大约在这段时间内：
Fri Jul 3 19:31:00 UTC 2020
大约在这个时候：
Fri Jul 3 20:31:00 UTC 2020
我无法从 安装任何软件包us.archive.ubuntu.com，但除此之外我的连接正常。
$ sudo apt install --reinstall k4dirstat
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 230 kB of archives.
After this operation, 0 B of additional disk space will be used.
Err:1 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 k4dirstat amd64 3.1.3-1
Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable)
E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/universe/k/k4dirstat/k4dirstat_3.1.3-1_amd64.deb Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
停机时间已经超过一小时，但 Canonical 状态页面上却没有任何内容。
2020 年 7 月 3 日
今天没有报告任何事件
我无法再复制该问题，但这是中断期间几个命令的输出：
$ ping -c 5 us.archive.ubuntu.com
connect: Network is unreachable
$ host -v us.archive.ubuntu.com
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6730
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
Received 39 bytes from 127.0.0.53#53 in 0 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7987
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN AAAA
;; ANSWER SECTION:
us.archive.ubuntu.com. 60 IN AAAA 2001:67c:1562::15
us.archive.ubuntu.com. 60 IN AAAA 2001:67c:1562::18
Received 95 bytes from 127.0.0.53#53 in 25 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31711
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN MX
Received 39 bytes from 127.0.0.53#53 in 23 ms
$ dig us.archive.ubuntu.com
; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> us.archive.ubuntu.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18603
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Jul 03 16:10:01 EDT 2020
;; MSG SIZE rcvd: 50
$ systemd-resolve us.archive.ubuntu.com
us.archive.ubuntu.com: resolve call failed: 'us.archive.ubuntu.com' does not have any RR of the requested type
$ nslookup us.archive.ubuntu.com
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::15
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::18
$ wget --no-proxy --spider us.archive.ubuntu.com
Spider mode enabled. Check if remote file exists.
--2020-07-03 16:11:52-- http://us.archive.ubuntu.com/
Resolving us.archive.ubuntu.com (us.archive.ubuntu.com)... 2001:67c:1562::15, 2001:67c:1562::18
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|2001:67c:1562::15|:80... failed: Network is unreachable.
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|2001:67c:1562::18|:80... failed: Network is unreachable.
中断后：
$ ping -c 5 us.archive.ubuntu.com
PING ubuntu.com (91.189.88.180) 56(84) bytes of data.
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=1 ttl=56 time=75.1 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=2 ttl=56 time=129 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=3 ttl=56 time=82.9 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=4 ttl=56 time=76.4 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=5 ttl=56 time=79.7 ms
--- ubuntu.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4003ms
rtt min/avg/max/mdev = 75.176/88.823/129.794/20.661 ms
$ host -v us.archive.ubuntu.com
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20309
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; ANSWER SECTION:
us.archive.ubuntu.com. 3 IN A 91.189.91.39
us.archive.ubuntu.com. 3 IN A 91.189.91.38
Received 71 bytes from 127.0.0.53#53 in 2 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15398
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN AAAA
;; ANSWER SECTION:
us.archive.ubuntu.com. 4 IN AAAA 2001:67c:1562::18
us.archive.ubuntu.com. 4 IN AAAA 2001:67c:1562::15
Received 95 bytes from 127.0.0.53#53 in 1 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8865
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN MX
Received 39 bytes from 127.0.0.53#53 in 86 ms
$ dig us.archive.ubuntu.com
; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> us.archive.ubuntu.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37941
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; ANSWER SECTION:
us.archive.ubuntu.com. 17 IN A 91.189.91.39
us.archive.ubuntu.com. 17 IN A 91.189.91.38
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Jul 03 16:53:02 EDT 2020
;; MSG SIZE rcvd: 82
$ systemd-resolve us.archive.ubuntu.com
us.archive.ubuntu.com: 91.189.91.38
91.189.91.39
-- Information acquired via protocol DNS in 84.5ms.
-- Data is authenticated: no
$ nslookup us.archive.ubuntu.com
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: us.archive.ubuntu.com
Address: 91.189.91.39
Name: us.archive.ubuntu.com
Address: 91.189.91.38
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::18
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::15
$ wget --no-proxy --spider us.archive.ubuntu.com
Spider mode enabled. Check if remote file exists.
--2020-07-03 16:52:41-- http://us.archive.ubuntu.com/
Resolving us.archive.ubuntu.com (us.archive.ubuntu.com)... 91.189.91.39, 91.189.91.38, 2001:67c:1562::18, ...
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|91.189.91.39|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Remote file exists and could contain further links,
but recursion is disabled -- not retrieving.
我的问题：
这是由于 Ubuntu 服务器停机、我的 ISP 出现某种瞬态 DNS 问题，还是其他原因造成的？
如果将来出现中断，我应该如何区分 Ubuntu 服务器停机和 DNS 问题？
有没有什么地方我可以去检查子域名的状态
us.archive.ubuntu.com？