Is it secure for a firewall to allow NetBIOS connections from the internal network to the DMZ?
- If not secure, what are the risks?
- If secure, what is the FUD about and what are the counterarguments?
No. Typically you don't want your servers where they trust any other systems because that means they could compromise the DMZ server and tunnel using that trusted relationship. That means no domains, etc. Therefore, NetBIOS is not exactly useful since there are no trusts. Also, by the very nature of a system being in a DMZ the recommendation is:
This goes for services, users, protocols, etc. Therefore, NetBIOS usually gets struck pretty quick.