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Windows 10 on the Intel DBZ68 motherboard

January 27, 2018 Leave a comment

Yesterday I needed to install Windows 10 on a now 7 year old Intel DBZ68 motherboard, as the previous Windows 7 installation in the classroom was acting weirdly. Before I did that however, I tried to update the board’s firmware using the Windows based executable available on Intel’s site, as I’ve done with other Intel boards many times before. Unfortunately, a lot like the experiences I previously mentioned here, the firmware wouldn’t update using the Windows tool. I left it for later and proceeded to install Windows 10 on the machine.

Windows 10 itself runs quite nicely on this older board, helped no doubt by the SSD and Core i5 chip. The biggest snag I had was trying to use the onboard HD graphics to power a 3rd monitor. Windows 10 includes an “inbox” driver for 2nd and 3rd gen Intel Core CPU’s with integrated graphics, but Windows wouldn’t recognise and install the adapter for some reason. Trying to install the driver simply ended with the PC hard locking and needing a full power cycle to restore to working order. After futzing around for a while, I decided to do the firmware update, using a flash drive, Rufus and the last BIOS file on Intel’s site – you have to flash the firmware using IFLASH from FreeDOS, hence using Rufus to create a bootable USB drive with FreeDOS.

The 0014 BIOS that came on the board simply wouldn’t update via Windows and as linked in the previous article, it doesn’t let you use the F7 key during startup to do an update either. Thankfully the update went quickly and without any hitches. It seems the graphics adapter ROM was updated in BIOS 0027, changes which obviously carried over into the final 0043 firmware. Windows 10 needs the updated firmware for the adapter to be recognised correctly.

Back in Windows I simply had to select Update Driver on the unknown graphics adapter, choose from a list of devices already on the PC and let Windows find the best match. Seconds later the driver was installed and the 3rd monitor sprang to life.

The PC should continue to work for a few more years until eventually it gets replaced. The motherboard was a very nice one for its time, but lacks many modern useful features such as UEFI capable network boot, a graphical UEFI, UEFI Secure Boot etc. Still, it goes to show that with firmware updates and a little patience, even older hardware can still be relevant and useful in this day and age and doesn’t need to be carted off for recycling just yet. There’s plenty of power still left in Sandybridge era hardware, depending on your usage scenario of course.

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Adding Office365 licenses to new users via PowerShell

December 12, 2017 Leave a comment

One of the tasks any school has to do each year is remove old students and add new ones. Using the built-in CSVDE tool, you can bulk import users into Active Directory very easily. Once there, they’ll get synchronised up to Office 365 (provided they are in an OU that is selected for sync) as new users. Good stuff! The only problem is that all those new users do not have licenses assigned to them in Office 365, which means they can’t use anything. You could manually assign a license to each user individually using the Office 365 website, but that will take hours, if not days if you have a huge number of students to license. Thankfully, there is a better way: PowerShell.

A very small script that is only 11 lines long will load usernames from a seperate CSV file and assign licenses to users based on that CSV file. Here is the script:

Import-Module MSOnline
Connect-MsolService
$users = Import-Csv “C:\Users\Username\Desktop\2018.csv” -delimiter “,”
foreach ($user in $users)
{
$upn=$user.UserPrincipalName
$usagelocation=$user.UsageLocation
$SKU=$user.SKU
Set-MsolUser -UserPrincipalName $upn -UsageLocation $usagelocation
Set-MsolUserLicense -UserPrincipalName $upn -AddLicenses $sku
}

Essentially, the script connects to Office 365 with your credentials (use an admin level account to connect). Change the location of the CSV file to your own location. The contents of the CSV file is simple, just 3 columns in total – column 1 is the User Principal Name of each student, column 2 is the 2 digit country code of your country and column 3 is the product license you want to assign to the student. Name the 1st cell in each column UserPrincipalName, UsageLocation and SKU respectively. You can find out what the exact license names for your Office 365 tenancy are by connecting to it as follows in PowerShell:

Import-Module MSOnline
Connect-MsolService
Get-MsolAccountSku

You will end up with a list of license options for your tenancy, with a name along the lines of tenantname:STANDARDPACK. Copy and paste your desired license name into your CSV file for each user you want that license for.

