How to learn external IP(外部IP)

using browser to check
www.whatismyip.com
http://checkip.dyndns.org:8245/
http://ipid.shat.net/iponly/


lynx -dump http://whatismyip.com | awk ‘/Your/{print $5}’
lynx -dump http://whatismyip.org/

wget -qO - http://cfaj.freeshell.org/ipaddr.cgi

html2text http://checkip.dyndns.org | cut -c21-35

snmpwalk -v 2c -c public $ROUTERIP ip | grep ipAdEntAddr |grep -v $ROUTERIP |grep -v 127.0.0.1 | awk '{ print $4 }'

#!/bin/bash
wget http://www.whatismyip.com/automation/n09230945.asp -O - -o /dev/null
echo