Source IP Address Based on User

If you want to use different source IP addresses based on the logged in user or running service on a Linux computer you can use these simple commands: /sbin/ifconfig eth0:1 NEW-IP-ADDRESS netmask YOUR-NORMAL-NETMASK /sbin/iptables -t nat -A POSTROUTING -m owner –uid-owner USERNAME -j SNAT –to-source NEW-IP-ADDRESS You can use this if the source IP is …

Continue reading ‘Source IP Address Based on User’ »

Android Battery Drain Riddle!

Problem: an android phone is loosing battery very quickly. The battery settings don’t show any app, the display or other reasons for the battery drain. Discussion: I found out that the battery drain is only when connected to WLAN. Then I recognized that it only happens when connected to my WLAN. The mobile phone never sleeps when …

Continue reading ‘Android Battery Drain Riddle!’ »

FlexFabric 5700 Backup Config to TFTP in MGMT VPN-Instance

Problem: if you separate the management from the normal traffic on a switch you will usually configure the swtich via this mgmt vpn-instance and also backup and restore config files via this mgmt vpn-instance. But if you use the “backup startup-configuration to ..” it always tries to find the tftp server on the normal network Even after changing …

Continue reading ‘FlexFabric 5700 Backup Config to TFTP in MGMT VPN-Instance’ »

NVidia Driver on Linux-4.11.1

Problem: after installing linux kernel 4.11.1, the dkms package of the nvidia driver does not compile. You find some cryptic error message about ./Kbuild in  /var/lib/dkms/nvidia-current/375.39/build/make.log Solution: I uninstalled the debian nvidia package and installed the newer driver from the NVidia homepage: aptitude remove nvidia-installer-cleanup ./NVIDIA-Linux-x86_64-375.66.run After this upgrade nvidia and linux 4.11.1 works again Versions: before upgrade jessie …

Continue reading ‘NVidia Driver on Linux-4.11.1’ »

Ubiquiti UniFi the Next Botnet ?

I tested a Ubiquiti access point today. UAP-AC-Lite seems to be a very good and cheap access-point. When you take it out of the box and connect it to the network it gets an IP address using DHCP and waits for a configuration. In this mode it sends broadcasts to find a controller and listens on port …

Continue reading ‘Ubiquiti UniFi the Next Botnet ?’ »

Firefox Audio is Broken due to PulseAudio Dependency

Problem: Firefox 52 audio does not work without pulseaudio. Discussion: pulseaudio is a bloated audio daemon that often fails. In the last years, when ever audio failed on linux, the quickest solution was to uninstall pulseaudio. But the Firefox developers made the mistake to remove support for the underlying audio driver alsa, and insist on the middle …

Continue reading ‘Firefox Audio is Broken due to PulseAudio Dependency’ »

Sophos UTM BGP Announces 0 Prefixes

Problem: A simple bgp upstream configuration. A small AS with one IP prefix wants to connect to its upstream using BGP. The BGP peerings are up. Sophos receives the expected routes from its upstream, but the upstream router does not receive the expected single prefix. Discussion: an outbound filter list is set to prevent sending other than the …

Continue reading ‘Sophos UTM BGP Announces 0 Prefixes’ »