Save iptables on Shutdown and Restart, and Restore on Boot

Tuesday, October 6th, 2015

Save iptables Rules on Shutdown, Restore on Boot

When your server shutsdown (halts), reboots, or enters runlevel 1, your iptables configuration is automatically wiped and reset.  Packages such as iptables-persistent supposedly help with this problem, but unless you save your rules manually, the rules are never saved automatically when the system reboots. 

I've wanted to truly persist my iptables, so I decided to change their package to always save the iptables rules when the system reboots, halts, or enters runlevel 1 automatically.  The rules are then restored when the system boots to runlevels 2-5.  This means that your iptables configuration will persist forever.  This may not be desired, but if I ban an IP address permanently, I always want it to be banned.

If you'd like to use this modified version of iptables-persistent so that your rules are automatically saved on shutdown, you can install it by running the below commands:

sudo apt-get remove iptables-persistent
sudo dpkg -r iptables-persistent
wget http://dinofly.com/files/linux/iptables-persistent_0.5.8_all.deb
sudo dpkg --install iptables-persistent_0.5.8_all.deb

Use at your own risk.  If you do something stupid, it will persist until you can clear it!

The above package was tested in Ubuntu 12.04 x86, Ubuntu 12.04 x64, Ubuntu 14.04 x86, Ubuntu 14.04 x64, and Ubuntu 15.04 x64.  Should work on other debian operating systems as well.

Windows XP x86 and x64 .NET 4.0 Post Installation Slow Startup Network LAN Devices Fix

Thursday, March 29th, 2012

Windows XP .NET 4.0 Post Slow Startup Fix

I've been running my main machines on Windows XP x64 for several years, and I am a .NET developer.  There came a day when I needed .NET 4.0 for my development projects.  After installing .NET 4.0 in Windows XP x64 SP2, I noticed a slow bootup despite the fact that I have a solid state drive.  Windows would always boot up and freeze for about a minute before the network LAN and Wireless LAN computer icons appeared in the system tray.  At first, I never realized the problem was caused directly from the install of .NET 4.0.  For over a year I tried troubleshooting the problem.  I noticed that I had this problem on all of my XP machines after installing .NET 4.0.  I suspected video drivers, LAN drivers, wireless LAN drivers, and even my BIOS.  Nothing fixed this issue.  After further searching, I finally found a thread describing the same issues I was having.  Save yourself the read, and just run this batch file I wrote after installing .NET 4.0 on ANY Windows XP x64 or x86 machine:

set I=%windir%\
%I:~0,2%
cd %windir%\Microsoft.NET\Framework\v1.1.4322
ngen update
cd \
cd %windir%\Microsoft.NET\Framework\v2.0.50727
ngen update
cd \
cd %windir%\Microsoft.NET\Framework\v4.0.30319\
ngen update
sc stop "clr_optimization_v4.0.30319_32"
sc stop "clr_optimization_v4.0.30319_64"
sc config "clr_optimization_v4.0.30319_32" start= disabled
sc config "clr_optimization_v4.0.30319_64" start= disabled
@echo off
echo.
echo. All operations have been completed successfully.  The .net 4.0 framework services were disabled, as they are no longer needed.  This will not affect .net 4.0 applications, and your startup boot time should be back to instant!
pause

I have not experienced the slow boot issue on Windows Vista or Windows 7 after installing .NET 4.0.  Thus, please run this batch file on your XP machines after .NET 4.0.  If you don't, I hope you enjoy headaches.

Keep Num Lock On at Startup on Windows Computers

Thursday, March 29th, 2012

Windows XP, Vista, and Windows 7 :: Keep Num Lock On at Startup

Despite what Microsoft claims, I've seen some computers not revert back to their last set num lock setting when Windows was last shut down.  Granted, this could be caused by Enterprise configurations.Here's a simple batch file that should keep Num Lock always ON when a user logs in.  It may or may not need to be run with administrator privileges based on your enterprise configuration.  I've had several users complain about the fact that Num Lock is turned off when they turn on their computers in the morning.  As a result, this batch file allows you to enable the setting that keeps num lock enabled after a user logs in with minimal effort.  I'm still under the impression that this is more work than the user simply pressing the num lock key to turn it back on.

REGEDIT4
@ECHO OFF
CLS
REGEDIT.EXE /S "%~f0"
EXIT

[HKEY_CURRENT_USER\Control Panel\Keyboard\]
"InitialKeyboardIndicators"="2"