Run the above script when you are happy with your CSV import file and if all goes well, a few minutes later all the users in Office 365 will have been correctly licensed.

You could get more complicated so that each license if configured with certain options disabled etc, but that involved extra complexity in your script. Keep it simple I reckon.

Flashing all the Firmwares

November 26, 2017 Leave a comment

In the not so distant past, updating an electronic device’s firmware was either impossible or carried a great many risks. In the slightly slower paced world back then, we didn’t complain too much, perhaps because devices shipped with by and large stable firmware that had spent lots of time in development and ended up being quite polished. In today’s break neck paced world, nothing is ever done and devices are often shipped as quickly as possible, with the promise to update the firmware and improve matters as time goes on.

For the manufacturers who adhere to this promise and regularly put out updated firmware, well done! You deserve big kudos for doing so. Sadly this state of affairs is more the exception than the rule. Far too often a device is shipped to market with initial firmware that gets updated maybe once or twice, only to be abandoned by the manufacturer who has moved onto the next bright and shiny gadget. The most obvious example of this is the mess that most Android based phones have gotten themselves into.

Sometimes firmware just operates low level hardware like the control board on a DVD burner for example. Other times it’s both that and a user interface/operating system all rolled into one – think of the web interface you use to control a home router for example. Sometimes the update just fixes bugs and adds stability, other times it does that and adds new features or updates the user interface – think updated PC UEFI or 3rd party router firmwares.

I promise there’s a point to all this rambling. The recent school holidays afforded me a chance to update firmware on a whole range of devices in my school. Network switches, ADSL routers, CCTV Cameras and the attached NVR as well as a few other odds and ends. HP deserves a special shout out here for their lengthy firmware life for older model switches. Whilst they had no reason to do, HP did keep updating the firmware of certain switches for a good number of years, which at least extended the useful life of these devices.

Sadly on the old 2610 series HP didn’t remove the Java based web interface, but the last available firmware did at least sign the binaries so that there’s one less warning when you connect. For the 2620 series, HP back ported the new UI from their modern Aruba switches, which has lead to a nice consistent interface across 3 different switch generations we own. If you’ve ever used HP’s legacy interface on the 2620 and other similar generation models, you’ll know how ugly and painful that interface was to use.

The Dahua CCTV system we used though was another story. For one thing, the fixed bullet camera we were sold appeared to have been very quickly replaced by Dahua, so there’s no new firmware beyond 2015. The fixed dome cameras did better however, with a firmware from only a few months ago. The NVR also had a much later firmware available. I flashed the NVR first, only for all hell to break out after the reboot. A large portion of the cameras refused to connect to the device after the update. Whilst most of the settings seemed to have been preserved during the update, too many little things seemed to have been disturbed. The next thing I did was to update the dome cameras one by one. When that still didn’t help, I deleted and re-added all the cameras to the NVR. To my relief, this sorted the problem and we were able to go back to using the system.

That being said, there has been some cases of the cameras displaying corrupted green screens, though that hasn’t lasted long and only seemed to be affecting 1-2 cameras. Those devices might just need to be flashed again for proper stability, but it’s still not how it’s supposed to be. Alternatively, I will check for the next available update and flash that to the cameras, hoping it solves the problem on those cameras with issues.

I still have my main server’s firmware to flash which I plan to do in the next school holidays. Intel has discontinued the S2600GZ system, but at least they also still make firmware available. That system is unlikely to get any more updates in the future, but at least it had a decent lifespan.

My suggestion when it comes to firmware updating is to flash everything you have with the latest available firmware, unless it is a completely critical core device that you cannot have any downtime or potential problems. Rather safe than sorry and sometimes an update is the only way to fix things. There’s also the option of 3rd party firmware on some devices, but that’s a whole different post.

