should i enable Netbios over tcp/ip?
Yes you can, this option is used by the programs in the Samba suite to determine what naming services to use and in what order to resolve host names to IP addresses. Its main purpose to is to control how netbios name resolution is performed. The option takes a space separated string of name resolution options.
The options are: "lmhosts", "host", "wins" and "bcast". They cause names to be resolved as follows:
: Lookup an IP address in the Samba lmhosts file. If the line in lmhosts has no name type attached to the NetBIOS name (see the lmhosts(5) for details) then any name type matches for lookup.
: Do a standard host name to IP address resolution, using the system /etc/hosts , NIS, or DNS lookups. This method of name resolution is operating system depended for instance on IRIX or Solaris this may be controlled by the /etc/nsswitch.conf file. Note that this method is used only if the NetBIOS name type being queried is the 0x20 (server) name type or 0x1c (domain controllers). The latter case is only useful for active directory domains and results in a DNS query for the SRV RR entry matching _ldap._tcp.domain.
: Query a name with the IP address listed in the wins server parameter. If no WINS server has been specified this method will be ignored.
: Do a broadcast on each of the known local interfaces listed in the interfaces parameter. This is the least reliable of the name resolution methods as it depends on the target host being on a locally connected subnet.
I recommend using NETBIOS over TCIP and opening the TCIP ports for NETBIOS and CLOSING the UDP ports at the firewalls.
Ports 137, 138, 139 and 443.
Depending on the clients and windows configuration you may need UDP 139 and UPD 443.
These are all internal (local sub net) never out to the internet.
Remember to open ports for input on clients with firewalls.
The gateway or router must open ports for input from the local net also (the second nic or the subnet ip set)
For more information see 'man smb.conf'