$ query “AS3561” --type=asn → 1 result(s)

AS3561 — CENTURYLINK-LEGACY-SAVVIS

CenturyLink Communications LLC

AS3561 is a mid-size transit provider registered to CenturyLink Communications LLC, established in the United States in 1998. The network announces an impressive 8.9 million IPv4 addresses, including a /13. Supports IPv6.

  • Top 5% — Top 5% of all autonomous systems by reach and degree
  • Pioneer — Registered before the year 2000

Basic Information

Country
🇺🇸 United States
Category
Hosting
Network Role
Mid-size Transit
Data Origin
Authoritative — Metadata from authoritative RIR registry (ARIN, RIPE, APNIC, etc.)
Registered
October 07, 1998
Last Changed
March 04, 2026
Last Seen
March 05, 2026

Prefix Summary

IPv4 Prefixes (raw / aggregated)
659 / 343
IPv6 Prefixes (raw / aggregated)
2 / 2
IPv4 Addresses
8 920 320
Largest IPv4 Prefix
/13 (524 288 addresses)
Largest IPv6 Prefix
/46
Geolocated Countries
🇺🇸 US (967 IPs), 🇨🇦 CA (171 IPs), 🇭🇰 HK (25 IPs), 🇬🇧 GB, 🇯🇵 JP, 🇧🇲 BM, 🇸🇬 SG, 🇷🇴 RO, 🇵🇰 PK, 🇫🇷 FR, 🇩🇪 DE, 🇦🇺 AU, 🇳🇱 NL, 🇨🇭 CH and 22 more
Prefix Changed
March 04, 2026

Reputation

Reputation
Good — 2 flagged IPs out of 8 920 320 total (0.00%)

Connectivity Summary

Upstream Providers
3 upstream autonomous systems providing transit
Peers
2 autonomous systems exchanging traffic without transit fees
Downstream Customers
57 downstream autonomous systems buying transit
Degree
64 unique BGP neighbors (providers + customers + peers)
Reach
58 — customer cone size measuring network influence
Degree Rank
#2 509
Reach Rank
#1 420

Upstream Providers (3)

  • AS3356 — LEVEL3 (Tier-1 transit)
  • AS209 — CENTURYLINK-US-LEGACY-QWEST (Tier-1 transit)
  • AS3910 — CENTURYLINK-EUROPE-LEGACY-QWEST

Prefix Lists

IPv4 Prefixes (659 total)

  • 208.144.0.0/13 (524 288 addresses)
  • 64.240.0.0/14 (262 144 addresses)
  • 206.100.0.0/14 (262 144 addresses)
  • 208.140.0.0/14 (262 144 addresses)
  • 208.152.0.0/14 (262 144 addresses)
  • 216.32.0.0/14 (262 144 addresses)
  • 216.88.0.0/14 (262 144 addresses)
  • 63.128.0.0/15 (131 072 addresses)
  • 66.100.0.0/15 (131 072 addresses)
  • 204.70.0.0/15 (131 072 addresses)
  • 205.138.0.0/15 (131 072 addresses)
  • 205.218.0.0/15 (131 072 addresses)
  • 206.26.0.0/15 (131 072 addresses)
  • 206.30.0.0/15 (131 072 addresses)
  • 206.156.0.0/15 (131 072 addresses)
  • 207.0.0.0/15 (131 072 addresses)
  • 207.48.0.0/15 (131 072 addresses)
  • 208.128.0.0/15 (131 072 addresses)
  • 208.134.0.0/15 (131 072 addresses)
  • 208.136.0.0/15 (131 072 addresses)
  • 208.158.0.0/15 (131 072 addresses)
  • 208.160.0.0/15 (131 072 addresses)
  • 208.164.0.0/15 (131 072 addresses)
  • 208.170.0.0/15 (131 072 addresses)
  • 63.137.0.0/16 (65 536 addresses)
  • 64.14.0.0/16 (65 536 addresses)
  • 165.193.0.0/16 (65 536 addresses)
  • 167.215.0.0/16 (65 536 addresses)
  • 204.189.0.0/16 (65 536 addresses)
  • 205.136.0.0/16 (65 536 addresses)
  • 205.216.0.0/16 (65 536 addresses)
  • 206.25.0.0/16 (65 536 addresses)
  • 206.79.0.0/16 (65 536 addresses)
  • 206.98.0.0/16 (65 536 addresses)
  • 206.129.0.0/16 (65 536 addresses)
  • 206.142.0.0/16 (65 536 addresses)
  • 206.150.0.0/16 (65 536 addresses)
  • 206.152.0.0/16 (65 536 addresses)
  • 206.155.0.0/16 (65 536 addresses)
  • 207.3.0.0/16 (65 536 addresses)
  • 207.51.0.0/16 (65 536 addresses)
  • 207.82.0.0/16 (65 536 addresses)
  • 207.124.0.0/16 (65 536 addresses)
  • 207.149.0.0/16 (65 536 addresses)
  • 208.130.0.0/16 (65 536 addresses)
  • 208.133.0.0/16 (65 536 addresses)
  • 208.139.0.0/16 (65 536 addresses)
  • 208.156.0.0/16 (65 536 addresses)
  • 208.162.0.0/16 (65 536 addresses)
  • 208.172.0.0/16 (65 536 addresses)

IPv6 Prefixes (2 total)

  • 2001:460:78::/46
  • 2001:460:100::/46