DHCP Relay: the basics

November 26, 2017 Leave a comment

If you run a small flat network, DHCP just magically works once it is set up. Devices get their addresses, devices communicate, everything works and everyone is happy. The moment you partition the network with VLANS however, things change. Devices in the additional segment(s) no longer receive DHCP packets. There are 3 options available to rectify this issue:

  1. Manually configure static IP addresses. Painful but will work.
  2. Set up a DHCP server per additional VLAN. Lot of duplicated work and if you aren’t careful, DHCP packets can end up crossing VLANS, causing havoc with devices.
  3. Use DHCP relay to centralise IP address issuing from one central server.
  4. I’ve just recently configured DHCP relay at my school and it’s working well. Getting it set up is a tad tricky, but once you understand how it works, it’s quite straight forward. Here is a guide on how to do it on a network that runs Aruba switches and Windows 2012 R2 DHCP server.

    It should be noted that in order for this to work, you need a core switch that is capable of IP routing. Layer 3 switches will do this, as well some higher end Layer 2 switches from Aruba – the 2530 and 2540 models spring to mind. If you don’t have a routing capable switch in your network, you are going to need a router to be connected to each VLAN to do the job instead. Your VLANS must also be set up correctly with untagged and tagged ports for this to work.

Firstly, decide on the IP ranges you want for your additional VLANS. Try to ensure you have enough space so that you don’t need to redo the scope later on.

Next, create these scopes with all the necessary extra bits in the Windows DHCP management console, but do not activate them when asked at the end of the wizard. Leave them deactivated for the time being.

On your core Aruba switch, assign an IP address to every VLAN that you want to use DHCP relay on. Make sure that this IP matches the range of your DHCP server scope, but that the address doesn’t conflict with something in the range.

Next, enable IP routing on the core switch:

conf t
ip routing
wr mem

Next, add the IP helper address to each VLAN you want to use DHCP on. On the switch’s command line, type the following:

conf t (if starting from scratch, not needed if you are still carrying on from the above step)
vlan 20 ip helper-address 192.168.0.10
wr mem


Substitute VLAN 20 for each additional VLAN ID and 192.168.0.10 for your DHCP server.

On each of your edge switches, do not give the switch an IP in any VLAN except your main or management VLAN that the core switch also resides in. Point each edge switch’s IP default gateway address to the core switch’s IP address.

On your Windows DHCP server, you will need to add some static routes to the server unless its default gateway is pointed to the core switch. Odds are that the server isn’t pointed to the core switch but rather to a firewall for internet access, so the routes will need to be added manually. Open up a command prompt and type the following:

route –p add 172.16.0.0 mask 255.255.254.0 192.168.0.75

Repeat the above command for each VLAN you want DHCP on. Substitute 172.16.0.0 with your own network, mask 255.255.254.0 with the correct subnet mask and 192.168.0.75 with your own core switch IP.

Lastly, activate the scope(s) in the Windows DHCP console. You can test things out by using a client PC in each VLAN and releasing and refreshing the IP address. You should be obtaining an address that is correct for each VLAN and there should be no spill over between the VLANS that will cause network chaos. You should be able to see the clients appearing in the Address Lease section of each DHCP scope.

Hyper-V bug in Windows 10 v1703

November 4, 2017 Leave a comment

I encountered a nasty little bug in Windows 10 v1703 Hyper-V a.k.a the Creators Update this past week. If you create a Generation 2 virtual machine and try to PXE boot that VM, regardless of whether it’s on an internal switch or bridged to an external network, you will end up with the following screen:

Hyper-

No matter what you do, the VM will not PXE boot. Disabling Secure Boot and fiddling with other options will not help. I was very confused by this problem, as I’ve PXE booted generation 2 clients before. A few searches later revealed this link which explains the problem in greater detail.

In short, the only answer is to either downgrade to Windows 10 1607 or upgrade to Windows 10 1709, which was released little over 2 weeks ago. Generation 1 VM’s are not affected and you can PXE boot them successfully, but they do have a higher overhead than gen 2 VM’s. How this bug crept into Hyper-V is curious to say the least, but at least there’s a definitive fix. I should add that the bug has not been fixed as of the latest cumulative update for 1703 and is probably unlikely to be fixed, given the way Microsoft now releases Windows 10 updates/upgrades.

Goodbye Exchange 2007

It’s been a while since I last posted here. Life has been super hectic and finding free time to write something coherent has been harder than I thought it would be. I’ve also seen that my last post was actually my 200th post, which in the grand scheme of things is a pretty nice milestone considering how eratic I’ve been with posting over the years.

