Remotely manage a Sonicwall firewall over a VPN tunnel

Earlier I was looking to remotely manage a Sonicwall firewall via HTTPS over a VPN tunnel that I had established to the device. In order to do this firstly select ‘VPN’ in the Sonicwall’s menu, the ‘Settings’ section should then be highlighted. Click the ‘configure’ button for the VPN tunnel that you want to manage the device over, which will open the settings screen for that VPN Policy. Next click the ‘Advanced’ tab, and look for the section labelled ‘Management via this SA’.  Check the boxes for protocols that you wish to manage the device over, and click OK, as shown below.

Allow remote management via HTTPS and SSH over a VPN tunnel on a Sonicwall Firewall

Allow remote management via HTTPS and SSH over a VPN tunnel on a Sonicwall Firewall

Empty a log file in Linux

I needed to empty a log file on one of my Linux boxes today as it had grown to 7.5 GB in size. This was achieved by simply running the following command in the directory where the problem file exists, and LOG_FILE was the name of the file to be emptied:

cat /dev/null > LOG_FILE

Citrix – The following requested video mode was not available

Recently we received the following error message when accessing Citrix Presentation Server on a few client machines which had had large wide screen monitor upgrades. The application that had been started would also not enter full screen mode.

The following requested video mode was not available: 1920 x 1080 x 24 BPP

The video mode has been set to the following mode: 1847 x 1038 x 24 BPP

Video mode restricted by administrator.

Citrix Error: The following requested video mode was not available

This was due to the fact that not enough memory had been allocated to the graphics for individual client sessions to support the resolution on larger monitors. This can be resolved by modifying the Farm ICA Display settings in the Citrix Access Management Console. Right click on the Farm object in the Citrix Access Management Console and choose ‘Properties’. Then under ‘Server Default’, ICA, click on ‘Display’. Change ‘Maximum memory to use for each sessions’s graphics’ from the default (in my case 5625) to 8192 as shown below:

Changing the 'Maximum memory to use for each session's graphics' setting under Server Default, ICA, Display

After increasing the memory available for each sessions graphics, you should find that Citrix is able to support the higher resolutions OK.