United Kingdom · ISP
AS2856
British Telecommunications PLC
ISP RIPE NCC BT-UK-AS
BT Retail plus the Openreach wholesale estate, so a large fraction of UK broadband exits here regardless of which brand the customer pays.
ISP — Residential eyeball network. Addresses here look like customers, because they are.
- Announced prefixes
- 6
- 5 IPv4 · 1 IPv6
- IPv4 addresses
- 8.7M
- across the blocks listed below
- Largest block
- /10
- smallest prefix length announced
- Registry
- RIPE NCC
- BT-UK-AS
01 Ranges
Announced ranges
The blocks AS2856 advertises to the rest of the internet in this snapshot. A production routing table carries more — large carriers de-aggregate for traffic engineering — so treat the totals as a floor.
Matched in your browser against the 6 blocks below. Nothing is sent anywhere.
IPv4 — 5 blocks
| Prefix | First address | Last address | Addresses |
|---|---|---|---|
| 51.148.0.0/14 | 51.148.0.0 | 51.151.255.255 | 262,144 |
| 81.128.0.0/11 | 81.128.0.0 | 81.159.255.255 | 2,097,152 |
| 86.128.0.0/10 | 86.128.0.0 | 86.191.255.255 | 4,194,304 |
| 109.144.0.0/12 | 109.144.0.0 | 109.159.255.255 | 1,048,576 |
| 217.32.0.0/12 | 217.32.0.0 | 217.47.255.255 | 1,048,576 |
IPv6 — 1 blocks
| Prefix | First address | Last address | Addresses |
|---|---|---|---|
| 2a00:2380::/32 | 2a00:2380:: | 2a00:2380:ffff:ffff:ffff:ffff:ffff:ffff | 2^96 |