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Firewall is not configered is linux centos

How to configer squid and iptables in linux centos pls, give me a help for
step by step configer on linux

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Re: firewall is not configered is linux centos

Try and go for it..all d best...

Use yum command as follows:
# yum install squid
Loading "installonlyn" plugin Setting up Install Process Setting up repositories Reading repository metadata in from local files Parsing package install arguments Resolving Dependencies --> Populating transaction set with selected packages. Please wait. ---> Package squid.i386 7:2.6.STABLE6-4.el5 set to be updated --> Running transaction check Dependencies Resolved ============================================================================= Package Arch Version Repository Size ============================================================================= Installing: squid i386 7:2.6.STABLE6-4.el5 updates 1.2 M Transaction Summary ============================================================================= Install 1 Package(s) Update 0 Package(s) Remove 0 Package(s) Total download size: 1.2 M Is this ok [y/N]: y Downloading Packages: Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing: squid ######################### [1/1] Installed: squid.i386 7:2.6.STABLE6-4.el5 Complete! Squid Basic Configuration Squid configuration file located at /etc/squid/squid.conf. Open file using a text editor:
# vi /etc/squid/squid.conf
At least you need to define ACL (access control list) to work with squid. The defaults port is TCP 3128. Following example ACL allowing access from your local networks and Make sure you adapt to list your internal IP networks from where browsing should be allowed:
acl our_networks src
http_access allow our_networks
Save and close the file. Start squid proxy server:
# chkconfig squid on
# /etc/init.d/squid start
init_cache_dir /var/spool/squid... Starting squid: . [ OK ] Verify port 3128 is open:
# netstat -tulpn | grep 3128
tcp 0 0* LISTEN 20653/(squid) Open TCP port 3128 Finally make sure iptables is allowing to access squid proxy server. Just open /etc/sysconfig/iptables file:
# vi /etc/sysconfig/iptables
Append configuration:
-A RH-Firewall-1-INPUT -m state --state NEW,ESTABLISHED,RELATED -m tcp -p tcp --dport 3128 -j ACCEPT
Restart iptables based firewall:
# /etc/init.d/iptables restart
Flushing firewall rules: [ OK ] Setting chains to policy ACCEPT: filter [ OK ] Unloading iptables modules: [ OK ] Applying iptables firewall rules: [ OK ] Loading additional iptables modules: ip_conntrack_netbios_n[ OK ] Client configuration Open a webbrowser > Tools > Internet option > Network settings > and setup Squid server IP address and port # 3128.
See also You may find our previous squid tips useful:

Posted on Jun 22, 2009

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I cant set up my linksys wireless-G ADSL, my laptop recognizes linksys but i still cant connect to the internet, when i clicked on troubleshoot to correct the problem, it says DNS isnt recognized

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Resolution Suggestion One:

# Test your Internet connection to Windows Update.

A simple solution but one that works in many circumstances!

Test to determine if your Internet connection is preventing you from reaching the Windows Update Web site. To do this, visit the following Microsoft Windows Update Web site to determine if you can download the file:

If a file download dialog box appears, the problem is not with your Internet connection. Click Cancel. If you cannot connect to this link, and you receive a "Page Cannot Be Displayed" error message, your Internet connection is preventing you from reaching the Windows Update site.



Resolution Suggestion Two:

# Reconfigure or update your firewall program.

Reconfigure or update your firewall program so that Windows Update is not blocked, and then try to update your computer again by using Windows Update. For information about how to reconfigure or update your firewall program, see the documentation that was included with the program, view the Help files for your program, or contact the manufacturer's technical support department.

e.g It my mean Opening TCP/IP 443 in both directions for this process: %windir%\system32\svchost.exe


Resolution Suggestion Three:

# Remove Windows Update entries from the HOSTS file.

To remove Windows Update entries from the HOSTS file, follow these steps:

-Click Start, point to All Programs, point to Accessories, and then click Notepad
-On the File menu, click Open.
-In the Files of type box, click All Files.
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-Double-click to open the hosts file.
-Remove any lines that contain entries for Windows Update (
-On the File menu, click Save.
-Close Notepad.

I have seen the 0x80072EFD error resolved by this tip many times...



Resolution Suggestion Four:

# Run the IPCONFIG /FLUSHDNS command.

To run the ipconfig /flushdns command, follow these steps:

-Click Start, and then click Run.
-In the Open box, type cmd, and the click OK.
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ipconfig /flushdns

Close the command window.


Resolution Suggestion Five:

# Add Windows Update addresses to the trusted sites list.

To add Windows Update addresses to the trusted sites list, follow these steps:

-Open Microsoft Internet Explorer.
-Click Tools, and then click Internet Options.
-Click the Security tab, and then click Trusted Sites.
-Click Sites, and then click to clear the Require server verification (httpssmile.gif for all sites in this zone check box.
-In the Add this Web site to the zone box, type each of the following addresses, and click Add after each address:

-Click OK to close all Internet Options windows.


Resolution Suggestion Six:

# Add Windows Update addresses to the proxy settings exceptions list.

If your Internet connection uses a proxy server, add the Windows Update sites to the proxy settings exceptions in Internet Settings. To do this, follow these steps:

-Open Internet Explorer.
-Click Tools, and then click Internet Options.
-Click the Connections tab, and then click LAN Settings.
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Note If you are running third-party proxy or firewall software, see your product documentation for information about how to add these sites to the exception list for those applications.

Click OK to close all Internet Options windows.


Resolution Suggestion Seven:

# Change the MTU setting on your router.

Yours ISP's MTU for their connection may not be correctly setup on your Broadband router and/or your computer.

Please contact your ISP's support for more assistance on this. However the following articles may be of help:


Resolution Suggestion Eight:

# Configure Norton Internet Security 2003.

Norton Internet Security 2003 may be blocking Windows Update. try this:

-Open the Norton Internet Security 2003 Application
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