Fastly CDN causing slow loading of images from X(Twitter)

A slow connection to the X (Twitter) image server (pbs.twimg.com) has been occurring in Japan for an extended period of time (at least two months).
Several users have reported that they are connecting from an IP in Japan, but the connection is responding to a route through an overseas network, resulting in large delays.
I have had a simple script that traceroute the Fastly endpoint (dualstack.twimg.twitter.map.fastly.net) pointed to by the CNAME of pbs.twimg.com running in cron for several days. As a result, endpoints that bypassed overseas from Japan were responded to at a probability of approximately 40% to 50%.
The following is an example. This traffic somehow jumped from AS2516 to AS1299 and then to AS54113, even though AS2516 and AS54113 are peered.

========== Sun Feb 9 12:00:07 JST 2025 ==========
Resolved pbs.twimg.com to IPv4: 146.75.40.159
Running traceroute (IPv4) to 146.75.40.159…
traceroute to 146.75.40.159 (146.75.40.159), 30 hops max, 60 byte packets
1 192.168.0.1 (192.168.0.1) [*] 0.267 ms 0.238 ms *
2 27.85.199.142 (27.85.199.142) [AS2516] 12.158 ms * *
3 27.85.199.141 (27.85.199.141) [AS2516] 12.734 ms * *
4 27.86.120.157 (27.86.120.157) [AS2516] 13.402 ms * *
5 * * *
6 106.187.13.26 (106.187.13.26) [AS2516] 111.857 ms * *
7 111.87.3.234 (111.87.3.234) [AS2516] 118.639 ms * *
8 sjo-b23-link.ip.twelve99.net (62.115.180.213) [AS1299] 122.606 ms * *
9 sea-b1-link.ip.twelve99.net (62.115.132.153) [AS1299] 131.440 ms * *
10 fastly-ic-370067.ip.twelve99-cust.net (213.155.141.201) [AS1299] 142.655 ms * *
11 * 146.75.40.159 (146.75.40.159) [AS54113] 142.481 ms *

I posted a post on X (Twitter) in Japanese describing this situation. The post received 1600 reposts, and the quoted post showed that many users were suffering from the same phenomenon.
I do not believe this is an issue caused by a specific provider or cache DNS.

https://x.com/1nagawa/status/1884072241740251188

Dear Fastly, Can you please help us solve this phenomenon that has been plaguing many of our users for a long time? Also. Is there anything I can do to help?

Please send an email to support@fastly.com and they’ll work with you to collect details.

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