Software

This section looks at what is new in the world of software (Operating Systems included) and how to take best advantage of what is out there.

Having recently changed from using PowerShell ISE to VS Code I’m still discovering all the super awesome new features of it (be sure to get a copy of the Keyboard shortcuts from this page – https://code.visualstudio.com/docs/getstarted/keybindings). To get started I’ve changed the default new file language to PowerShell (not that you can’t change it to anything else though!).

To do this follow the short guide in the screenshots adding in the line shown in the gist below.

In putting together a small RDS (Session Based) environment on Server 2016 today today I kept running across the error message below during the installation.

Failed: Unable to install the role services.

After much back and forth between forums and event viewer it turns out our default policy to disable TLS 1.0 on servers was the issue. Enabling TLS 1.0 (through the registry or with the fantastic IIS Crypto – https://www.nartac.com/Products/IISCrypto) ended up sorting the issue for us.

Thanks to the organising committee of the (Oxford and Cambridge) College IT Conference 2018 held at the RAF Museum (Hendon) for the invite to talk about PowerShell and Server Core! As promised the video from the presentation is now up on YouTube; in addition the slides as PowerPoint and PDF can be seen below.

  Presentation (PowerPoint) (28.5 MiB, 50 hits)

  Presentation (PDF) (4.9 MiB, 42 hits)

30/03/2018 Update

Microsoft have published this blog post – https://cloudblogs.microsoft.com/windowsserver/2018/03/29/windows-server-semi-annual-channel-update which clarifies the difference between the Long-Term Servicing Channel (Server 2016/2019/so on) against the Semi-Annual Channel. Do have a read!

With thanks to the 50 staff from across the University for attending please see below the links to the videos and PowerPoints of the day!

Direct link to Playlist – https://www.youtube.com/watch?list=PLRxbdlgJzwyjAf820T0u4GpP0E01a9LEX&v=u-GVJ_0VuRM

Slides as PowerPoint

  1 Intro (4.3 MiB, 173 hits)

  2 MDT (85.2 MiB, 184 hits)

  3 PowerShell (27.5 MiB, 142 hits)

  4 PRTG Network Monitor (47.5 MiB, 172 hits)

  5 OpenVAS (32.9 MiB, 145 hits)

  6 WSUS and Chocolatey (60.3 MiB, 150 hits)

  7 NPS and VLANs (10.7 MiB, 181 hits)

Slides as PDF

  1 Intro (2.0 MiB, 165 hits)

  2 MDT (2.2 MiB, 191 hits)

  3 PowerShell (1.8 MiB, 173 hits)

  4 PRTG Network Monitor (3.2 MiB, 190 hits)

  5 OpenVAS (2.3 MiB, 195 hits)

  6 WSUS and Chocolatey (2.9 MiB, 210 hits)

  7 NPS and VLANs (1.4 MiB, 182 hits)

Stay tuned over the coming days for the scripts that are mentioned through the video which will be linked to from this post.

One of the often forgotten about features of gpresult is that it can output reports as HTML format (in a similar format to Group Policy Modelling) as well as to the command line – simply use the /h switch followed by a path. This includes much more useful data including how long it took to apply various aspects of the policy.

In the example below we can see that Group Policy Infrastructure took much longer to apply than expected (normally only a second or two), you can then dig into the cause by clicking the View Log link to the right which pops out even more detail to dig through. In this case the cause of the slow policy application appeared to be old ADM files (Windows XP era) being included with the policy; deleting the files resolved the issue.

This entry is part 4 of 4 in the series A Windows SysAdmin installs and uses OpenVAS

In my environment all of our network connected devices are configured to respond to PINGs; this mainly comes about from using PRTG Network Monitor to confirm that devices and services are up even in the most simple of fashions. The same also applies to client PCs which through Group Policy are configured to reply to PING. Thus to save OpenVAS some work while doing it’s scans I’ve got a custom scan configured (which will be used in later blog posts) that will only scan hosts which reply to PING.

Have a look at the screenshot sequence below to see how to configure such a scan.

