AS109 CISCO SYSTEMS, INC.

CISCOSYSTEMS - CISCO SYSTEMS, INC. · registered in the United States

IPv4 addresses1,141,50478 prefixes · 0.036% of announced IPv4

Rank in United States#93largest network in US by IPv4 space, of 18,338 · 0.08% of US

Rank worldwide#327of 79,396 networks with IPv4

IPv61 x /32 (65,536 x /48)52 prefixes

CountryUnited States18,679 ASNs registered there

Open AS109 in ASN lookup Look up an IP in this network (12.5.186.1) All networks in United States

IPv4 prefixes

All 78 prefixes, in address order.

12.5.186.0/23
12.19.88.0/21
12.159.148.0/22
64.100.0.0/15
64.102.0.0/17
64.102.128.0/18
64.102.192.0/19
64.102.224.0/20
64.102.240.0/21
64.102.248.0/23
64.102.250.0/23
64.102.252.0/22
64.103.0.0/16
64.104.0.0/18
64.104.64.0/19
64.104.96.0/20
64.104.112.0/21
64.104.120.0/22
64.104.124.0/24
64.104.125.0/24
64.104.126.0/23
64.104.128.0/17
66.187.208.0/20
72.163.0.0/22
72.163.4.0/24
72.163.5.0/24
72.163.6.0/23
72.163.8.0/21
72.163.16.0/20
72.163.32.0/19
72.163.64.0/18
72.163.128.0/18
72.163.192.0/19
72.163.224.0/20
72.163.240.0/23
72.163.242.0/23
72.163.244.0/22
72.163.248.0/22
72.163.252.0/22
103.60.32.0/22
111.223.8.0/22
128.107.0.0/20
128.107.16.0/20
128.107.32.0/20
128.107.48.0/21
128.107.56.0/21
128.107.64.0/18
128.107.128.0/17
144.254.0.0/16
161.44.0.0/16
171.68.0.0/14
173.36.0.0/16
173.37.0.0/17
173.37.128.0/20
173.37.144.0/23
173.37.146.0/23
173.37.148.0/22
173.37.152.0/21
173.37.160.0/19
173.37.192.0/18
173.38.0.0/16
173.39.0.0/17
173.39.128.0/18
173.39.192.0/21
173.39.200.0/23
173.39.202.0/23
173.39.204.0/22
173.39.208.0/20
192.118.76.0/22
192.133.192.0/19
192.133.224.0/20
192.133.240.0/22
192.135.250.0/24
198.133.219.0/24
198.135.0.0/21
204.69.198.0/23
204.69.200.0/24
216.128.32.0/19

IPv6 prefixes

All 52 prefixes.

2001:420::/41
2001:420:80::/44
2001:420:90::/46
2001:420:94::/46
2001:420:98::/45
2001:420:a0::/43
2001:420:c0::/42
2001:420:100::/40
2001:420:200::/39
2001:420:400::/38
2001:420:800::/37
2001:420:1000::/36
2001:420:2000::/35
2001:420:4000::/40
2001:420:4100::/40
2001:420:4200::/39
2001:420:4400::/41
2001:420:4480::/45
2001:420:4488::/45
2001:420:4490::/44
2001:420:44a0::/43
2001:420:44c0::/42
2001:420:4500::/40
2001:420:4600::/39
2001:420:4800::/37
2001:420:5000::/36
2001:420:6000::/35
2001:420:8000::/34
2001:420:c000::/41
2001:420:c080::/42
2001:420:c0c0::/43
2001:420:c0e0::/44
2001:420:c0f0::/45
2001:420:c0f8::/46
2001:420:c0fc::/46
2001:420:c100::/44
2001:420:c110::/45
2001:420:c118::/45
2001:420:c120::/45
2001:420:c128::/47
2001:420:c12a::/47
2001:420:c12c::/46
2001:420:c130::/45
2001:420:c138::/46
2001:420:c13c::/46
2001:420:c140::/42
2001:420:c180::/41
2001:420:c200::/39
2001:420:c400::/38
2001:420:c800::/37
2001:420:d000::/36
2001:420:e000::/35

Other ASNs named CISCO SYSTEMS, INC.

4 other networks use the same organisation name; together with AS109 they announce 1,149,184 IPv4 addresses.

ASNNameIPv4 addresses

AS398699WCCE - Cisco Systems Inc US3,072

AS396922TGRID-AS - Cisco Systems, Inc. US2,560

AS55219SOURCEFIRE-LABS - Cisco Systems, Inc. US1,536

AS36519CISCO-TTNA - CISCO SYSTEMS, INC. US512

Similar-sized networks in United States

ASNNameIPv4 addresses

AS72#90 SCHLUMBERGER-AS - Schlumberger Limited1,152,512

AS33659#91 CMCS - Comcast Cable Communications, LLC1,147,136

AS7155#92 VIASAT-SP-BACKBONE - ViaSat,Inc.1,143,296

AS5006#94 VOYANT - Inteliquent, inc.1,123,328

AS22284#95 AS22284-DOI-OPS - U.S. Department of the Interior1,086,720

AS22909#96 COMCAST-22909 - Comcast Cable Communications, LLC1,075,968

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources