RES_NS parameter    ==  RES_NS=nsList
            nsList  ==  dnsServ[,nsList]
           dnsServ  ==  dnsServer[//socksV5Host] | END.
                    --  default: depend on RES_CONF

Specify a DNS server to be used: dnsServer is a host name or an IP-address of the host name DNS server, which may optionally be followed by port number, like "host:8053" when the port number is not standard port(53). With "dnsServer//socksV5Host", a DNS server beyond a firewall can be referred through the specified Socks V5 server. The Socks server is specified by its IP address with an optional port number like "192.168.1.1:2080".

By default, name servers listed in "resolv.conf" are added to the list of DNS servers to be used. A special dnsServ name ".END" disables to adding such name servers. For example, RES_NS="192.168.1.1,END." means using 192.168.1.1 only regardless of "resolv.conf".