Kategori: Data, IT og Internett

I use PowerTOP to get the most out of my battery on my laptop. Since PowerTOP doesn’t remember the settings from the previous bootup, I’ve made this quick and dirty SystemD unit file to fix my powertop settings on each boot:

[Unit]
Description=PowerTOP tunings

[Service]
Type=oneshot
ExecStart=/usr/sbin/powertop --auto-tune

[Install]
WantedBy=multi-user.target

Save it in /etc/systemd/system/powertop.service, run systemctl daemon-reload; systemctl enable powertop.service, and Bob’s your uncle.

Most, if not all, day to day management tasks for Microsoft Exchange Server 2013 can be achieved via your web browser by accessing the so called «Exchange Administration Center» with your browser. This is very nice for those of us who don’t run Windows on their desktop, and should allow for a little less RDP in our lives. However, some of the modal dialogues (as in «Edit» or «New» dialogues for e-mail addresses, certificates, server aliases etc.) refuse to pop up in Google Chrome (as of Chrome 37).

I could of course have started to use Firefox to manage Exchange, but that would only be a small step away from running RDP anyway, so here’s how you can (TEMPORARILY) re-enable the showModalDialog API in Google Chrome under Linux:

If you’re reading this after May 1st 2015, then I’m sorry, you’ll have to use something else to manage Exchange.

First, create the directories needed to hold Chrome Policies:

sudo mkdir -p /etc/opt/chrome/policies/managed

Next, create a policy file to hold our new policy setting:

sudo nano /etc/opt/chrome/policies/managed/showmodal.json

And add this as its content:

{
 "EnableDeprecatedWebPlatformFeatures": ["ShowModalDialog_EffectiveUntil20150430"]
}

Then completely restart Chrome (confirm that no chrome process is running before starting it again, Chrome likes to leave a systray running etc.).

Once Chrome has been restarted, you can check if your new policy has been picked up by checking chrome://policy, something like this should be showing up:

If you have access to multicast television in your network (such as UNINETT’s IPTV offer), and you’re running Ubuntu’s «Uncomplicated Firewall» aka. ufw, you’ll find that you’re unable to actually watch any of the channels. Here’s how you can adjust your firewall to receive the UDP multicast traffic:

sudo ufw allow in proto udp to 224.0.0.0/4
sudo ufw allow in proto udp from 224.0.0.0/4

This will take care of the coming and going UDP packets, but you also need to allow IGMP packets through. I haven’t found any command to make this change, so instead, you need to open up the file
/etc/ufw/before.rules
and add the following lines somewhere before the COMMIT line:

# allow IGMP
-A ufw-before-input -p igmp -d 224.0.0.0/4 -j ACCEPT
-A ufw-before-output -p igmp -d 224.0.0.0/4 -j ACCEPT

Now you can reload the firewall and you should be able to watch that glorious multicast IPTV.