Notes for a 2-Tier Microsoft Windows PKI

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Implementing a public key infrastructure (PKI) is a recurring task for me. More and more customers tend to implement a PKI in their environment. Mostly not to increase security, rather then to get rid of browser warnings because of self-signed certificates, to secure intra-org email communication with S/MIME, or to sign Microsoft Office macros.

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What is a 2-tier PKI?

Why is a multi-tier PKI hierarchy a good idea? Such a hierarchy typically consits of a root Certificate Authority (CA), and an issuing CA. Sometimes you see a 3-tier hierarchy, in which a root CA, a sub CA and an issuing CA are tied together in a chain of trust.… Read more

Veeam B&R: “Rescan of Manually Added” failed

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I got this error in a new deployment of Veeam Backup & Replication 9.5 Update 4. The error occured every day at 9 pm.

The solution to this issue is pretty simple.… Read more

Windows NPS – Authentication failed with error code 16

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Today, a customer called me and reported, on the first sight, a pretty weired error: Only Windows clients were unable to login into a WPA2-Enterprise wireless network. The setup itself was pretty simple: Cisco Meraki WiFi access points, a Windows Network Protection Server (NPS) on a Windows Server 2016 Domain Controller, and a Sophos SG 125 was acting as DHCP for different WiFi networks.

Windows clients failed to authenticate, but Apple iOS, Android, and even Windows 10 Tablets had no problem.

The following error was logged into the Windows Security event log.

… Read more

Help Vembu and win a gift card!

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Vembu Technologies was founded in 2002, and with 60.000 customers and more than 4000 partners, Vembu is a leading provider with a comprehensive portfolio of software products and cloud services to small and medium businesses.

Backup is important. There is no reason to have no backup. According to an infographic published by Clutch Research at the World Backup Day 2017, 60% of all SMBs that lost all their data will shutdown within 6 months after the data loss. Pretty bad, isn’t it?

When I talk to SMB customers, most of them complain about the costs of backups. You need software, you need the hardware, and depending on the type of used hardware, you need media.… Read more

Client-specific message size limits – or the reason why iOS won’t sent emails

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Last week, a customer complained that he could not send emails with pictures with the native iOS email app. He attached three, four or five pictures to an emails, pushed the send button and instantly an error was displayed.

We checked the different connectors as well as the organizational limit for messages. The test mails were between 10 to 20 MB, and the message size limit was much higher.

The cross-check with Outlook Web Access indicated, that the issue was not a configured limit on one of the Exchange connectors. Instead, a quick search directed us towards the client-specific message size limits.… Read more

Veeam Backup & Replication: Backup of Microsoft Active Directory Domain Controller VMs

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To backup a virtual machine, Veeam Backup & Replication needs two permissions:

  • permission to access and backup the VM, as well as the
  • permission to do specific tasks inside the VM

to guarantee a consistent backup. The former persmission is granted by the user account that is used to access the VMware vCenter server (sorry for the VMW focust at this point). Usually, this account has the Administrator role granted at the vCenter Server level. The latter permission is granted by a user account that has permissions inside the guest operating system.

Something I often see in customer environments is the usage of the Domain Administrator account.… Read more

Veeam and StoreOnce: Wrong FC-HBA driver/ firmware causes Windows BSoD

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One of my customers bought a very nice new backup solution, which consists of a

  • HPE StoreOnce 5100 with ~ 144 TB usable capacity,
  • and a new HPE ProLiant DL380 Gen10 with Windows Server 2016

as new backup server. StoreOnce and backup server will be connected with 8 Gb Fibre-Channel and 10 GbE to the existing network and SAN. Veeam Backup & Replication 9.5 U3a is already in use, as well as VMware vSphere 6.5 Enterprise Plus. The backend storage is a HPE 3PAR 8200.

This setup allows the usage of Catalyst over Fibre-Channel together with Veeam Storage Snapshots, and this was intended to use.

I wrote about a similar setup some month ago: Backup from a secondary HPE 3PAR StoreServ array with Veeam Backup & Replication.… Read more

Out-of-Office replies are dropped due to empty MAIL FROM

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Today I had an interesting support call. A customer noticed that Out-of-Office replies were not received by recipients, even though the OoO option were enabled for internal and external recipients. Internal recipients got the OoO reply, but none of the external recipients.

The Message Tracking Log is a good point to start. I quickly discovered that the Exchange server was unable to send the OoO mails. You can use the eventid FAIL to get a list of all failed messages.

Very interesting was the RecipientStatus of a failed mail.

550 Requested action not taken: mailbox unavailable  is a pretty interesting error when sending mails over a mail relay of your ISP.… Read more

Database Availability Group (DAG) witness is in a failed state

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As part of a maintenance job I had to update a 2-node Exchange Database Availability Group and a file-share witness server.

After the installation of Windows updates on the witness server and the obligatory reboot, the witness left in a failed state.

… Read more

Vembu BDR Suite v4.0 is now generally available

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Vembu Technologies was founded in 2002, and with 60.000 customers and more than 4000 partners, Vembu is a leading provider with a comprehensive portfolio of software products and cloud services to small and medium businesses.

Last week, Vembu has announced the availability of Vembu BDR Suite v4.0! Vembu’s new release is all about maintaining business continuity and ensuring high availability. Apart from new features, this release features significant enhancements and bug fixes that are geared towards performance improvement.

The Vembu BDR Suite

The Vembu BDR Suite is an one stop solution to all your backup and disaster recovery needs.… Read more