All posts by badbod

Centos 6 / 7 Openvpn forwarding not working

Seems Centos (thus RH) have changed the way things work slightly. Especially if you have multiple interfaces (NIC’s).

If your having problems with VPN not forwarding correctly, or your openVPN stopped working since updating from Centos 5, then this will most likely be what your looking for.

nano /etc/sysctl.conf


net.ipv4.conf.default.rp_filter = 1


net.ipv4.conf.default.rp_filter = 2

now reboot and enjoy.


Install Bitdefender Anti-Virus on Windows 10 technical preview.

If your having poroblems installing Bitdefender Anti Virus on Windows 10 technical preview, try this (works for me).

Download the Bitdefender installer from Bitdefender website. If you bought it online then use the link in your purchase email.

Place the file somewhere easy to get to, like c:\temp.

Now use the compression program of your choice to unpack the contents of the file. I use 7-zip, so right click the downloaded file and select ‘7-zip’ -> ‘Extract to’.

now open a command prompt as administrator and navigate to c:\temp

cd c:\temp
setupdownloader.exe /silent

The install is silent, there will be no on-screen progress or results. Just wait a minute or two (depending on your internet speed) while the program downloads and installs. Eventually you will see the Bitdefender program appear in the system tray.


Ubuntu 14.04 (Linux 64 bit) – No network, no USB 3 / USB 2

This mainly applies to 970 chipset mainboards, so your mileage may vary.

Symptom, no USB 3 , or Network, or USB 2 using Ubutnu 14.04 (actually from 12.04 up) 64 bit editions. As this is a kernel problem this should affect most 64 bit linux distros, not just Ubuntu.

There seems to be a problem with all recent 64 bit linux distros and 970 chipset mainboards.

There are 3 options.

1) Use a 32 bit distro.

2) In your BIOS enable IOMMU. This will fix your network and USB 2. You probably wont have USB 3 though ūüôĀ

3) Enable IOMMU in BIOS and add iommu=soft to your grub config. This gets rid of the stream of warnings you get at boot with IOMMU enabled in BIOS. USBB 3 should work too.

sudo nano /etc/default/grub

Change the line



GRUB_CMDLINE_LINUX_DEFAULT="quiet splash iommu=soft"

Then do

sudo update-grub

and reboot.

This should make the USB 2 and 3 work as well as networking.

Let me know what chipsets/mainboards this helped you with.

Changed option 3 as noted by Anthony Barnett. Many hanks for the feedback Anthony.


Asus DSL-N12U wireless.

Been playing with this wireless modem for a couple weeks now, and it is looking good.

As you would expect, it does the AP/Extender/router etc as needed. The real nice bit is the network map. From here I can see all clients and assign priority in a simple click interface. I am used to doing this in iptables, so very nice to point and click direct on the modem instead of having to have a gateway server; or far more expensive device.

Very impressive for a consumer device, though I am concerned about how ‘warm’ it is.

I had to tweak the SNR for good stability ( Stability Adjustment -3dB ) or I was getting DSL disconnect every ~8-~19 hours.

I am not used to having such options in consumer devices anyway. Very nice. My ISP supports modem down-rating for SNR so your mileage might vary.

One¬†down, I guess, is that it had to be tweaked. Looks to be aimed at the ‘enthusiast’ or ‘IT guy at home’ market. You have to understand the logs and adjust according to your connection. Somewhat above the average home user ability?

My main concern is how hot it is. Not uncommon with this type of device, sadly.

It is very stable and has much more control than I am used to for  a consumer priced device.

Very nice bit of kit. Same price as numb nuts devices but with ‘nerd’ perks. For the geeks amongst us I recommend this one.

Reliability setting at default 

SNR down 30.4 : SNR up 27.8 , DSL down every ~15 hours.

Reliability Setting at -3dB

SNR down 26.2 : SNR up 27.8 and has been up for over a week.

Given that SNR is acceptable at 6, then I can still play with it a lot more if it does decide to be unreliable.

Obviously I am looking for a reliable device. I go away for weeks at a time and need the device to continue working reliably. Once adjusted, the Asus appears to be doing exactly that.

For the non geeks, then I suggest you buy the most reasonably priced thing for your needs and put up with rebooting it now and then when it stops doing it’s job.

The Asus DSL-N12U wireless costs about the same as other home user wireless modems. It is not for the average home user though.