AS18403 The Corporation for Financing & Promoting Technology
2405:4800:4278::/46 - FPT-VN
inet6num: 2405:4800::/32 netname: FPT-VN country: VN descr: FPT Telecom descr: 2nd Floor, FPT Cau Giay Tower, 17 Duy Tan, Dich Vong Hau descr: Cau Giay District, Hanoi admin-c: FHIG1-AP tech-c: FHIG1-AP status: ALLOCATED PORTABLE mnt-by: MAINT-VN-VNNIC mnt-lower: MAINT-VN-FPT mnt-routes: MAINT-VN-FPT last-modified: 2017-11-19T09:10:20Z mnt-irt: IRT-VNNIC-AP source: APNIC irt: IRT-VNNIC-AP address: Ha Noi, VietNam phone: +84-24-35564944 fax-no: +84-24-37821462 e-mail: email@example.com abuse-mailbox: firstname.lastname@example.org admin-c: NTTT1-AP tech-c: NTTT1-AP auth: # Filtered mnt-by: MAINT-VN-VNNIC last-modified: 2017-11-08T09:40:06Z source: APNIC role: FPT HANOI IPADMIN GROUP address: FPT Telecom address: 2nd Floor, FPT Cau Giay Tower, 17 Duy Tan, Dich Vong Hau, Cau Giay District, Hanoi country: VN phone: +84-24-7601060 fax-no: +84-24-7262163 e-mail: email@example.com remarks: send spam reports to firstname.lastname@example.org admin-c: LVTL1-AP admin-c: LDP12-AP tech-c: TTH19-AP tech-c: BPD5-AP nic-hdl: FHIG1-AP mnt-by: MAINT-VN-FPT last-modified: 2017-11-19T08:34:13Z 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.