http://www.commandlinefu.com/commands/view/5427/get-your-external-ip-address

https://ifconfig.me/

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

dig +short myip.opendns.com @resolver1.opendns.com

or

dig TXT +short o-o.myaddr.l.google.com @ns1.google.com

host myip.opendns.com resolver1.opendns.com

curl ifconfig.me

or

curl ipinfo.io/ip

lynx --dump http://www.whatismyip.com/ | grep -o '[0-9].*\.[0-9].*\.[0-9].*\.[0-9].*' -m1

or

elinks --dump http://www.whatismyip.com/ | grep -o '[0-9].*\.[0-9].*\.[0-9].*\.[0-9].*' -m1