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View Full Version : [ubuntu] Newbie: Just installed Ubuntu 9.10, but port 80 blocked?



danandjan
April 13th, 2010, 02:20 AM
Hello, I am completely new to Linux. I installed Ubuntu 9.10 and tomcat 6 java servlet container. I am trying to run the tomcat server on port 80, so I edited tomcat's configuration file (server.xml) and changed the default port from "8080" to "80". I launched tomcat server, went to my browser and entered: "http:/myIP/mywebapp", but it says can not find server/location. Then I edit the server.xml and revert back to port "8080" and then enter: "http://myIP:8080/mywebapp" and everything works fine. So my guess is some other service is taking up port 80, but I would think not, since I just installed Ubuntu and made sure apache isn't installed or running.

So I went to "System" --> "Administration", then choose "Network Tools". I then executed Netstat and did not see anything taking up port 80, but I do see port 8080 taken (assuming it is the tomcat server). Then I also did a Port Scan and entered my IP number. Again, I don't see port 80 taken, but do see 8080 being used.

I had a winxp laptop computer behind home wireless and was running tomcat 6 server fine with it, but it over-heated and died recently. So I got a used laptop and just installed Ubuntu 9.10. I have not changed my wireless router settings. It is the same as before. So I have ruled out my home's hardware/network equipment.

So here now I sit, wondering what is up?? :-)

For security reasons, is port 80 initially blocked by Ubuntu for some reason? Is there something I have to do beforehand to free up port 80?
Thanks in advance for any help you can provide.

EDIT/UPDATE:
Errr! I found this forum post:
http://ubuntuforums.org/showthread.php?t=803801

According to one of the posters, he states the following:
"All ports below 1024 can only be opened by root. Apache, for example, uses some nice tricks to use port 80 and still be safe. I don't know about Tomcat (I always run it on 8080).

Allowing ports through a firewall (ufw seems to be a tool to control iptables) is something completely different."

Is this TRUE? That sucks...:-( Oh well, I guess people will have to type an extra 5 characters in the URL.

-Dan

Iowan
April 14th, 2010, 02:47 AM
I'm hoping your thread gets better support in the Server Platforms forum.
(A little "bump" might not hurt, either...)

danandjan
April 15th, 2010, 02:21 AM
Thanks. It turns out it was indeed related to Linux's privilege strictness. I ran sudo -s command to switch to root user then started the tomcat server. Now it lets me run port 80. I just wished there was some kind of error message or some other kind of indication. Oh well, not like Ubuntu comes with a manual. Thank goodness for Google although when I was taking CS classes, Google didn't exist back then. These young people sure got it easy. :-)