177.129.8.0/21

inetnum:    177.129.12/22
status:     allocated
owner:      CITTA TELECOM LTDA
city:       Rio de Janeiro
country:    BR
owner-c:    CIT4
tech-c:     CIT4
abuse-c:    CIT4
inetrev:    177.129.12/24
nserver:    NS1.CITTATELECOM.NET.BR
nserver:    NS2.CITTATELECOM.NET.BR
inetrev:    177.129.13/24
nserver:    NS1.CITTATELECOM.NET.BR
nserver:    NS2.CITTATELECOM.NET.BR
inetrev:    177.129.14/24
nserver:    NS1.CITTATELECOM.NET.BR
nserver:    NS2.CITTATELECOM.NET.BR
inetrev:    177.129.15/24
nserver:    NS1.CITTATELECOM.NET.BR
nserver:    NS2.CITTATELECOM.NET.BR
created:    2014-01-15
changed:    2014-01-15
source:     LACNIC


nic-hdl:     CIT4
person:      Citta Telecom
e-mail:      CIT4@NUMERACAO.REGISTRO.BR
address:     Av. das Nações Unidas, 11541, 7º andar
address:     04578-000 - Rio de Janeiro - RJ
country:     BR
phone:       +55 21 55093511 []
created:     20130405
changed:     20130405

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.