inet6num: 2001,b00,,/29 netname: IT-FASTWEB-20030213 country: IT org: ORG-FA7-RIPE admin-c: IRS4-RIPE tech-c: IRS4-RIPE status: ALLOCATED-BY-RIR notify: Fastweb_MNT@fastweb.it mnt-by: RIPE-NCC-HM-MNT mnt-by: FASTWEB-MNT mnt-routes: FASTWEB-MNT created: 2012-10-03T13,54,36Z last-modified: 2016-09-12T11,53,34Z source: RIPE organisation: ORG-FA7-RIPE org-name: Fastweb SpA org-type: LIR address: Via Caracciolo 51 address: 20155 address: Milano address: ITALY phone: +390245451 fax-no: +390245454811 mnt-ref: FASTWEB-MNT mnt-ref: RIPE-NCC-HM-MNT mnt-by: RIPE-NCC-HM-MNT mnt-by: FASTWEB-MNT admin-c: AL510-RIPE admin-c: ER1255-RIPE admin-c: DP4556-RIPE admin-c: EZ1397-RIPE admin-c: GG8279-RIPE admin-c: FM5655-RIPE admin-c: IRS4-RIPE admin-c: AC26449-RIPE abuse-c: FA5264-RIPE created: 2004-04-17T11,31,05Z last-modified: 2016-09-12T11,54,02Z source: RIPE e-mail: IP.RegistrationService@fastweb.it role: IP Registration Service address: Via Caracciolo, 51 address: 20155 Milano MI address: Italy e-mail: IP.RegistrationService@fastweb.it remarks: trouble, remarks: trouble, In case of improper use originating from our network, remarks: trouble, please mail customer or firstname.lastname@example.org remarks: trouble, admin-c: GR417-RIPE tech-c: AL510-RIPE tech-c: DP4556-RIPE nic-hdl: IRS4-RIPE notify: IP.RegistrationService@fastweb.it mnt-by: FASTWEB-MNT created: 2002-05-02T15,00,48Z last-modified: 2006-06-30T12,27,52Z source: RIPE abuse-mailbox: email@example.com route6: 2001,b00,,/29 descr: Fastweb Networks ipv6 block origin: AS12874 remarks: 1st block IPV6 released to it.fastweb local registry mnt-by: FASTWEB-MNT remarks: In case of improper use originating from our network, remarks: please mail customer or firstname.lastname@example.org created: 2012-10-08T08,45,15Z last-modified: 2012-10-08T08,45,15Z source: RIPE
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.