How to define internal DNS server in Tor?

Support Core Tor
1

Hello,
I combined OpenVPN with Tor:

RunAsDaemon 1
DataDirectory /var/lib/tor_OpenVPN

## OpenVPN
VirtualAddrNetwork 20.192.0.0/10
AutomapHostsOnResolve 1
DNSPort 20.20.0.1:53530
TransPort 20.20.0.1:9040

But, when I connect to the VPN, I can no longer ping computers on the internal network by name (A DNS problem). I have a DNS server on my internal network and there is no problem when I use OpenVPN without Tor.

How can I tell Tor to use the internal DNS server?

Thank you.

2

Hello,
I think this question is useful for many people.
I changed the DNSPort 20.20.0.1:53530 line to DNSPort DNS_SERVER_IP:53 and I ran the Tor again, but I got the following error:

# tor -f /etc/tor/OpenVPN 
Nov 01 13:58:06.074 [notice] Tor 0.4.7.13 running on Linux with Libevent 2.1.12-stable, OpenSSL 3.0.11, Zlib 1.2.13, Liblzma 5.4.1, Libzstd 1.5.4 and Glibc 2.36 as libc.
Nov 01 13:58:06.074 [notice] Tor can't help you if you use it wrong! Learn how to be safe at https://support.torproject.org/faq/staying-anonymous/
Nov 01 13:58:06.074 [warn] Tor was compiled with zstd 1.5.2, but is running with zstd 1.5.4. For safety, we'll avoid using advanced zstd functionality.
Nov 01 13:58:06.074 [notice] Read configuration file "/etc/tor/OpenVPN".
Nov 01 13:58:06.076 [notice] You configured a non-loopback address '172.20.1.2:53' for DNSPort. This allows everybody on your local network to use your machine as a proxy. Make sure this is what you wanted.
Nov 01 13:58:06.076 [warn] You specified a public address '20.20.0.1:9040' for TransPort. Other people on the Internet might find your computer and use it as an open proxy. Please don't allow this unless you have a good reason.
Nov 01 13:58:06.081 [notice] You configured a non-loopback address '172.20.1.2:53' for DNSPort. This allows everybody on your local network to use your machine as a proxy. Make sure this is what you wanted.
Nov 01 13:58:06.081 [warn] You specified a public address '20.20.0.1:9040' for TransPort. Other people on the Internet might find your computer and use it as an open proxy. Please don't allow this unless you have a good reason.
Nov 01 13:58:06.081 [notice] Opening Socks listener on 127.0.0.1:9050
Nov 01 13:58:06.081 [notice] Opened Socks listener connection (ready) on 127.0.0.1:9050
Nov 01 13:58:06.081 [notice] Opening DNS listener on 172.20.1.2:53
Nov 01 13:58:06.081 [warn] Could not bind to 172.20.1.2:53: Cannot assign requested address
Nov 01 13:58:06.081 [notice] Opening Transparent pf/netfilter listener on 20.20.0.1:9040
Nov 01 13:58:06.081 [notice] Opened Transparent pf/netfilter listener connection (ready) on 20.20.0.1:9040
Nov 01 13:58:06.081 [notice] Closing partially-constructed Socks listener connection (ready) on 127.0.0.1:9050
Nov 01 13:58:06.081 [notice] Closing partially-constructed Transparent pf/netfilter listener connection (ready) on 20.20.0.1:9040
Nov 01 13:58:06.082 [warn] Failed to parse/validate config: Failed to bind one of the listener ports.
Nov 01 13:58:06.082 [err] Reading config failed--see warnings above.

What do you think to solve this problem? Do I need to configure a DNS server on the Tor server?

Thank you.