I can't connect to localhost from other computers

I can see the web pages I created in /var/www/html/ by typing localhost in URL bar.

A few months ago I could even access those pages by typing my ip address from other computers, but now I am getting server timed out when I type my ip address from my mobile phone; my friends are also not able to connect by typing my ip address.

Recently I installed webmin from a tutorial in unixmen, I thought maybe it changed read and execute permissions. so I executed the command chmod -R 775, but it didn't change anything (still not able to connect from other computers).

Everything is working fine from host computer.

The output of ifconfig is:

eth0      Link encap:Ethernet  HWaddr 08:9e:01:00:10:ad  
          inet addr:183.83.83.29  Bcast:183.83.127.255  Mask:255.255.192.0
          inet6 addr: fe80::a9e:1ff:fe00:10ad/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:443584 errors:0 dropped:0 overruns:0 frame:0
          TX packets:378897 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:470991396 (470.9 MB)  TX bytes:96527317 (96.5 MB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:154813 errors:0 dropped:0 overruns:0 frame:0
          TX packets:154813 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:20729684 (20.7 MB)  TX bytes:20729684 (20.7 MB)

pan1      Link encap:Ethernet  HWaddr 42:dd:4f:ed:a2:f2  
          inet addr:10.141.41.1  Bcast:10.141.41.255  Mask:255.255.255.0
          inet6 addr: fe80::40dd:4fff:feed:a2f2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:174 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:32909 (32.9 KB)

Solution 1:

Thank you everyone, I think it was the firewall, by disabling the firewall as given in the site https://help.ubuntu.com/12.04/serverguide/firewall.html with the command:

sudo ufw disable

I could open the index page from mobile.