How to choose DNS from openvpn PUSH string

[octopus]

I trying to use one preferred dns from my vpn provider, they come randomly in PUSH string.
Sometime it's the right one but often not.

I can extract DNS from vpn-log in right order with "grep" command.

vpn=1
grep -E "dhcp-option DNS" /tmp/vpnclient-$vpn.log  | cut -d ' ' -f3 | tail -n 2 | sort -n

wich give me:
46.227.67.134
192.165.9.158
and want to use first one: 46.227.67.134 but have redudance with: 192.165.9.158

in updown-client.sh, there is using:

if echo $option | grep "dhcp-option DNS"; then serverips="$serverips $(echo $option | sed "s/dhcp-option DNS //")"; fi

likely same as I do. Then it used by DNSVPN1

/usr/sbin/iptables -t nat -A DNSVPN1 -s 192.168.12.120 -j DNAT --to-destination 46.227.67.134

Howe can I make sure alway use first DNS and have second as redundance?

Thanks !

 

[ColinTaylor]

How are you determining which of the two addresses pushed is "the right one"?

At the moment the addresses are:
46.227.67.134
192.165.9.158

but what if tomorrow they were:
149.27.617.34
122.133.7.58

which one is the right one now?

 

[Zastoff]

Looks like we use the same vpn provider
I use the same DNS-Servers, But i use them with DNSCrypt-proxy (Those servers supports dnscrypt protocol v2 and i added them as static servers)
DNSCrypt-proxy handles so the fastest is used first.

 

[octopus]

How are you determining which of the two addresses pushed is "the right one"?

At the moment the addresses are:
46.227.67.134
192.165.9.158

but what if tomorrow they were:
149.27.617.34
122.133.7.58

which one is the right one now?

OK, There is only two DNS from my provider so it's alway same 2 ones.

 

[ColinTaylor]

OK, There is only two DNS from my provider so it's alway same 2 ones.

So do as @Zastoff does and hard-code the IP addresses into your application.

 

[octopus]

Looks like we use the same vpn provider
I use the same DNS-Servers, But i use them with DNSCrypt-proxy (Those servers supports dnscrypt protocol v2 and i added them as static servers)
DNSCrypt-proxy handles so the fastest is used first.

Ok, I know they support DnsCrypt and I want to try it. Do you get it working with DNS on router with wan?

 

[Zastoff]

Ok, I know they support DnsCrypt and I want to try it. Do you get it working with DNS on router with wan?

Yes it works fine.
I dont push the dns via vpn.. Accept DNS Configuration = Disabled

 

[octopus]

Yes it works fine.
I dont push the dns via vpn.. Accept DNS Configuration = Disabled

Thanks i give it a try later one when I have read up on this.

 

[octopus]

So do as @Zastoff does and hard-code the IP addresses into your application.

Easiest way to hard code it in is to in custom config use this, but then there is no redundancy.

pull-filter ignore "dhcp-option DNS 192.165.9.158"