|Here is a quote from another forum. Let us know if it helps.|
What is not working? Still cannot ping ABC.local from DEF.com? If so, then you next step is to find out why is the DNS zone of ABC.local not being able to replicate to the DEF.com DNS server.
On your DEF.com DNS server, see if you have the ABC.local zone under the "Forward Lookup Zones". If not, right click on the Forward Lookup Zones and click on "New Zone...". Go through the GUY and for simplicty and consistency of this thread, select "Secondary zone"(as suggested above Stub zone) can be used. But since I don't believe you have such a huge DNS database, it generally a very small database even with a couple of thousand of entries. So a Secondary zone would replicate exactly what you have in your primary zone). Typing the zone name of ABC.local click on Next then enter the IP of the DNS server that hosting your ABC.local DNS which assuming it's the DC of ABC.local. After entering the IP just click on next next and you are done. Right click on the secondary zone of "ABC.local" you have just created and click on "transfer from master". If you don't get the transfer, then go the DNS server of ABC.local and right click on the primary zone(or ADIZ zone) and select Properties. Click on the tab "Zone Transfer". Under the "Only to the following servers, make sure the IP of the DNS server, assuming it your DC of DEF.COM is added. Then on your DEF.COM's DNS server, do the transfer from Master again. If you still can't transfer and replicate the ABC.Local DNS to DEF.com, then it is most likely block by firewall. If you have no problem replicating the DNS zone of ABC.Local to the DNS server of DEF.COm, then you should be able to ping the name of the ABC.local.
How do you know when a politician is lying? His mouth is moving.