RDAP IP Networks

[Skybound1]

When performing RDAP IP Whois, the library enforces the use of an IP address. However, there are cases where it is useful to also provide details of the range we are interested in. For example, querying RDAP for 8.8.8.8 would return information regarding the encompassing /24, however if we wanted information for the encompassing /9, we would need to provide a network size. This appears to be supported at least within ARIN:

IP Networks
Queries for information about IP networks are of the form:

<rdap-url>/ip/<search-term> or /ip/<address>/<prefix>

where the path segment following ip is either an IPv4 dotted decimal or IPv6 [RFC5952] address (i.e., 2001:500:11::) or an IPv4 or IPv6 Classless Inter-domain Routing (CIDR) [RFC4632] notation address block (i.e., 12.0.0.0/8).

Query Examples

https://rdap.arin.net/bootstrap/ip/2001:500:11:: https://rdap.arin.net/bootstrap/ip/12.0.0.0/8

Example queries:

https://rdap.arin.net/registry/ip/8.8.8.8/16
https://rdap.arin.net/registry/ip/8.8.8.8

Could we get a way to provide this extra bit of information, for example a flag into IPWhois.lookup_rdap

[secynic]

Requested changes in the PR. Still need to test this to make sure it doesn't cause errors in other parts of the lib.