Re: Get the external IP address from a Linux box
- Date: Thu, 24 May 2018 17:16:08 -0400
- From: Miles Fidelman <mfidelman@xxxxxxxxxxxxxxxx>
- Subject: Re: Get the external IP address from a Linux box
On 5/24/18 4:22 PM, Erwan David wrote:
Le 05/24/18 à 22:17, Stefan Monnier a écrit :
Alberto Luaces <aluaces@xxxxxx> writes:
On the assumption that you are using a router of some kind, your public
IP address will be that of the router WAN port (cable, ADSL, etc.) and
there will be a method of determining that by connecting to the router
as an administrator. That method will depend entirely on the router.
If the router supports upnp and it is activated, you can check the
external IP in an device-independent way with
upnpc -l | grep ExternalIPAddress
The miniupnpc Debian package even comes with the `external-ip` script
which basically does the above.
I just tried it and it worked (tho only after I installed & enabled
miniupnpd on my OpenWRT router). Of course, the IP address that my
router gets could itself be an "internal IP" behind a NAT firewall of my
ISP, so even if `external-ip` does give an answer I'm not sure it's
guaranteed to be "the" external IP address.
You could also be natted to one pool, so get different addresses for
different connections, or even have different services natted to
different pools (eg because there is a transparent proxy for outgoing
On the assumption that you're connected to a NAT router - the easiest
way is to log into the admin port on the router - usually there's a
management interface that will tell you your external IP address.
In theory, there is no difference between theory and practice.
In practice, there is. .... Yogi Berra