AS13205
British Telecommunications Limited
Reputation · trust score
A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.
- Baseline (neutral) 65
- Isp allocation +5
- Trust score 70 / 100
Experimental · trust-vectors model v1.2.1 — a transparent heuristic, not a definitive verdict. How it works →
Top CIDR ranges
BGP Announced Prefixes
Live BGP anomalies →Prefixes AS13205 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.
| Prefix | Announcement samples | Last seen |
|---|---|---|
| 78.109.10.0/24 | 14,692 | 2026-10-18 10:48:29 |
| 78.109.9.0/24 | 14,602 | 2026-10-18 10:47:40 |
| 78.109.11.0/24 | 14,576 | 2026-10-18 10:48:29 |
| 78.109.0.0/20 | 14,553 | 2026-10-18 10:48:29 |
| 78.109.6.0/24 | 14,520 | 2026-10-18 10:47:40 |
| 78.109.5.0/24 | 14,434 | 2026-10-18 10:47:40 |
| 78.109.0.0/24 | 14,345 | 2026-10-18 10:47:40 |
| 217.140.12.0/22 | 14,196 | 2026-10-18 10:48:29 |
| 31.11.56.0/23 | 14,122 | 2026-10-18 10:47:40 |
| 217.140.13.0/24 | 14,119 | 2026-10-18 10:47:40 |
| 217.140.12.0/24 | 14,105 | 2026-10-18 10:47:40 |
| 217.140.0.0/20 | 13,976 | 2026-10-18 10:48:29 |
| 78.109.7.0/24 | 13,944 | 2026-10-18 10:47:00 |
| 217.140.32.0/19 | 13,852 | 2026-10-18 10:06:43 |
| 137.213.239.0/24 | 8,674 | 2026-08-12 21:22:25 |
| 137.213.252.0/23 | 8,493 | 2026-08-12 21:22:25 |
Frequently Asked Questions
What is AS13205?
AS13205 is an Autonomous System Number assigned to British Telecommunications Limited. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).
How many IP addresses does AS13205 announce?
AS13205 announces 16.9K IPv4 addresses distributed across 4 routed CIDR prefixes. The network is registered in United Kingdom.
Who operates AS13205?
AS13205 is operated by British Telecommunications Limited. The organization is based in United Kingdom. You can view all IP ranges and related ASNs on the organization page.
What country is AS13205 registered in?
AS13205 is registered in United Kingdom. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.
