how to get around isp blocking port 80 or 25

ISP generally blocks ports to "protect" their customers from viruses and spam. We have already discussed in previous post as how to detect whether your ISP is blocking
port or not.The most commonly blocked ports are port 80 and port 25.

Here is a tutorial that will help you to override this problem.

In this tutorial paris (blogger name) discusses that how can we configure Apache server to operate

 

Change configuration in ports.conf file:

View Raw Code?
su
nano /etc/apache2/ports.conf

(don't close this terminal since all the following commands require root privileges)

Change lines 8, 9 to:

View Raw Code?
NameVirtualHost *:8080
Listen 8080

save and close nano.
Change configuration in default file:

View Raw Code?
nano /etc/apache2/sites-available/default

Change the first line to:
View Raw Code?
<VirtualHost *:8080>

save and close nano.
Restart apache!:

View Raw Code?
/etc/init.d/apache2 restart
 

Now lets visit canyouseeme.org and see if it worked.

Type in the box under your ip 8080 and then check.If it worked you should get the message:

Success: I can see your service on xxx.xxx.xxx.xxx on port (8080) Your ISP is not blocking port 8080

(Where xxx.xxx.xxx.xxx your IP)

Now everyone can visit your /var/www folder just by typing your ip and port you used, like that: xxx.xxx.xxx.xxx:8080

UPDATE : You might need to set your pc to be DMZ on your router settings: By visiting http://192.168.1.1/ you have access to your router. (applies on most routers)

 

Here is another tutorial that might help you to do the same but in different way (using microsoft IIS)

http://www.no-ip.com/support/guides/web_servers/isp_block_port_80.html