Anyway, I’m going to keep this one short and sweet. I’m posting a screenshot I made as I was finishing the removal of Exchange 2007 from our network ±4 months ago. Our mail platform has been running successfully on Office 365 since that time, with only the very odd head scratching moment causing some minor grief. Staff have more or less settled down into using the new platform, though they probably still need a lot more time to become fully familiar with the interface. SPAM suppression seems to be working well, though I’m not sure how many staff are actually checking their junk folders for legit mail that is incorrectly marked as junk.

I must say that the un-install process went very smoothly, it just took a long time as per the screenshot below. I chose to do things properly instead of just trashing the VM, which would have been a lot quicker. The removal process removes a lot of stuff from Active Directory, though there is still quite a bit of cruft left behind.

Categories: Software Tags:

Being a good net citizen: SPF, DKIM and DMARC records

Spam and Phishing emails are some of the more visible scourges of the modern internet. No one enjoys opening up their mailbox and seeing junk clutter up the place, or seeing a mail that tempts you to enter credentials somewhere because it looks legitimate. The war against Spam and Phishing is an on-going battle, with many tools deployed to try and keep a user’s inbox clean.

If you own or manage a domain on the internet and that domain makes use of email, it’s only right to be a good net citizen and set up SPF, DKIM and DMARC records. Together those 3 make a 3 pronged fork that can be stabbed into the heart of junk mail, but they each do a slightly different thing. Let’s take a look at them:

SPF essentially denotes who is allowed to send mail for your domain. Anything that doesn’t match the details in the record is to be considered an attempt to spoof your domain and should ideally be rejected, provided the record is set up as such. If you have a small domain with simple records, SPF is incredibly easy to set up. It becomes harder if you are a giant corporation or have lots of mail being sent from third party bulk mailers, but even those use case scenarios can be brought into line so that you have a valid SPF record. If Microsoft, Google and others can do it, why can’t we?

DKIM is a little trickier. DKIM enabled servers sign outgoing mail with a digital signature and lets receiving servers validate the signature using the published key in the DKIM DNS record. This way, mail can be verified as having been sent from domain abcdefg.com because the signature can be verified by consulting the DKIM record in abcdefg.com’s domain. If the validation fails it’s either because the mail was forged or the message modified on route. Since spammers aren’t running your mail server, they can’t validly sign outgoing messages with your private key, so when a destination server checks the signature, the check will fail.

DMARC sits on top of SPF and DKIM. While SPF contains syntax for what to do when mail fails a check, DKIM does not. DMARC essentially tells a recipient mail server what do with those mail if they fail the SPF/DKIM checks. Mail can either be allowed through to be processed as the destination sees fit, sent to the Spam/Junk folder or rejected outright. Set to reject mode and along with an –all syntax in SPF, this will ensure that spammers cannot spoof mail from your domain (in theory)

It’s not perfect though. In order for the 3 records to be effective, the destination mail server needs to check the records. If the server doesn’t and simply accepts mail as is, junk mail will make it into the inbox from forged senders. The records also don’t help if a spammer compromises a legitimate account in a domain with all 3 records, as when the mail is sent out via that domain, it will pass all checks on the destination end, as it was sent from a domain with valid records. To prevent this, you’ll need to set up rules to detect outgoing spam and block it from being sent. Each mail server will have different instructions on how to do this.

Office 365 and G-Suite all include records for SPF, while DKIM takes a few more steps to set up in Office 365. G-Suite also supports DKIM as far as I know, but since I don’t use the product, I don’t know how hard or easy it is to set up.

While nothing is ever perfect in the war against spammers, a huge amount of junk mail could be stopped cold if more domains published valid SPF, DKIM and DMARC records. Banks and financial institutes that are a favourite target of fraudsters could save themselves a lot of grief by having destination domains reject all mail that isn’t legit. IP block lists and content filtering will remain an important part of the game, but if more junk mail could be stopped at the edge before being accepted and processed, the better off the entire internet will become.

Categories: Internet, My tips and tricks Tags: , ,