We sometimes run multiple versions of the same VM on the network, virtualized using KVM on Red Hat Linux. The Guest OS is almost always Windows. I change the MAC address in the config and disable the network link temporarily, then boot up the cloned VM and change the hostname before it can register itself in DNS as the same name as the other existing VM. Once it has a unique name, I enable the network link and reboot.
The problem is, one of the VMs has a long name like LongNameVM1500000, so I changed it to LongNameVM1500001 but the NETBIOS name of both machines is LongNameVM150000 because NetBIOS has a 16 character limit. What are the ramifications of having duplicate NetBIOS names on a LAN? We use DNS for name resolution, I just want to know if there is any real danger in this. The cloned VM is in a workgroup, not bound to the domain and both OS's are XP SP 3.