31.187.0.0/19

inetnum:        31.187.0.0 - 31.187.31.255
netname:        UPC-IRELAND
descr:          UPC Communications Ireland Limited
country:        IE
admin-c:        DUMY-RIPE
tech-c:         DUMY-RIPE
remarks:        =====================================================
remarks:        Contact abuse@upc.ie concerning criminal
remarks:        activities like spam, hacks, portscans
remarks:        =====================================================
status:         LIR-PARTITIONED PA
mnt-by:         MNT-LGI
notify:         ripe@lgi.com
created:        2014-02-12T09:38:50Z
last-modified:  2014-04-15T08:49:14Z
source:         RIPE
remarks:        ****************************
remarks:        * THIS OBJECT IS MODIFIED
remarks:        * Please note that all data that is generally regarded as personal
remarks:        * data has been removed from this object.
remarks:        * To view the original object, please query the RIPE Database at:
remarks:        * http://www.ripe.net/whois
remarks:        ****************************


organisation:   ORG-UTKS1-RIPE
org-name:       UPC Polska Sp. z o.o.
org-type:       LIR
address:        Dummy address for ORG-UTKS1-RIPE
e-mail:         unread@ripe.net
abuse-c:        UPA2-RIPE
mnt-ref:        RIPE-NCC-HM-MNT
mnt-ref:        MNT-LGI
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         MNT-LGI
created:        2004-04-17T11:48:28Z
last-modified:  2019-11-13T10:45:44Z
source:         RIPE
remarks:        ****************************
remarks:        * THIS OBJECT IS MODIFIED
remarks:        * Please note that all data that is generally regarded as personal
remarks:        * data has been removed from this object.
remarks:        * To view the original object, please query the RIPE Database at:
remarks:        * http://www.ripe.net/whois
remarks:        ****************************

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.