forward sub domain

[chua_jose]

Hy to all,
i have a domain example.com, it is in my server. I need to create a sub domain that point at an ip and this ip will be the one that resolves the sub domain.
I done like that, and it was working correctly, but now don´t work.
I explain to you like I it have now.
I create a site with name subdomain.example.com, with ip of my server.
I create un DNS A apoint to ip of other external DNS server, and DNS of subdomain, I put the ip of the external server dns
The personnel of the new server dns they say to me that the problem is in my server.
I have several domains like that with Different companies, and now none works

Thanks

[jon]

I would make sure you're adding/changing the A records at the authoritative DNS server for those domains. Try pinging the domain name or subdomain and see if it returns the IP you're expecting. Try something like dnsstuff.com and see what the results are