46.252.48.0/20

inetnum:        46.252.48.0 - 46.252.59.255
netname:        BGBALCHIK
descr:          Balchik.net
country:        BG
admin-c:        MM26153-RIPE
tech-c:         MM26153-RIPE
status:         ASSIGNED PA
mnt-by:         IPACCT-MNT
created:        2010-12-20T13:18:12Z
last-modified:  2010-12-20T13:18:12Z
source:         RIPE
abuse-email:    office@balchik.net
abuse-c:        BAC21-RIPE
abuse-org:      ORG-LE9-RIPE

person:         Mihail Mihailov
address:        Balchik, Varnenska str, bl. 2
mnt-by:         IPACCT-MNT
phone:          +35957975034
nic-hdl:        MM26153-RIPE
created:        2010-12-16T22:16:13Z
last-modified:  2010-12-16T22:16:13Z
source:         RIPE

route:          46.252.48.0/20
descr:          Balchik.net
origin:         AS34841
mnt-by:         IPACCT-MNT
created:        2010-12-20T13:19:08Z
last-modified:  2010-12-20T13:19:08Z
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.