Get upstream DNS provider

To get the IP address of the server that is making the final DNS request:

nslookup whoami.akamai.net

or

dig whoami.akamai.net

Thanks, Barmar.

Get external IP address via command line

nslookup:

nslookup myip.opendns.com resolver1.opendns.com

PowerShell:

(Invoke-WebRequest -uri http://ifconfig.me/ip).Content

Invoke via Command Prompt:

PowerShell -Command "(Invoke-WebRequest -uri http://ifconfig.me/ip).Content"

Update BIND root hints file

Use Wget to download an update the BIND root hints:

wget ftp://ftp.internic.net/domain/named.cache -O db.root

Change DNS settings from command line

Get the list of interface names:

netsh interface ip show config

Change interface named "Ethernet" to use DHCP for DNS:

netsh interface ipv4 set dnsservers name="Ethernet" source=dhcp

Set primary and secondary DNS servers for interface named "Ethernet":

netsh interface ip set dns "Ethernet" static 192.168.0.50
netsh interface ip add dns "Ethernet" 192.168.0.51 index=2

Delete a DNS server from interface "Ethernet":

netsh interface ip delete dnsserver "Ethernet" 192.168.0.51