Assign CNAME for one subdomain?

[Florian Effenberger]

Hi there,

I have a question regarding BIND9, hope you can help me.

Assume we have a domain name (for a school) like ourschool.com. This domain
name is hosted, and the DNS servers are at our ISP and resolve to a static
IP of a webserver in a datacenter.

Now we have an onsite internet gateway (a router) which is a local
webserver. From within our school, it is reachable via router.school
(.school is the internal "domain", we have own inhouse DNS servers). From
outside, we have a dynamic DNS entry, so it resolves as router.ourschool.com

Now, when someone from within our school calls router.ourschool.com rather
then router.school, he gets connected to the external IP. However, I would
like to have him connect to the internal IP.

So, I need to set a single subdomain to a CNAME on our local DNS servers,
like

router.ourschool.com. IN CNAME router.school.

However, this does not seem to work, BIND always complains. Is there any
possibility of achieving that?

In short: Our local bind should query the regular DNS for *.ourschool.com,
EXCEPT router.ourschool.com, which should be CNAMED to router.school

Thanks a lot!
Florian