General Info






AS10771 AT&T Internet Services

United States


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Whois Details

V6NetHandle:    NET6-2001-1890-E100-1
OrgID:          CERF
Parent:         NET6-2001-1890-1
NetName:        ATT-CERF
NetRange:       2001:1890:E100:: - 2001:1890:E1FF:FFFF:FFFF:FFFF:FFFF:FFFF
NetType:        reallocation
RegDate:        2012-05-30
Updated:        2012-05-30
Source:         ARIN

OrgID:          CERF
OrgName:        CERFnet
Street:         5738 Pacific Center Blvd
City:           San Diego
State/Prov:     CA
Country:        US
PostalCode:     92121
Comment:        Contact AT&T Abuse ( for policy abuse issues.
Comment:        All policy abuse issues sent to other POCs will be disregarded.
RegDate:        1989-04-18
Updated:        2017-01-28
OrgTechHandle:  NETWO10-ARIN
OrgAdminHandle: NETWO10-ARIN
OrgAbuseHandle: ATTAB-ARIN
Source:         ARIN


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.