Can't push DNS option to Windows OpenVPN clients

Routers
1

I am running a OpenVPN Server on a MT3000 in drop-in gateway mode firmware 4.8.3 op24. Everything works except my Windows clients don’t get the correct DNS Server assigned. When a Windows client connects, “ERR_INVALID_OPTION_DNS: option_error” is seen in the client logs, ‘dhcp-option’ must have exactly 3 arguments”

ovpn_invalid_dns_option_error
ovpn_invalid_dns_option_error595×1020 70.9 KB

The “push dhcp-option” configured in /etc/openvpn/ovpn/server.ovpn is ignored

The “push dhcp-option” in /var/ovpnserver/ovpnserver is “push “dhcp-option DNS “ which is indeed missing the 3rd argument.

var_ovpnserver
var_ovpnserver634×297 2.17 KB

What is the /var/ovpnserver/openvpnserver file getting this DNS server setting from, and how can I assign it the proper value. Manually editing the file in var doesn’t work because it just resets whenever the OpenVPN server is restarted and the setting never applies

2

See exactly what process owns and writes the runtime file

ls -la /var/ovpnserver/
cat /var/ovpnserver/ovpnserver

To know what writes the file at boot.

There maybe a glinet specific configuration file but im not sure of it.

3

I think GLinet is reading uci variables to generate the /var/ovpnserver/ovpnserver file, but I can’t figure out which variable it is trying to read the DNS variable from.

4

Hi

Thanks for the report.
We have reproduced the issue locally and will ask the R&D team to fix it.

For now, you can try manually editing /lib/netifd/proto/ovpnserver.sh to address the issue.

image
image2358×1391 217 KB