AS4991 Cogent Communications, LLC
AS4991 (COGENT-4991-4994) is registered to Cogent Communications, LLC in US. It originates 1 prefix in the global routing table.
Who holds AS4991
Names from RIPE NCC’s daily list of every allocated AS number. The ASN lookup fetches the full WHOIS record live.
What AS4991 announces
Prefixes originated by AS4991 in the RouteViews table (refreshed every four hours), each checked against the RPKI (every ten minutes) and the IRR (daily).
Announced prefixes
Each opens its own page: who announces it, the paths our collectors see, its ROAs and route objects.
Who AS4991 is reached through
The AS just before AS4991 in the paths our looking glass collectors hold, for 1 of its prefixes. Usually a transit provider, sometimes a peer. The number is how many of those prefixes it was seen on.
Routing registry objects
From the mirrored IRR databases (RADB, the five RIRs and more). Look it up live.