Networks

It can ping the FQDN but not the NETBIOS name, try the below out.

Add the child domain to the dns suffixes:
Go to Control Panel -> Network -> LAN -> Right click on your LAN conection and select "Properties" -> Select "TCP/IP" -> Select "Properties" -> Click "Advanced" -> Select "DNS" tab.
Tick "Append these DNS suffixes (in order)"
Add your normal domain fqdn as first entry
Add your child domain(s) fqdn as secondary and so on entry

i.e.:
root.local
child1.root.local
child2.root.local

DNS will now search for a unqualified name in your domain and if not found in your child domain(s).

Keep us informed as to your progress if you require further assistance.

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