212.73.154.0/24

inetnum:        212.73.154.0 - 212.73.154.255
netname:        NETERRA-BSC_for_SMEs-NET
country:        BG
admin-c:        KG17680-RIPE
tech-c:         KM8359-RIPE
mnt-routes:     MNT-NETERRA
mnt-routes:     MNT-BSC_for_SMEs
mnt-domains:    MNT-BSC_for_SMEs
status:         ASSIGNED PA
mnt-by:         MNT-NETERRA
created:        2018-08-08T09:04:46Z
last-modified:  2019-03-20T10:01:47Z
source:         RIPE

person:         Katia Goranova
address:        BG
phone:          +359 888898137
nic-hdl:        KG17680-RIPE
mnt-by:         MNT-NETERRA
created:        2018-08-02T11:34:45Z
last-modified:  2018-08-02T11:34:45Z
source:         RIPE

person:         Kalin Minev
address:        Ruse, Bulgaria
phone:          +359896544583
nic-hdl:        KM8359-RIPE
mnt-by:         MNT-NETERRA
created:        2018-08-10T11:41:11Z
last-modified:  2018-08-10T11:41:11Z
source:         RIPE

route:          212.73.154.0/24
origin:         AS34770
mnt-by:         MNT-BSC_for_SMEs
created:        2019-03-20T10:07:58Z
last-modified:  2019-03-20T10:07:58Z
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.