How can I look up my current external IP address?

DNS! It’s always the answer for your woes :)

While there are a myriad of HTTP servers for seeing your external IP address, you can also use one of the various DNS based services on offer.

These will give you an IPv4 flag. The -4 flag isn’t necessarily required but without explicitly providing it, you’ll be gambling on the return type.

> dig +short -4
> dig +short -4
> dig ANY +short -4
> dig TXT +short -4

and likewise, for IPv6

> dig AAAA +short -6
> dig TXT +short -6

You can read more, and see some other providers I left out, in this detailed StackOverflow thread but generally speaking, I’ve found OpenDNS’s resolver4 to be the fastest of the lot on offer.

A very handy thing to have aliased and way quicker than clicking 5 times to navigate to a webpage.