Domains in a VPN? Local domains?

[arnekolja]

Hello,

I am setting up ispCP on a server that has two IPs: An external one and one for VPN purposes. Both are selectable inside ispCP and the internal one is attached to the tun interface, so this should work fine. But now I got a question regarding connecting actual domains: Would the internal DNS "override" the DNS handling while inside the VPN, so I can use domain.com from inside the VPN? Or do I have to do something like domain.com.local (for example)? If the latter one: How do I achieve this? isCP tells me it takes only official top level domains, so it won't work that way.

Any help is welcome, so thanks in advance :-)

Arne