First there was HTTP, then HTTP/2 and now HTTP/2 over the QUIC protocol. Lets have a look at the available HTTP Clients and Servers that support HTTP/2 and the experimental QUIC protocol. Introduction The Hypertext Transfer Protocol (HTTP) was invented in 1991. Up to 2015 then there was only little to no evolution. In 2015 the HTTP/2 protocol was defined as a standard. HTTP/2 is much more efficient that its ancestors. It features multiplexing, stream prioritization, binary transmission and much ….Read More
Tag: Fedora
Blueborne – How to disable Bluetooth in Fedora
Yesterday 2017-09-13 Redhat released infomation about the mitigation of the Blueborne vulnerability in RHEL: https://access.redhat.com/security/vulnerabilities/blueborne. For Fedora the new updates are probably still in the build queue and/or being QAed by the community. For a quick fix, you can disable Bluetooth similar than in RHEL: Stopping Bluetooth related service systemctl stop bluetooth.service systemctl disable bluetooth.service systemctl mask bluetooth.service Disable the Kernel modules echo “install bnep /bin/true” >> /etc/modprobe.d/disable-bluetooth.conf echo “install bluetooth /bin/true” >> /etc/modprobe.d/disable-bluetooth.conf echo “install btusb /bin/true” >> /etc/modprobe.d/disable-bluetooth.conf ….Read More
Configure SSSD to work on IPv6-only Hosts
SSSD is used for the client side of IPA and other centralized Identity Management Services. Unfortunately it does not behave as it should. The default is to look up first IPv4 addresses and if that fails IPv6 should be used. Well, if IPv4 fails, the whole request fails and you got weird error messages when joining an IPA domain. As the pool for IPv4 addresses is depleted, IPv6 is getting more and more important. Thus, IPv6-only hosts are on the ….Read More
Secure your system with SELinux
Introduction to SELinux SELinux is well known as the most sophisticated Linux Mandatory Access Control (MAC) System. If you install any Fedora or Redhat operating System it is enabled by default and running in enforcing mode. So far so good. Its available for many years and its not rocket science to use it. This article is supposed to give you some hints how to make your system even more secure and how to solve some troubles SELinux may have on your system. DAC ….Read More
Updating Fedora to version 23 – how to workaround some issues
After upgrading two machines from Fedora 22 to 23 I stumbled upon some severe issues. Most of them are easy to solve. This weekend I’ve found some time to upgrade my headless router and one of my workstations. Unfortunately is did not went that smooth like the past few upgrades. No initrd created and grub config lacks initrd reference This seems to be connected to the Plymouth issue as described here: Common F23 bugs. On my headless machine I only ….Read More
Using OTP Tokens and 2FA with FreeIPA 4.0
On 2014-07-08 FreeIPA 4.0 was released. One of the most interesting new features is the support of two factor authentication (2FA). I was curious about how to set it up and get it running. Unfortunately the documentation does not tell much about the OTP setup. What is OTP and 2FA? An overview OTP stands for One Time Password and 2FA for two factor authentication. OTP is available since long time, in the beginning usually as a list of passwords printed ….Read More
Kernel 3.5.3 partially broken for virtualization
Some time ago, Fedora 17 got a Kernel update to 3.5.3-1. Since then, PXE booting virtual machines does not work anymore. It seems that it has not been fixed in the upstream Kernel, but only the 3.5 series of Kernels is affected. A bug has been filed, but no fix is available. The only solution for now is to stick to Kernel 3.4.5-2. I’ve checked the Fedora annouce mailinglist, looks like there have been no grave bugfixes since then. The ….Read More
How to get a RTL2832U based DVB-T stick working on Fedora 17
This week I bought a no-name DVB-T stick with the risk to not getting it working with Linux. The device contains a RTL2832u chip which seems to be quite common according to this list. The price tag was just €14, so I was taking the risk. First experiments shown that there is no chance to get it running on Fedora 17. After digging deeper I figured out that someone wrote a driver and published it on github. Later on, I ….Read More