Load Inbound can't nslookup subdomain from internet

hi all

 

my new f5 , the present i'm facing loadbalancing inbound , the users in internet with setting dns server is 8.8.8.8 can't nslookup subdomain . i have dns server inside manage domain of company , on this dns server have many subdomain for much services.

 

dns server ( ip:A)-------------internal------------F5-----------2lines internet

 

F5 config:

 

sefl Ip internet :10.0.33.3

 

ip public 1: 118.69.x.y

 

ip public 2: 222.255.x.y

 

F5 have config virtual server to forward port UDP 53 to DNs server in inside

 

F5 have config 2 virtual servers to access services web inside with port 80 . the end users from internet nslookup subdomain and access services web ok.

 

I had config inbound to dns server delegated subdomain to the BigIP ( LC ) , but users from internet can't nslookup subdomain , this errors *** UnKnown can't find jobs.mycompany.com.vn: Query refused

 

This is information config inbound:

 

the F5 :

 

hostname :wip.mycompany.com.vn

 

listener ip : 10.0.33.3 , all vlan

 

wideip : www.wip.mycompany.com.vn

 

and select 2 virtual server access services web

 

the DNS server:

 

- delegated subdomain to F5

 

wip NS wip.mycompany.com.vn.

 

wip A 10.0.33.3

 

www CNAME www.wip.mycompany.com.vn.

 

 

The present users dns 8.8.8.8 from internet can not nslookup www.mycompany.com.vn , but user other from internet with setting dns is 118.69.x.y ( this ip forward port 53 to DNS server inside) then nslookup subdomain www.mycompany.com.vn OK

 

pls help me

 

thanks all