Our staff/customers are intermittently seeing 520 Unknown Errors from Cloudflare when using Telstra fixed line connections in Australia, when those requests are routed through the SIN COLO. We don’t see these errors with other providers, such as Aussie Broadband, just Telstra, at this stage.
I noted that Aussie Broadband seems to always route through SYD COLO, whereas Telstra is always routing through SIN COLO.
I’ve checked the web server and the requests are resolving just fine, status 200, quickly, no problems at the server end. Not seeing anything in the error log. The server is sitting in Sydney in AWS EC2, not overloaded, plenty of bandwidth, so just trying to eliminate network issues here. I just can’t find an error at the server end at all.
Is anyone else seeing anything similar or have any suggestions at all? I’ve hit a dead end on troubleshooting and suspect it might be a network/routing issues between Cloudflare SIN and AWS SYD.
For anyone internal to CF that may see this the details of the request are below:
Ray ID: 688a7d0318e33c64
Time: 2021-09-02 23:23:50 UTC