Cannot ping mydomain.local from my other trusted side.
I already cannot remember if it is caused by removal of WINS. Suddenly our two-way trust domains between two trees becomes broken. Well, as I can see from side A to side B seems still fine but from side B to side A is broken. As I can see, I from side B cannot ping side A's DomainA.local while I from side A can ping side B's DomainB.local. Question is, why from side B I cannot ping side A's DomainA.local? Is it a DNS issue ? or WINS issue? or others? Please help.
When you query a machine from a forest that is not in your forest root domain it needs to query the other DNS servers in the other forest to get a reply back.
Another thing you can do is create a secondary zone for Domain A in Domain. You can then do the same for Domain B in Domain A. If you go this route you will need to add "Zone Transfers" for the other forest on each of the Zones you want to present as read only.
If you have all of this in place and it still doesn't work might be a firewall related issue.