2604:a580::/40 - NET-CONTEGIX-STLDC01-V6-1304
V6NetHandle: NET6-2604-A580-1 OrgID: CONTE-25 Parent: NET6-2600-1 NetName: NET-CONTEGIX-STLDC01-V6-1304 NetRange: 2604:A580:: - 2604:A580:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF NetType: allocation OriginAS: 1610 RegDate: 2013-04-08 Updated: 2016-05-17 TechHandle: HOSTM1486-ARIN NOCHandle: NOCCO14-ARIN AbuseHandle: ABUSE2391-ARIN Source: ARIN OrgID: CONTE-25 OrgName: Contegix CanAllocate: Street: 210 N. Tucker Blvd. Street: Suite 600 City: St. Louis State/Prov: MO Country: US PostalCode: 63101 RegDate: 2009-04-13 Updated: 2019-04-23 OrgTechHandle: HOSTM1486-ARIN OrgNOCHandle: NOCCO14-ARIN OrgAdminHandle: HOSTM1486-ARIN OrgAbuseHandle: ABUSE2391-ARIN Source: ARIN
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.