163.13.0.0/16

inetnum:        163.13.0.0 - 163.13.255.255
netname:        T-TKU.EDU.TW-NET
descr:          Taipei Taiwan
country:        TW
admin-c:        ES31-TW
tech-c:         ES31-TW
mnt-by:         MAINT-TW-TWNIC
remarks:        This information has been partially mirrored by APNIC from
remarks:        TWNIC. To obtain more specific information, please use the
remarks:        TWNIC whois server at whois.twnic.net.
changed:        chuang@mail.moe.gov.tw 19920706
status:         ASSIGNED NON-PORTABLE
source:         TWNIC


person:         Edwin
address:        Taipei County Taiwan
country:        TW
e-mail:         abuse@tku.edu.tw
nic-hdl:        ES31-TW
changed:        hostmaster@twnic.net.tw 20041126
source:         TWNIC

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.