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one honk maybe more

benjojo posted 22 Oct 2023 13:40 +0000

Don't get too excited if you see indications of Cogent and HE peering with each other on bgp.tools!

This appears to be a interesting BGP AS path manipulation fault ( a mistake I assume )

This appears to be caused by 2a0f:85c1:270::/44, the true path appears to be something like.

AS6939 (HE) -> AS12129 (123.Net, Inc) -> AS13737 (INCX Global) -> AS174 (Cogent) -> AS22439 (Perfect International)

However it would seem that 123.Net has stripped out itself and INCX Global, before leaking a Cogent path to HE. Meaning the path looks like

AS6939 (HE) -> AS174 (Cogent) -> AS22439 (Perfect International)

Weird that HE accepted the route, but noc@he.net have been informed regardless :)

A screenshot of bgp.tools's page for AS6939 also known as Hurricane Electric, showing AS174 also known as Cogent peering on IPv6