我一直在排查我的 Apache 服务器，但一直没有成功。当我输入 URL 时，我得到这样的信息：浏览器无法打开页面，因为服务器没有响应。
当我在终端中尝试 curl 时，它超时了。
curl 139.162.193.10
curl: (7) Failed to connect to 139.162.193.10 port 80: Operation timed out
traceroute 的输出：
➜ ~ traceroute www.wearenaughtypixel.co.uk
traceroute to www.wearenaughtypixel.co.uk (139.162.193.10), 64 hops max, 52 byte packets
1 bthomehub (192.168.1.254) 72.481 ms 6.291 ms 9.498 ms
2 * * *
3 * * *
4 31.55.186.176 (31.55.186.176) 10.121 ms 11.499 ms 16.226 ms
5 core4-hu0-16-0-3.faraday.ukcore.bt.net (195.99.127.206) 13.949 ms
core4-hu0-8-0-5.faraday.ukcore.bt.net (195.99.127.56) 14.247 ms
core3-hu0-14-0-1.faraday.ukcore.bt.net (195.99.127.42) 25.327 ms
6 213.137.183.32 (213.137.183.32) 14.876 ms
213.137.183.96 (213.137.183.96) 14.341 ms
213.137.183.38 (213.137.183.38) 13.204 ms
7 82.112.115.185 (82.112.115.185) 12.984 ms 11.453 ms
ldn-b3-link.telia.net (213.248.67.97) 9.699 ms
8 ldn-bb3-link.telia.net (62.115.117.20) 12.696 ms
ae-1.r03.londen05.uk.bb.gin.ntt.net (129.250.6.230) 10.453 ms 12.211 ms
9 ldn-b4-link.telia.net (62.115.119.145) 10.314 ms
ae-2.r04.londen05.uk.bb.gin.ntt.net (129.250.6.9) 10.492 ms 14.466 ms
10 linode-ic-318542-ldn-b3.c.telia.net (62.115.41.65) 10.500 ms
ae-0.r24.londen12.uk.bb.gin.ntt.net (129.250.4.140) 14.885 ms 12.536 ms
11 switch-lon1.linode.com (109.74.207.5) 11.348 ms
109.74.207.13 (109.74.207.13) 14.566 ms
ae-6.r00.londen10.uk.bb.gin.ntt.net (129.250.4.21) 10.792 ms
12 * 83.217.238.86 (83.217.238.86) 26.789 ms 17.123 ms
13 * * gw-h10.linode.com (109.74.207.1) 20.029 ms
14 * * *
15 * * *
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
31 * * *
32 * * *
33 * * *
34 * * *
35 * * *
36 * * *
37 * * *
38 * * *
39 * * *
40 * * *
41 * * *
42 * * *
43 * * *
44 * * *
45 * * *
46 * * *
47 * * *
48 * * *
49 * * *
50 * * *
51 * * *
52 * * *
53 * * *
54 * * *
55 * * *
56 * * *
57 * * *
58 * * *
59 * * *
60 * * *
61 * * *
62 * * *
63 * * *
64 * * *
网络状态
sudo netstat -ntlup
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 23688/mysqld
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 30274/sshd
tcp6 0 0 :::80 :::* LISTEN 1891/apache2
systemctl 状态 apache2
$ systemctl status apache2
● apache2.service - LSB: Apache2 web server
Loaded: loaded (/etc/init.d/apache2; bad; vendor preset: enabled)
Drop-In: /lib/systemd/system/apache2.service.d
└─apache2-systemd.conf
Active: active (running) since Sat 2016-11-12 01:06:18 GMT; 19h ago
Docs: man:systemd-sysv-generator(8)
Process: 1848 ExecStop=/etc/init.d/apache2 stop (code=exited, status=0/SUCCESS)
Process: 2880 ExecReload=/etc/init.d/apache2 reload (code=exited, status=0/SUCCESS)
Process: 1872 ExecStart=/etc/init.d/apache2 start (code=exited, status=0/SUCCESS)
CGroup: /system.slice/apache2.service
├─1891 /usr/sbin/apache2 -k start
├─2912 /usr/sbin/apache2 -k start
├─2913 /usr/sbin/apache2 -k start
├─2916 /usr/sbin/apache2 -k start
├─2917 /usr/sbin/apache2 -k start
├─3118 /usr/sbin/apache2 -k start
├─3119 /usr/sbin/apache2 -k start
├─3120 /usr/sbin/apache2 -k start
├─3121 /usr/sbin/apache2 -k start
├─3122 /usr/sbin/apache2 -k start
├─3123 /usr/sbin/apache2 -k start
├─3124 /usr/sbin/apache2 -k start
├─3125 /usr/sbin/apache2 -k start
├─3126 /usr/sbin/apache2 -k start
├─3127 /usr/sbin/apache2 -k start
├─3128 /usr/sbin/apache2 -k start
├─3129 /usr/sbin/apache2 -k start
├─3130 /usr/sbin/apache2 -k start
为了解决这个问题，我应该研究最有可能的问题是什么？
我正在使用简单防火墙
$ sudo ufw status
[sudo] password for oliver:
Status: active
To Action From
-- ------ ----
22 ALLOW Anywhere
22 (v6) ALLOW Anywhere (v6)
$ sudo iptables -vL 输出：
$ sudo iptables -vL
Chain INPUT (policy DROP 18 packets, 1291 bytes)
pkts bytes target prot opt in out source destination
163K 17M f2b-sshd tcp -- any any anywhere anywhere multiport dports ssh
