OpenVPN DNS Bug/Brokeness

Issues related to configuring your network
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matt2020
Posts: 13
Joined: 2020/01/20 07:26:39

OpenVPN DNS Bug/Brokeness

Post by matt2020 » 2020/03/07 19:01:32

On CentOS 8.1 using :
openvpn-2.4.8-1.el8.x86_64 : A full-featured SSL VPN solution
Repo : epel

Using an .OPVN file known to work with other systems.

# openvpn --config Good.ovpn
...
Sat Mar 7 10:45:45 2020 PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1 bypass-dhcp,dhcp-option DNS 10.X.9.1,dhcp-option DNS 8.8.4.4,route-gateway 10.X.9.1,topology subnet,ping 10,ping-restart 120,ifconfig 10.X.9.3 255.255.255.0,peer-id 0,cipher AES-256-GCM'
...
Sat Mar 7 10:48:52 2020 Initialization Sequence Completed

VPN Connects successfully and is usable BUT :

OpenVPN Server pushed 2 DNS :
DNS 10.X.9.1
DNS 8.8.4.4

NO DNS changes are made to system !

$ more /etc/resolv.conf
# Generated by NetworkManager
nameserver 192.168.X.X

VPN IS USING LOCAL DNS NOT PUSHED DNS.

Can others confirm this bug ?

This is also true when importing a VPN into GUI it appears.

UPDATE :

Just created an CentOS8 VM from scratch and reproduced the problem there.
Probably should not use OpenVPN until issue is fixed unless you dont care about DNS leakage.

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