$ query “AS5400” --type=asn → 1 result(s)

AS5400 — BT

British Telecommunications PLC

AS5400 is a major transit provider operated by British Telecommunications PLC, based in the United Kingdom since 2002. The network announces a solid 697 600 IPv4 addresses, including a /16. Supports IPv6.

  • Top 5% — Top 5% of all autonomous systems by reach and degree

Basic Information

Country
🇬🇧 United Kingdom
Category
Internet Service Provider
Network Role
Major Transit
Data Origin
Authoritative — Metadata from authoritative RIR registry (ARIN, RIPE, APNIC, etc.)
Registered
August 29, 2002
Last Changed
March 04, 2026
Last Seen
March 04, 2026

Prefix Summary

IPv4 Prefixes (raw / aggregated)
65 / 56
IPv6 Prefixes (raw / aggregated)
14 / 6
IPv4 Addresses
697 600
Largest IPv4 Prefix
/16 (65 536 addresses)
Largest IPv6 Prefix
/23
Geolocated Countries
🇸🇪 SE (17 IPs), 🇬🇧 GB (53 IPs), 🇩🇪 DE (431 IPs), 🇺🇸 US, 🇳🇱 NL, 🇧🇪 BE, 🇨🇭 CH, 🇪🇸 ES, 🇨🇿 CZ, 🇮🇹 IT, 🇫🇷 FR, 🇩🇰 DK, 🇱🇺 LU, 🇮🇪 IE and 33 more
Prefix Changed
March 04, 2026

Reputation

Reputation
Pristine — 0 flagged IPs out of 697 600 total (0.00%)

Connectivity Summary

Upstream Providers
3 upstream autonomous systems providing transit
Peers
90 autonomous systems exchanging traffic without transit fees
Downstream Customers
64 downstream autonomous systems buying transit
Degree
158 unique BGP neighbors (providers + customers + peers)
Reach
652 — customer cone size measuring network influence
Degree Rank
#905
Reach Rank
#675

Upstream Providers (3)

  • AS3356 — LEVEL3 (Tier-1 transit)
  • AS1299 — TWELVE99 (Tier-1 transit)
  • AS4637 — ASN-TELSTRA-GLOBAL

Prefix Lists

IPv4 Prefixes (65 total)

  • 62.134.0.0/16 (65 536 addresses)
  • 62.180.0.0/16 (65 536 addresses)
  • 195.100.0.0/16 (65 536 addresses)
  • 195.163.0.0/16 (65 536 addresses)
  • 206.73.0.0/16 (65 536 addresses)
  • 213.15.0.0/16 (65 536 addresses)
  • 62.5.0.0/17 (32 768 addresses)
  • 62.102.0.0/17 (32 768 addresses)
  • 166.49.128.0/17 (32 768 addresses)
  • 62.173.192.0/18 (16 384 addresses)
  • 212.162.192.0/18 (16 384 addresses)
  • 213.194.0.0/18 (16 384 addresses)
  • 213.236.64.0/18 (16 384 addresses)
  • 31.95.96.0/19 (8 192 addresses)
  • 82.138.160.0/19 (8 192 addresses)
  • 82.150.0.0/19 (8 192 addresses)
  • 194.213.64.0/19 (8 192 addresses)
  • 195.90.64.0/19 (8 192 addresses)
  • 195.182.96.0/19 (8 192 addresses)
  • 212.8.160.0/19 (8 192 addresses)
  • 212.21.192.0/19 (8 192 addresses)
  • 212.31.192.0/19 (8 192 addresses)
  • 212.41.128.0/19 (8 192 addresses)
  • 212.108.0.0/19 (8 192 addresses)
  • 212.127.0.0/19 (8 192 addresses)
  • 213.137.160.0/19 (8 192 addresses)
  • 31.95.16.0/20 (4 096 addresses)
  • 80.255.160.0/20 (4 096 addresses)
  • 132.244.64.0/20 (4 096 addresses)
  • 195.99.64.0/20 (4 096 addresses)
  • 31.95.0.0/21 (2 048 addresses)
  • 31.95.48.0/21 (2 048 addresses)
  • 62.172.0.0/21 (2 048 addresses)
  • 194.74.80.0/21 (2 048 addresses)
  • 46.248.8.0/22 (1 024 addresses)
  • 185.94.0.0/22 (1 024 addresses)
  • 195.171.36.0/22 (1 024 addresses)
  • 31.95.218.0/23 (512 addresses)
  • 136.238.84.0/23 (512 addresses)
  • 193.58.130.0/23 (512 addresses)
  • 194.33.54.0/23 (512 addresses)
  • 195.60.182.0/23 (512 addresses)
  • 203.158.76.0/23 (512 addresses)
  • 132.244.240.0/24 (256 addresses)
  • 136.238.224.0/24 (256 addresses)
  • 185.249.4.0/24 (256 addresses)
  • 192.109.52.0/24 (256 addresses)
  • 193.202.26.0/24 (256 addresses)
  • 194.33.53.0/24 (256 addresses)
  • 194.50.160.0/24 (256 addresses)

IPv6 Prefixes (14 total)

  • 2a00:2000::/23
  • 2a00:2200::/24
  • 2a00:2300::/25
  • 2a0c:7c80::/29
  • 2a0c:8480::/30
  • 2001:740::/32