Rotation of DNS servers in your server list. If you have more DNS servers in your resolv.conf every new request will be send to next server and finally again to first DNS server. Default is disabled. To enable: DNS.defaults["server_rotate"]=1
patch
This is included in py3dns 3.0.0.
Included in pydns-2.3.5
patch
This is included in py3dns 3.0.0.
Included in pydns-2.3.5