138K 14M ufw-before-logging-input all -- any any anywhere anywhere
138K 14M ufw-before-input all -- any any anywhere anywhere
33043 1544K ufw-after-input all -- any any anywhere anywhere
32969 1540K ufw-after-logging-input all -- any any anywhere anywhere
32969 1540K ufw-reject-input all -- any any anywhere anywhere
32969 1540K ufw-track-input all -- any any anywhere anywhere
Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ufw-before-logging-forward all -- any any anywhere anywhere
0 0 ufw-before-forward all -- any any anywhere anywhere
0 0 ufw-after-forward all -- any any anywhere anywhere
0 0 ufw-after-logging-forward all -- any any anywhere anywhere
0 0 ufw-reject-forward all -- any any anywhere anywhere
0 0 ufw-track-forward all -- any any anywhere anywhere
Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
190K 32M ufw-before-logging-output all -- any any anywhere anywhere
190K 32M ufw-before-output all -- any any anywhere anywhere
1359 123K ufw-after-output all -- any any anywhere anywhere
1359 123K ufw-after-logging-output all -- any any anywhere anywhere
1359 123K ufw-reject-output all -- any any anywhere anywhere
1359 123K ufw-track-output all -- any any anywhere anywhere
Chain f2b-sshd (1 references)
pkts bytes target prot opt in out source destination
63 4932 REJECT all -- any any 116.31.116.41 anywhere reject-with icmp-port-unreachable
126K 15M RETURN all -- any any anywhere anywhere
Chain ufw-after-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-input (1 references)
pkts bytes target prot opt in out source destination
31 2418 ufw-skip-to-policy-input udp -- any any anywhere anywhere udp dpt:netbios-ns
0 0 ufw-skip-to-policy-input udp -- any any anywhere anywhere udp dpt:netbios-dgm
7 336 ufw-skip-to-policy-input tcp -- any any anywhere anywhere tcp dpt:netbios-ssn
36 1776 ufw-skip-to-policy-input tcp -- any any anywhere anywhere tcp dpt:microsoft-ds
0 0 ufw-skip-to-policy-input udp -- any any anywhere anywhere udp dpt:bootps
0 0 ufw-skip-to-policy-input udp -- any any anywhere anywhere udp dpt:bootpc
0 0 ufw-skip-to-policy-input all -- any any anywhere anywhere ADDRTYPE match dst-type BROADCAST
Chain ufw-after-logging-forward (1 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- any any anywhere anywhere limit: avg 3/min burst 10 LOG level warning prefix "[UFW BLOCK] "
Chain ufw-after-logging-input (1 references)
pkts bytes target prot opt in out source destination
26055 1221K LOG all -- any any anywhere anywhere limit: avg 3/min burst 10 LOG level warning prefix "[UFW BLOCK] "
Chain ufw-after-logging-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-after-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-forward (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED
0 0 ACCEPT icmp -- any any anywhere anywhere icmp destination-unreachable
0 0 ACCEPT icmp -- any any anywhere anywhere icmp source-quench
0 0 ACCEPT icmp -- any any anywhere anywhere icmp time-exceeded
0 0 ACCEPT icmp -- any any anywhere anywhere icmp parameter-problem
0 0 ACCEPT icmp -- any any anywhere anywhere icmp echo-request
0 0 ufw-user-forward all -- any any anywhere anywhere
Chain ufw-before-input (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- lo any anywhere anywhere
91131 11M ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED
259 12953 ufw-logging-deny all -- any any anywhere anywhere ctstate INVALID
259 12953 DROP all -- any any anywhere anywhere ctstate INVALID
0 0 ACCEPT icmp -- any any anywhere anywhere icmp destination-unreachable
0 0 ACCEPT icmp -- any any anywhere anywhere icmp source-quench
0 0 ACCEPT icmp -- any any anywhere anywhere icmp time-exceeded
0 0 ACCEPT icmp -- any any anywhere anywhere icmp parameter-problem
