The reader in Lagos routed to Virginia instead of London

The reader in Lagos routed to Virginia instead of London

A media site noticed West-African readers had 600ms+ latency while the CDN claimed global coverage. The anycast routing was sending Lagos traffic across the Atlantic to Virginia.

We debugged the geo-routing path:

— Ran traceroutes and RUM from Lagos: confirmed traffic terminated in US-East, not the EU or African POP
— Found the reader's ISP peered poorly and announced routes that pulled traffic west
— Worked with the CDN to verify a Lagos and a London POP were both eligible for that ISP
— Confirmed the origin-fetch path also went the long way and fixed the shield POP choice
— Re-measured from the same ISP after route adjustments

Lagos p75 dropped from 610ms to 180ms once traffic stayed regional. Anycast isn't magic — peering and ISP route announcements decide the real path. Measure from the actual ISP, not a clean datacenter, before you trust the coverage map.

The number that mattered: 430ms cut for an entire region by fixing one routing path.