IP address is probably the best way to go unless the computers are not using a static address. If they use DHCP they will keep the same address and usually everyone is happy but in the case where power goes out or the PC is offline beyond its lease you may be assigned a new IP address. If you use a full address make sure you are not getting that address through a mapped drive where it looks like it should work but does not. Also mapped drive might be different. I also amuse that all the connections have been established for each location. The links for one location will not be the same as those at another location.

Make sure the rights are set up correctly too. Access to a shared folder does not mean you have rights to the folders they are in so the link might be stopped due to improper rights.

Sometimes the surest way to to manual input the path for each location and see if you can make a link.