Question posted in 
Environment:debian9 + apache2.
ifconfig
enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.31.52 netmask 255.255.255.0 broadcast 192.168.31.255
The setting for apache2.
sudo cat /etc/apache2/sites-enabled/000-default.con
<VirtualHost 192.168.31.52:80>
DocumentRoot /home/content/mydoc
</VirtualHost>
<VirtualHost *:80>
ServerName localhost
DocumentRoot /home/content/mydoc
<FilesMatch ".(html|htm|js|css|json)$">
FileETag None
<IfModule mod_headers.c>
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Note "CACHING IS DISABLED ON LOCALHOST"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</IfModule>
</FilesMatch>
Alias /wp "/var/www/html/wp"
<Directory /var/www/html>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>
</VirtualHost>
When to input 127.0.0.1 in my local pc’s firefox ,all webpage in /home/content/mydoc displayed.
When to input 127.0.0.1/wp in my local pc’s firefox ,all webpage in /var/www/html/wp displayed.
When to input 192.168.31.52 in my local pc’s firefox ,all webpage in /home/content/mydoc displayed.
When to input 192.168.31.52/wp in my local pc’s firefox ,all webpage in /var/www/html/wp displayed.
Now i want to open webpage page in /home/content/mydoc with my android phone,input http://192.168.31.52 ,why can’t connect to the apache2 server in pc via my android phone’s firefox?
sudo iptables -L -v
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
7204 7355K ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED
44 2578 ACCEPT all -- lo any anywhere anywhere
16 1638 INPUT_direct all -- any any anywhere anywhere
16 1638 INPUT_ZONES_SOURCE all -- any any anywhere anywhere
16 1638 INPUT_ZONES all -- any any anywhere anywhere
0 0 DROP all -- any any anywhere anywhere ctstate INVALID
16 1638 REJECT all -- any any anywhere anywhere reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- any any anywhere anywhere ctstate RELATED,ESTABLISHED
0 0 ACCEPT all -- lo any anywhere anywhere
0 0 FORWARD_direct all -- any any anywhere anywhere
0 0 FORWARD_IN_ZONES_SOURCE all -- any any anywhere anywhere
0 0 FORWARD_IN_ZONES all -- any any anywhere anywhere
0 0 FORWARD_OUT_ZONES_SOURCE all -- any any anywhere anywhere
0 0 FORWARD_OUT_ZONES all -- any any anywhere anywhere
0 0 DROP all -- any any anywhere anywhere ctstate INVALID
0 0 REJECT all -- any any anywhere anywhere reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT 6411 packets, 1521K bytes)
pkts bytes target prot opt in out source destination
6419 1521K OUTPUT_direct all -- any any anywhere anywhere
Chain FORWARD_IN_ZONES (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDI_public all -- + any anywhere anywhere [goto]
Chain FORWARD_IN_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain FORWARD_OUT_ZONES (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDO_public all -- any + anywhere anywhere [goto]
Chain FORWARD_OUT_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain FORWARD_direct (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDI_public_log all -- any any anywhere anywhere
0 0 FWDI_public_deny all -- any any anywhere anywhere
0 0 FWDI_public_allow all -- any any anywhere anywhere
0 0 ACCEPT icmp -- any any anywhere anywhere
Chain FWDI_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain FWDI_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public (1 references)
pkts bytes target prot opt in out source destination
0 0 FWDO_public_log all -- any any anywhere anywhere
0 0 FWDO_public_deny all -- any any anywhere anywhere
0 0 FWDO_public_allow all -- any any anywhere anywhere
Chain FWDO_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain FWDO_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain INPUT_ZONES (1 references)
pkts bytes target prot opt in out source destination
16 1638 IN_public all -- + any anywhere anywhere [goto]
Chain INPUT_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain INPUT_direct (1 references)
pkts bytes target prot opt in out source destination
Chain IN_public (1 references)
pkts bytes target prot opt in out source destination
16 1638 IN_public_log all -- any any anywhere anywhere
16 1638 IN_public_deny all -- any any anywhere anywhere
16 1638 IN_public_allow all -- any any anywhere anywhere
0 0 ACCEPT icmp -- any any anywhere anywhere
Chain IN_public_allow (1 references)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpt:ssh ctstate NEW
Chain IN_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain IN_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain OUTPUT_direct (1 references)
pkts bytes target prot opt in out source destination
2
Answers
Assuming httpd is started and listening on every interfaces, and that the Android device is on the same network, a possible cause is the firewall blocking the connection, use :
to list the filter rules.
You can (temporarily) add a rule to allow connection to the http port :
If it does solve the problem, you will have to find how your firewall is configured to make the change more permanent.