268 15308 ACCEPT icmp -- any any anywhere anywhere icmp echo-request
0 0 ACCEPT udp -- any any anywhere anywhere udp spt:bootps dpt:bootpc
45965 2305K ufw-not-local all -- any any anywhere anywhere
0 0 ACCEPT udp -- any any anywhere 224.0.0.251 udp dpt:mdns
0 0 ACCEPT udp -- any any anywhere 239.255.255.250 udp dpt:1900
45965 2305K ufw-user-input all -- any any anywhere anywhere
Chain ufw-before-logging-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-logging-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-before-output (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- any lo anywhere anywhere
189K 32M ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED
1359 123K ufw-user-output all -- any any anywhere anywhere
Chain ufw-logging-allow (0 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- any any anywhere anywhere limit: avg 3/min burst 10 LOG level warning prefix "[UFW ALLOW] "
Chain ufw-logging-deny (2 references)
pkts bytes target prot opt in out source destination
238 11693 RETURN all -- any any anywhere anywhere ctstate INVALID limit: avg 3/min burst 10
10 600 LOG all -- any any anywhere anywhere limit: avg 3/min burst 10 LOG level warning prefix "[UFW BLOCK] "
Chain ufw-not-local (1 references)
pkts bytes target prot opt in out source destination
45965 2305K RETURN all -- any any anywhere anywhere ADDRTYPE match dst-type LOCAL
0 0 RETURN all -- any any anywhere anywhere ADDRTYPE match dst-type MULTICAST
0 0 RETURN all -- any any anywhere anywhere ADDRTYPE match dst-type BROADCAST
0 0 ufw-logging-deny all -- any any anywhere anywhere limit: avg 3/min burst 10
0 0 DROP all -- any any anywhere anywhere
Chain ufw-reject-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-reject-output (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-skip-to-policy-forward (0 references)
pkts bytes target prot opt in out source destination
0 0 DROP all -- any any anywhere anywhere
Chain ufw-skip-to-policy-input (7 references)
pkts bytes target prot opt in out source destination
74 4530 DROP all -- any any anywhere anywhere
Chain ufw-skip-to-policy-output (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- any any anywhere anywhere
Chain ufw-track-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-input (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-track-output (1 references)
pkts bytes target prot opt in out source destination
659 76027 ACCEPT tcp -- any any anywhere anywhere ctstate NEW
26 1761 ACCEPT udp -- any any anywhere anywhere ctstate NEW
Chain ufw-user-forward (1 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-input (1 references)
pkts bytes target prot opt in out source destination
12922 761K ACCEPT tcp -- any any anywhere anywhere tcp dpt:ssh
1 57 ACCEPT udp -- any any anywhere anywhere udp dpt:ssh
Chain ufw-user-limit (0 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- any any anywhere anywhere limit: avg 3/min burst 5 LOG level warning prefix "[UFW LIMIT BLOCK] "
0 0 REJECT all -- any any anywhere anywhere reject-with icmp-port-unreachable
Chain ufw-user-limit-accept (0 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- any any anywhere anywhere
Chain ufw-user-logging-forward (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-input (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-logging-output (0 references)
pkts bytes target prot opt in out source destination
Chain ufw-user-output (1 references)
pkts bytes target prot opt in out source destination
答案1
肯定是防火墙问题。您的 ssh 服务器有响应，但我无法访问您的 TCP 端口 80。
更新 ：
TCP 端口 80 未打开。相关 Linode 文档对此提出了一些建议。
iptables -A INPUT -p tcp --dport 80 -m state --state NEW -j ACCEPT
或者正如@Ollie_W 指出的那样：
ufw allow 80/tcp