AS12276 San Francisco Metropolitan Internet Exchange (SFMIX)
2620:11a:b000::/44 - SFMIX-V6-MANAGEMENT
V6NetHandle: NET6-2620-11A-B000-1 OrgID: SFMIES Parent: NET6-2620-1 NetName: SFMIX-V6-MANAGEMENT NetRange: 2620:11A:B000:: - 2620:11A:B00F:FFFF:FFFF:FFFF:FFFF:FFFF NetType: assignment OriginAS: 12276 RegDate: 2014-07-10 Updated: 2014-07-10 Source: ARIN OrgID: SFMIES OrgName: San Francisco Metropolitan Internet Exchange (SFMIX) CanAllocate: Street: 365 Main Street City: San Francisco State/Prov: CA Country: US PostalCode: 94105 RegDate: 2006-06-27 Updated: 2013-02-03 OrgAdminHandle: MPE54-ARIN OrgAbuseHandle: STRA-ARIN OrgTechHandle: STRA-ARIN OrgTechHandle: TP47-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.