BGP routing loop — Fastly prefix 199.232.252.0/22 unreachable from Fresno market

Requesting Tier 2 / Network Engineering. This is NOT a modem or in-home issue — please do not dispatch a technician or reset my gateway. Account and WAN IP available via DM.

Market: Fresno, CA | Observed: 2026-07-29 15:47 PDT | Duration: ~3 weeks

PROBLEM

Fastly prefix 199.232.252.0/22 (origin AS54113) is unreachable from my connection. TCP connect fails in ~21ms with EHOSTUNREACH. Dead across all four /24s (199.232.252-255.x); 199.232.251.x and below are fine.

Traceroute loops between two of your own routers and never reaches your backbone:

6  ae-501-ar01.fresno.ca.ccal.comcast.net      (96.216.129.182)
7  be-501-arsc1.sacramento.ca.ccal.comcast.net (96.216.129.193)
8  ae-501-ar01.fresno.ca.ccal.comcast.net      (96.216.129.182)
9  be-501-arsc1.sacramento.ca.ccal.comcast.net (96.216.129.193)
10  ae-501-ar01.fresno.ca.ccal.comcast.net      (96.216.129.182)

CONTROL — a different Fastly prefix from the same source exits normally:

traceroute 151.101.196.158
6  be-42-arsc1.sacramento.ca.ccal.comcast.net   (96.110.62.193)
6  be-36421-cs02.sunnyvale.ca.ibone.comcast.net (96.110.41.101)  <- backbone

NOT A DESTINATION PROBLEM

199.232.252.0/22 is announced by AS54113 and visible to 330 of 330 RIPE RIS peers as of 2026-07-29 16:00 UTC, continuously announced since 2020-09-25. The prefix is globally reachable. Comcast is the only network that cannot route to it.

CUSTOMER IMPACT

Comcast's resolver hands Fresno-market customers addresses inside this prefix for video.twimg.com, so all X/Twitter video playback fails in every browser. The error X displays is generic, so affected customers blame X rather than reporting it. Third-party DNS works around it but does not fix the route.

ASK

Please correct the next-hop / route for 199.232.252.0/22 in the Fresno market so it reaches the backbone as sibling Fastly prefixes do.