For each topology: successful ping replies from 192.168.1.2, .1.3 and .1.4; ideally 0% packet loss after ARP resolution.
PDU: PC0 -> PC3 | ICMP | Successful
Bus/HUB: frame signals repeated to other ports (non-destinations discard).
Star/SWITCH: learns MAC addresses; known unicast sent only to destination port.
Ring/SWITCHES: one redundant link may be orange/blocking because of STP.
Hybrid: switch -> hub -> switch forwarding works within same LAN.