A little bit of fun today with Milestone XProtect (in our case the express version) today; with the goal of improving our documentation I wanted to somehow obtain a list of all of the hardware devices (and to some degree the cameras) including there names, MAC addresses and IP addresses from our XProtect server.

Lone behold the configuration.xml file typically stored at “C:\ProgramData\Milestone\Milestone Surveillance\configuration.xml” held just the information I wanted; a little bit of PowerShell later and I had CSVs with the information in a human readable form.

To do the same on your server follow the guide using the Export-MilestoneConfig.ps1 script show below.

Download Export-MilestoneConfig.ps1 (download from GitHub)

If you are running an HPE Aruba (formally ProCurve) switch you may come across cases where your switch (in the example above a 5400R zl2) has multiple IP Addresses/VLANs and you need it to talk to another service (in my case syslog and sFlow receivers) on a set interface.

When this occurs you can use the ip source-interface command (make sure you are in config mode first) to define the IP Address or VLAN that you want the switch to talk out on. In my case VLAN2 which is used as the management network for the network switches (VLAN1 being the default network that switches use if multiple addresses are configured).

Not the first time I’ve run into this issue and probably won’t be the last! While building a new Windows Server 2016 (Full) Microsoft Deployment Toolkit server when attempting to run the ‘Update Deployment Share’ wizard I was getting the following error message.

Unable to mount the WIM, so the update process cannot continue.

The solution is simple; if you are running this machine on Hyper-V (presumably other Hypervisors as well) you will need to shutdown the VM, disable Secure Boot (on the VM only) and then power it back on. The next time you run the wizard it will complete as normal.

The error message in full context for reference.

=== Making sure the deployment share has the latest x86 tools ===
=== Making sure the deployment share has the latest x64 tools ===

=== Processing LiteTouchPE (x64) boot image ===

Building requested boot image profile.
Determining if any changes have been made in the boot image configuration.
No existing boot image profile found for platform x64 so a new image will be created.
Calculating hashes for requested content.
Changes have been made, boot image will be updated.
Windows PE WIM C:\Program Files (x86)\Windows Kits\10\Assessment and Deployment Kit\Windows Preinstallation Environment\amd64\en-us\winpe.wim will be used.
Unable to mount the WIM, so the update process cannot continue.

=== Completed processing platform x64 ===

 

=== Processing complete ===

This entry is part 3 of 4 in the series A Windows SysAdmin installs and uses OpenVAS

Following on from more work with OpenVAS and after resolving issues around PHP/MySQL the next largest priority was flagged as issues with the Remote Desktop Server (this applies if the server is being used as a Session Host or is just running Windows Server/Client). Here are two pointers in the right direction to get these port 3389 issues resolved!

SSL/TLS: Report Weak Cipher Suites and SSL/TLS: Diffie-Hellman Key Exchange Insufficient DH Group Strength Vulnerability

To resolve this issue I would suggest you look at the free IISCrypto tool (https://www.nartac.com/Products/IISCrypto) which (after a reboot) disables weak cipher suites and ensures that the correct key exchange mechanisms are used on your servers and clients. Note this software doesn’t just apply to IIS (Internet Information Services) but also Remote Desktop and any other Microsoft technology that makes use of schannel.

Although it takes a little while longer you can also examine the registry (see https://www.nartac.com/Support/IISCrypto/FAQ) and deploy a Group Policy to apply the same settings to your machines.

If you can I would suggest you opt for the PCI 3.1 template (which also culls TLS1.0 support) however as I found out you may have to resort to the ‘Best Practices’ which keeps TLS1.0 enabled and in turn allows things like 802.1x EAPOL and older versions of Microsoft SQL Server to work. Really is worth doing extensive testing with all of your applications (network services included!) before you go and roll this tool out to your full environment!

SSL/TLS: Certificate Signed Using A Weak Signature Algorithm

In this case we are looking at the self signed Remote Desktop Protocol certificate which just so happens to be SHA1. To resolve this issue have a look at this blog post – https://www.darkoperator.com/blog/2015/3/26/rdp-tls-certificate-deployment-using-gpo which covers in great detail how to use an Active Directory Certificate Services Server to issue SHA256 certificates to your machines to use with Remote Desktop.