[varenc]

I love using ipinfo.com for the extra details it provides like hostname, ISP, ASN, etc.

   $ curl ipinfo.io/json

or you can look up these details for any other IP:

   $ curl ipinfo.io/18.18.18.18

[reincoder]

We have a CLI as well: https://github.com/ipinfo/cli

It has a ton of bells and whistles, including summarize IPs, bulk enrichment, grepip, and a ton of network-related tools. I was writing a series of blog posts on the CLI, but I think the series got too long and left users to discover the features of the CLI on their own.