AS17987 .au Domain Administration
2407:6e00:5::/48 - AUDA
inet6num: 2407:6e00:5::/48 netname: AUDA descr: .au Domain Administration Limted descr: ccTLD Manager of the .au domain space descr: Australia country: AU admin-c: AK294-AP tech-c: AK294-AP status: ASSIGNED NON-PORTABLE mnt-by: MAINT-AU-AUDA mnt-lower: MAINT-AU-AUDA mnt-routes: MAINT-AU-AUDA mnt-irt: IRT-AUDA-AU last-modified: 2013-05-31T03:08:03Z source: APNIC person: Adam King nic-hdl: AK294-AP e-mail: email@example.com address: Lvl 17, 1 Collins St address: Melbourne VIC 3000 address: phone: +61-383414111 fax-no: +61-383414112 country: AU mnt-by: MAINT-AU-AUDA last-modified: 2017-09-20T08:12:35Z source: APNIC irt: IRT-AUDA-AU address: Lvl 17, 1 Collins St address: Melbourne VIC 3000 address: e-mail: firstname.lastname@example.org abuse-mailbox: email@example.com admin-c: AK294-AP tech-c: AK294-AP auth: # Filtered mnt-by: MAINT-AU-AUDA last-modified: 2017-10-30T20:34:18Z source: APNIC
IP address ranges, or netblocks, are groups of related IP addresses. They are usually represented as a base IP address, followed by a slash, and then a netmask which represents how many IP addresses are contained within the netblock. This format is known as CIDR. You'll also sometimes see netblocks given as a start ip address, and an end ip address, or an ip address range.
Traffic works its way around the internet based on the routing table, which contains a list of networks and their associated netblocks.