几天来，apt-get 一直未能从德国存档镜像 de.archive.ubuntu.com 检索两个文件：
Hit http://de.archive.ubuntu.com saucy/universe amd64 Packages
Hit http://de.archive.ubuntu.com saucy/multiverse amd64 Packages
[...]
Err http://de.archive.ubuntu.com saucy/universe i386 Packages
406 Not Acceptable [IP: 141.30.13.20 80]
Err http://de.archive.ubuntu.com saucy/multiverse i386 Packages
406 Not Acceptable [IP: 141.30.13.20 80]
[...]
W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/saucy/universe/binary-i386/Packages 406 Not Acceptable [IP: 141.30.13.20 80]
W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/saucy/multiverse/binary-i386/Packages 406 Not Acceptable [IP: 141.30.13.20 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
我应该向谁报告这个问题？
我正在KVM 主机上测试Ubuntu 18.04 LTS 云映像 (20180426.2)。有一个 DHCP v4 服务器正在运行，但不支持 IPv6。启动云映像时，它不会获得 IPv4 地址。服务 systemd-networkd-wait-online 启动失败：
root@ubuntu:~# systemctl status systemd-networkd-wait-online.service
? systemd-networkd-wait-online.service - Wait for Network to be Configured
Loaded: loaded (/lib/systemd/system/systemd-networkd-wait-online.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Mon 2018-04-30 11:08:47 UTC; 12min ago
Docs: man:systemd-networkd-wait-online.service(8)
Process: 669 ExecStart=/lib/systemd/systemd-networkd-wait-online (code=exited, status=1/FAILURE)
Main PID: 669 (code=exited, status=1/FAILURE)
Apr 30 11:06:47 ubuntu systemd[1]: Starting Wait for Network to be Configured...
Apr 30 11:08:47 ubuntu systemd-networkd-wait-online[669]: Event loop failed: Connection …