mirrors.bfsu.edu.cn prober timeout but it is up and reachable

[Aron Xu]

mirrors.bfsu.edu.cn prober timeout but it is up and reachable (the prober log shows HEAD request timeout), I'm not sure whether it's a prober problem or just the network route from prober to mirror has some problem.

$ curl -I https://mirrors.bfsu.edu.cn/ubuntu/dists/kinetic/main/binary-i386/Packages.gz
HTTP/2 200
server: nginx/1.14.2
date: Thu, 22 Sep 2022 10:00:57 GMT
content-type: application/octet-stream
content-length: 1332573
last-modified: Thu, 22 Sep 2022 09:11:00 GMT
etag: "632c26a4-14555d"
accept-ranges: bytes

From the mirror server, traceroute to one of the known prober IP (185.125.188.85):
$ mtr -c 10 -nr 185.125.188.85
Start: 2022-09-22T18:06:35+0800
HOST: echo Loss% Snt Last Avg Best Wrst StDev
  3.|-- 60.247.124.165 0.0% 10 1.8 1.6 1.3 1.9 0.2
  4.|-- 60.247.124.249 90.0% 10 2.5 2.5 2.5 2.5 0.0
  5.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
  6.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
  7.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
  8.|-- ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
  9.|-- 217.163.47.129 40.0% 10 150.2 150.2 150.1 150.3 0.1
 10.|-- 4.69.166.2 0.0% 10 150.3 153.0 150.3 160.9 4.1
 11.|-- 194.88.86.2 0.0% 10 247.9 247.9 247.8 248.0 0.0
 12.|-- 185.125.188.85 0.0% 10 247.4 247.4 247.4 247.7 0.1

[Guruprasad (lgp171188)]

Hi,

We are investigating this and will get back to you soon.

[Colin Watson (cjwatson)]

It's not a prober problem. I tried a simple `curl -v https://mirrors.bfsu.edu.cn/ubuntu/dists/kinetic/InRelease` via the relevant HTTPS proxy from one of our non-production machines and it never returned a response.

[Aron Xu (happyaron)]

It could be a network issue with Canonical's server network, the mirror works when testing from AWS EC2 instance. Would you mind to help check further?

[Colin Watson (cjwatson)]

Launchpad staff aren't directly equipped to debug routing issues, but I filed a ticket with our sysadmins (https://portal.admin.canonical.com/C153634 - you won't be able to see that, but Canonical employees can) to investigate further.