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Full Discussion: Question about blocking incomming traffic
Special Forums IP Networking Question about blocking incomming traffic Post 302865735 by bakunin on Saturday 19th of October 2013 02:00:34 PM
Old 10-19-2013
Quote:
Originally Posted by LMHmedchem
Thank you for this very informative post. This is what I was looking for. If I read this right, my router will automatically block incoming connections unless I have set up port forwarding to allow it. Further, unless I am running the service that the connection is looking for, the connection would be refused anyway.
Exactly.

Quote:
Is there any way for there to be intrusion on port 80, since that will be used for normal internet traffic?
I am not sure if i understand the question correctly. Port 80 is for hypertext transport protocol (http). It is the default port a web server (=httpd, http-daemon) uses. Suppose you use http to surf to some web site:

You send a request to some site, using http and contacting port 80 at, say, remote.site.com.

The httpd (read: apache, tomcat, IIS, ...) sits there at the server and listens at port 80 when your request comes in.

It picks it up, creates an answer (=web page) and sends it to you, using some unspecified free port on its own system and port 80 at yours.

Your http-client (read: web browser) takes this message apart, creates an answer (for instance, by you clicking on a link, etc.) an sends it back, etc..

A "message" in http is similar to an MIME e-mail in format. It can consist of several parts (pictures, scripts, ...) and of course one (or even several) of these parts can contain malicious code. If you download such code and you run a widespread graphical interrupt handler instead of an OS, your system could become infected with some malware, adware, virus, worm, ...

You would have gotten this malicious code through your port 80, like all the other http messages you get. Closing it would simply forbid any http traffic and effectively prohibit http-connections of any sort. You can either use some scanner inspecting what comes through port 80 (this is how virus scanners work - they pose as daemons listening at port 80 and only pass to the originally intended client after having inspected what comes through) or use a system which cannot be affected by malicious code. Code, malicious or not, will not carry out its purpose until being run and it runs with the privileges of the user running it. This is why it is a very bad idea to surf the web as "root" in Unix. Alas, some OSes are only usable as "Administrator" and so the problem starts.

I am not sure if i have addressed your concern. In case i haven't: please ask clearly, what you want to know.

I hope this helps.

bakunin
 

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LEARN ABOUT XFREE86

git-instaweb

GIT-INSTAWEB(1) 						    Git Manual							   GIT-INSTAWEB(1)

NAME

       git-instaweb - Instantly browse your working repository in gitweb

SYNOPSIS

       git instaweb [--local] [--httpd=<httpd>] [--port=<port>]
		      [--browser=<browser>]
       git instaweb [--start] [--stop] [--restart]

DESCRIPTION

       A simple script to set up gitweb and a web server for browsing the local repository.

OPTIONS

       -l, --local
	   Only bind the web server to the local IP (127.0.0.1).

       -d, --httpd
	   The HTTP daemon command-line that will be executed. Command-line options may be specified here, and the configuration file will be
	   added at the end of the command-line. Currently apache2, lighttpd, mongoose, plackup and webrick are supported. (Default: lighttpd)

       -m, --module-path
	   The module path (only needed if httpd is Apache). (Default: /usr/lib/apache2/modules)

       -p, --port
	   The port number to bind the httpd to. (Default: 1234)

       -b, --browser
	   The web browser that should be used to view the gitweb page. This will be passed to the git web--browse helper script along with the
	   URL of the gitweb instance. See git-web--browse(1) for more information about this. If the script fails, the URL will be printed to
	   stdout.

       start, --start
	   Start the httpd instance and exit. Regenerate configuration files as necessary for spawning a new instance.

       stop, --stop
	   Stop the httpd instance and exit. This does not generate any of the configuration files for spawning a new instance, nor does it close
	   the browser.

       restart, --restart
	   Restart the httpd instance and exit. Regenerate configuration files as necessary for spawning a new instance.

CONFIGURATION

       You may specify configuration in your .git/config

	   [instaweb]
		   local = true
		   httpd = apache2 -f
		   port = 4321
		   browser = konqueror
		   modulePath = /usr/lib/apache2/modules

       If the configuration variable instaweb.browser is not set, web.browser will be used instead if it is defined. See git-web--browse(1) for
       more information about this.

SEE ALSO

       gitweb(1)

GIT

       Part of the git(1) suite

Git 2.17.1							    10/05/2018							   GIT-INSTAWEB(1)
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