How can I get my external IP address from behind a NAT?

Moses420ca · 06-15-2005, 10:38 AM

Hi.
I behind a NAT enabled router and I need to find my external IP address for logging purposes. What I want is a command line tool that looks like this.

Code:

getip >> iplog.log

Thanks for any help. Drew

Kdr Kane · 06-15-2005, 11:33 AM

You can't get it directly from the machine you are on. You'll need to get a machine on the internet to tell you.

Here's one:
http://www.whatismyip.com/

demian · 06-15-2005, 11:49 AM

Depending on the type of router you have this might not be possible. If your router speaks snmp you can use that to grep the WAN IP address of the router. If it doesn't I wouldn't know how to do it.

When I do

snmpwalk -v2c -c public myrouter ip (myrouter is the DNS name of the router and ip is not an ip address but the literal string "ip")

my router tells me anything ip related. The WAN ip is under ipAdEntAddr.

Moses420ca · 06-15-2005, 12:56 PM

Thank you. I don't have that command and before I find it I'll ask this. I have a command that works but it outputs more then just the IP address. I tried a few things but all in all, I ended up in perl.

Code:

#!/usr/bin/perl

my $external_ip;

my $external_ip = `lynx -dump "http://checkip.dyndns.org"`;
my $external_ip =~ s/Current IP Address: //;

print("$external_ip\n");

All I want is the IP address but it doesn't output anything. Maybe my regex skills arn't what they use to be.

Looking_Lost · 06-15-2005, 01:55 PM

This works for me:

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

Moses420ca · 06-15-2005, 03:06 PM

I still don't understand why this regex won't work... Thanks. That's a nice command there. Although mine has a carriage-return before and after the ip address that I can't seem to get rid of. It looks like this;

Code:

123.123.123.123

frenchn00b · 10-23-2008, 12:07 PM

could someone make a package tar.gz for a new sourceforge one:

getip ??

based on getip.com??

ngibsonau · 11-23-2009, 03:18 AM

Here is a solution I made to solve Moses420ca's problem using SNMP.
For my router I log in to routers web admin interface and
Enable SNMP Agent
Enable SNMP Traps

Then run this script filename "getip"
passing in the ip or DNS name of the router
If you don't pass any parameters it looks up the default gateway

Code:

#!/bin/bash

# output external IP address from behind NAT using SNMP on router


if [ "$1" != "" ]; then
  ROUTER="$1"
else
  ROUTER=$(route | grep default | awk '{ print $2 }')
fi

# echo Router: $ROUTER

ROUTERIP=$(nslookup mygateway1.ar7 | tail -2 | grep Address | awk '{ print $2}')

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

rimote media · 10-28-2010, 10:54 AM

We have our own webservers and did not want to use a third party like dyndns or use snmp. This is our solution:

1. Create a php file in your webhosting account:

getip.php

2. put this code in it:

<?php echo $_SERVER["REMOTE_ADDR"]; ?>

3. Now you have 2 options to use it:

A. go to the URL with a browser and you will see your IP-adres.
B. use html2text or like to get the output in your Linux system.

We use Debian and html2text does not have the right capabilities so we use this:

# apt-get install curl

# curl -s http://yourdomainname/getip.php | html2text

Now you get a nice output that works on any Linux PC without the hassle of snmp or use third party tools. All under your control.

Hope this helps somebody...

estabroo · 10-28-2010, 10:51 PM

Quote:

Originally Posted by Moses420ca

Code:

#!/usr/bin/perl

my $external_ip;

my $external_ip = `lynx -dump "http://checkip.dyndns.org"`;
my $external_ip =~ s/Current IP Address: //;

print("$external_ip\n");

Change that s/// line to
$external_ip =~ s/.*?([\d\.]+).*/$1/;

sergani · 03-13-2011, 06:18 AM

I know it's a very old thread, but you never know

I've written this very simple script for the above request:

Code:

#!/bin/bash
#
# Output public IP from behind NAT using checkip.dyndns.org
#
printf "Your Current IP address is: "
curl -s http://checkip.dyndns.org/ | cut -d ' ' -f 6 | sed s/"body\|html\|<\|>\|\/"//g
#
# Respect for opensource... Respect for sharing!!
# Script written by Sergani ... msergani@gmail.com

The output should be something like this:

Code:

Your Current IP address is: XYZ.XYZ.XYZ.XYZ

If you do not want the text at the beginning of your line, for scripting purposes for example, you may just remove the "printf" line

You may then place this script file (name it getip for example) in your /bin/ directory, change it's permission for all users (or the root only, as you like) to be able to execute it:

Code:

For all users:
chmod a+x /bin/getip
For root only:
chmod ug+x /bin/getip

That's all

I hope it helps, and I would ask that if you were to use the script, to not forget including my bottom lines.. very much appreciated guys!!

David the H. · 03-13-2011, 08:42 AM

I went even further for a script I wrote and created the following simple function that queries a random ip site. All of the ones I use output a plain-text address, so there's no html to filter out. Some of them do unfortunately tack a newline onto the end, however, but it's easy enough to remove those as necessary.

Code:

get-current-ip() {

xc=1
until (( xc == 0 )) ; do

     case $(( RANDOM % 6 )) in

          0) ip=$(wget -t 2 -T 5 -q -O- http://showip.codebrainz.ca/) ;;
          1) ip=$(wget -t 2 -T 5 -q -O- http://www.whatismyip.com/automation/n09230945.asp) ;;
          2) ip=$(wget -t 2 -T 5 -q -O- http://www.showmyip.com/simple/) ;;
          3) ip=$(wget -t 2 -T 5 -q -O- http://cfaj.freeshell.org/ipaddr.cgi) ;;
          4) ip=$(wget -t 2 -T 5 -q -O- https://secure.informaction.com/ipecho/) ;;
          5) ip=$(wget -t 2 -T 5 -q -O- http://icanhazip.com/) ;;

     esac

     xc=$?

done

echo -n "${ip//[^0-9.]}"   #if you don't want a trailing newline
#echo "$ip"                #if you want or don't mind newlines
}

get-current-ip

You can of course add additional sites of your own, but be careful how you construct the command, as the loop uses wget's exit code to determine if it successfully retrieved the address. Do any text filtering outside the loop after it's finished.

_jerry_ · 04-23-2011, 07:05 AM

This is one way that works for me:

wget -O - -q icanhazip.com

This site responds to your request by returning your IP

Make an executable file name it whatever you'd like and off you go..... ;-)

redir · 08-02-2011, 10:37 AM

Quote:

Originally Posted by _jerry_

This is one way that works for me:

wget -O - -q icanhazip.com

This site responds to your request by returning your IP

Make an executable file name it whatever you'd like and off you go..... ;-)

Dude, you just made my day. Thanks

ADX · 08-04-2011, 01:41 AM

How about just:

Code:

curl whatismyip.org