163.166.138.0/24

inetnum:        163.166.0.0 - 163.166.255.255
netname:        BAWNET2
descr:          British Airways PLC
country:        GB
admin-c:        TWIP1-RIPE
tech-c:         CC1493-RIPE
status:         LEGACY
notify:         eBiz.Reports@britishairways.com
remarks:        Please report abuse at 'abuse@ba.com'
mnt-by:         AS5462-MNT
mnt-by:         AS5089-MNT
created:        1970-01-01T00:00:00Z
last-modified:  2016-02-11T15:33:19Z
source:         RIPE

role:           Virgin Media
address:        Media House
address:        Bartley Wood Business Park
address:        Hook
address:        Hampshire
address:        RG27 9UP
e-mail:         ipam@virginmedia.co.uk
remarks:        To report abuse:
remarks:        file an online case @ http://netreport.virginmedia.com/netreport/
admin-c:        IPAM2-RIPE
tech-c:         IPAM2-RIPE
nic-hdl:        TWIP1-RIPE
notify:         ipam@virginmedia.co.uk
notify:         Email Abuse & Blacklist & SPF contact <postmaster@virginmedia.com>
mnt-by:         AS5089-MNT
created:        2002-07-04T20:24:49Z
last-modified:  2019-11-03T13:47:53Z
source:         RIPE

person:         Chris Clark
address:        British Airways PLC
address:        Waterside (HDA2)
address:        PO Box 365
address:        Harmondsworth
address:        UB7 0GB
address:        England, UK
phone:          +44 208 738 5432
phone:          +44 181 562 1949
e-mail:         chris.p.clark@britishairways.com
nic-hdl:        CC1493-RIPE
notify:         eBiz.Reports@britishairways.com
mnt-by:         AS5462-MNT
created:        2003-04-30T13:18:17Z
last-modified:  2003-04-30T13:18:17Z
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.