You can bind only to network interfaces available on the machine where MySQL is running. There's no way for PC A to access the network interface on PC B, so consequently the MySQL server refuses to start.
Assume your PC has 3 network interfaces:
- 127.0.0.1 (local host or local loop)
- 192.168.0.50 (network card/cable)
- 192.168.0.70 (network card/wireless)
Normally, the MySQL server will listen on all three interfaces. This is the default, but if it makes you happy :-) you could set it explicitly, with --bind-address='0.0.0.0'.
If you want MySQL to listen only on the cable interface you would set --bind-address='192.168.0.50'.
for more information on bind-address.
Stefan Hinz, MySQL Documentation, Berlin, Germany