We have 5 child domains with differnet sites(fully ip routed)
Site Design :-
Root DC - NSROOT.net
Child dc- Apac.nsroot.net,nam.nsroot.net,Jpn.nsroot.net,aus.nsroot.net and eur.nsroot.net.
My replication topology is HUb and spoke.
where Newyork(Nsroot.net) site is hub and rest of the site are spokes.
Each and every site is having a global catalog serves.
We have ADC for apac and nam domains in different location .Even ADC is also GC server.
Dns Part : -
In root domain I had created delegation for all my child domains.
Every child domains is having separate DNS servers, name resolution between all sites looks good.
We have 2 exchange servers, one in NAM and another one in APAC.
I had created a universal distribution group named gbl_na in NAM domain and then nested a 2 global distribution group from nam domain and apac domain.
If a user from NAM domain is trying to send an email to universal distribution group named gbl_na,the email is not flowing to users who is member of global distribution group in apac domain.But users from global distribution group in NAM domain is recieving emails.
appreciate for your help.