Adds a nameserver to the DNS base
$ip
Adds a nameserver to the evdns_base.
ip
The nameserver string, either as an IPv4 address, an IPv6 address, an IPv4 address with a port ( IPv4:Port ), or an IPv6 address with a port ( [IPv6]:Port ).
IPv4:Port
[IPv6]:Port
Returns true on success or false on failure.
true
false