AS21547FirstLight Networks, LLC
United StatesRegistryARINAs of 27th September 2026, AS21547 (FirstLight Networks, LLC), a network registered in the United States with ARIN, originates 57 IPv4 prefixes covering 91.9k addresses and 5 IPv6 prefixes. By IPv4 address space that makes it the 2,527th-largest of the 79,523 networks we see originating IPv4, and the 810th-largest of 18,427 in the United States. It is seen behind 1 upstream network, most often AS13536 (FirstLight Networks, LLC), and in front of 5 downstream networks. 42% of its announcements have a valid RPKI ROA; 1 is RPKI-invalid. 94% of its routes reach at least 90% of full-feed peers, and 3 prefixes are also originated by another network.
At a glance
IPv4 prefixes
IPv6 prefixes
IPv4 addresses
IPv6 /64s
Upstream graph
The networks AS21547 is seen behind, one and two hops out, drawn from real AS paths.
Networks observed one and two hops upstream of AS21547 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.
Neighbouring networks
12
adjacent networks
- Upstreams
- 18%
- Peers
- 650%
- Downstreams
- 542%
Networks carrying this one's traffic toward the rest of the internet.
| Network | Country | Relationship | Paths | Vantage pts |
|---|---|---|---|---|
| AS13536FirstLight Networks, LLC | US | Peer | 5,120 | 145 |
Prefixes
All 62The largest blocks AS21547 originates, widest first.
| Prefix | Addresses | Visibility |
|---|---|---|
| 64.140.192.0/18 | 16.4k | 80/81 |
| 64.140.224.0/19 | 8.2k | 80/81 |
| 66.186.160.0/19 | 8.2k | 81/81 |
| 66.231.192.0/19 | 8.2k | 81/81 |
| 69.49.128.0/19 | 8.2k | 81/81 |
| 72.12.64.0/19 | 8.2k | 81/81 |
| 72.55.224.0/19 | 8.2k | 81/81 |
| 69.168.0.0/20 | 4.1k | 81/81 |
| 74.220.224.0/20 | 4.1k | 81/81 |
| 63.127.192.0/21 | 2k | 81/81 |
Routing health
How AS21547's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.
RPKI origin validation
- Valid41.9%26
- Invalid1.6%1
- No ROA56.5%35
Propagation
- Globally propagated90% of full-feed peers or more93.5%58
- Partially propagated40% to 90%3.2%2
- Seen by few peersUnder 40%3.2%2
Prefix sizes
IPv4 — 57 prefixes
IPv6 — 5 prefixes
- /324.3B × /6440.0%2
- /4865.5k × /6460.0%3
Recent changes
Announcements that started or stopped since 28th Aug 2026.
- Withdrawn66.231.207.0/2421st Sept 2026
Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.