Currently the Songkick API is served from only one IP address, you can
discover this IP by doing a DNS lookup for api.songkick.com
$ host api.songkick.com
api.songkick.com has address 94.228.36.41
That should be sufficient for your service provider's ACL.
It's possible that we'll change this at some stage, so that the API
lives on multiple IPs or different addresses. We'll try to remember to
post here if that's going to happen.
Please always use the hostname in API calls and only add it to access
restrictions when absolutely necessary. We may rely on people using a
valid hostname (and sending it in the Host: header).
Regards,
Graham
--
Head of TechOps, Songkick.com