Öffentliche IP-Adresse ermitteln

$ wget -O - -q icanhazip.com
1.2.3.4

$ curl -L -s --max-time 10 http://checkip.dyndns.org | grep -Eo -m 1 '(digit:{1,3}.){3}digit:{1,3}'

$ linux -dump http://www.formyip.com/ | awk "/IP is/" | awk {'print $4'}