 10.0.0.0/24, use nxge0 interface first and then nxge1. So all packets to 10.0.0.0/24 will go out from nxge0 interface. Say someone pings from the switch to 10.0.0.202. First the switch will learn the mac address of 10.0.0.202 from ARP reply. Then it will construct a packet using destination mac as 00:14:4f:fb:dbe:91 and ICMP Echo Request. Packet arrives on the host and the host sends ICMP Echo Reply. Now the funny part is the packet will be having the source mac address (00:14:4f:fb:d7:af) since it is sent out from nxge0 interface.
On the switch side, we see that the ping was successful. Can the above scenario be a problem for any protocol? Is my understanding correct. Thanks for your help.