why the MAC address for s5700 are the same?

HI,
The MAC addresses of the working at Layer 2 interfaces are the same for Switchs and Routers.

@user_3445655 hi,
yes, it's designed like that.
for the layer 2 switching, it's not necessary to provide a mac address for the traffic because the traffic is not towarding to the switch itself.
If you capture the layer 2 swtiching packets, you'll find that the source mac address and the destination mac address both are not the switch mac address.
But for layer 3 routing, the source host and destination are in different network, the packets should be forwarded to the router or gateway, then the packets will be checked by the router, and forwarded out.

For switch as a layer 2 , no need for every port to have a specific mac address as it is just forwarding the traffic by knowing what is the destination mac in the frame and then forward it to the port in the mac address table ... Swicth don't change in the mac address in the frame .
For router in the layer 3 , when the packet travel from router to another router , there is encapsulation and encapsulation process happen and during it the source and destination IP during the trip don't change but in every hop the mac address of destination and source (for the specific hop ) will change and that's why we need mac for every interface in the router .