Exam prep & experience: VMware Certified Advanced Professional 6 – Data Center Virtualization Deployment Exam (VCAP6-DCV Deploy)

2 Replies

TL;DR: I have passed the VCAP6-DCV Deploy exam today. :) I want to thank Fred, Dominik, Frank and Jens-Henrik for kicking my ass. Without you, I would have taken the VCP 6.5 delta exam. Thank you!

As often, the whole thing started with a tweet. A tweet about my expiring VMware Certified Professional (VCP) certification.

Time to prepare the VCP-DCV 6.5 Delta. Otherwise my VCP expires in a couple of months.
— Patrick Terlisten (@PTerlisten) June 30, 2018

To my surprise, several of my followers recommended to go for the VCAP6-DCV Deployment instead. Okay, so many smart people can’t be wrong.… Read more

The one stop solution for backup and DR: Vembu BDR Suite

Leave a reply

I have worked with a lot of backup software products during my career, but for the last years I have primarily worked with MicroFocus Data Protector (former HP OmniBack, HP Data Protector, or HPE Data Protector), and Veeam Backup & Replication. Data Protector was a great solution for traditional server environments, or when UNIX (HP-UX, AIX, Solaris etc.) compatibility was required. Features like Zero Downtime Backups, LAN-free or Direct SAN backups were available for many years. But their code quality has suffered severely in the recent years. The product no longer seemed like a one-stop shop.… Read more

Backup from a secondary HPE 3PAR StoreServ array with Veeam Backup & Replication

Leave a reply

When taking a backup with Veeam Backup & Replication, a VM snapshot is created to get a consistent state of the VM. The snapshot is taken prior the backup, and it is removed after the successful backup of the VM. The snapshot grows during its lifetime, and you should keep in mind, that you need some free space in the datastore for snapshots. This can be a problem, especially in case of multiple VM backups at a time, and if the VMs share the same datastore.

Benefit of storage snapshots

If your underlying storage supports the creation of storage snapshots, Veeam offers an additional way to create a consistent state of the VMs.… Read more

CloudFlare API v4 and Fail2ban: Fixing the unban action

2 Replies

In January 2017, I wrote an article about how to protect your WordPress blog using the WP Fail2Ban plugin, fail2ban on your Linux/ FreeBSD host, and CloudFlare. Back then, the fail2ban was using the CloudFlare API V1, which was already deprecated since November 2016.

Although the actions were updated later to use CloudFlare API V4, I still had problems with the unbaning of IP addresses. IP addresses were banned, but the unban action failed.

This is the unban action, which is included in fail2ban (taken from fail2ban-0.10.3.1 which is shipped with FreeBSD 11.1-RELEASE-p10):

actionunban = curl -s -o /dev/null -X DELETE -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \
            https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules/$(curl -s -X GET -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \
            'https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules?mode=block&configuration_target=ip&configuration_value=<ip>&page=1&per_page=1' | cut -d'"' -f6)

actionunban = curl -s -o /dev/null -X DELETE -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \

https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules/$(curl -s -X GET -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \

'https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules?mode=block&configuration_target=ip&configuration_value=<ip>&page=1&per_page=1' | cut -d'"' -f6)

And this is the unban action, which finally solved this issue:

actionunban = curl -s -o /dev/null -X DELETE -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \
            https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules/$(curl -s -X GET -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \
            'https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules?mode=block&configuration_target=ip&configuration_value=<ip>&page=1&per_page=1' | tr -d '\n' | cut -d'"' -f6)

actionunban = curl -s -o /dev/null -X DELETE -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \

https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules/$(curl -s -X GET -H 'X-Auth-Email: <cfuser>' -H 'X-Auth-Key: <cftoken>' \

'https://api.cloudflare.com/client/v4/user/firewall/access_rules/rules?mode=block&configuration_target=ip&configuration_value=<ip>&page=1&per_page=1' | tr -d '\n' | cut -d'"' -f6)

I found the solution at serverfault.com.… Read more

Windows Network Policy Server (NPS) server won’t log failed login attempts

Leave a reply

This is just a short, but interesting blog post. When you have to troubleshoot authentication failures in a network that uses Windows Network Policy Server (NPS), the Windows event log is absolutely indispensable. The event log offers everything you need. The success and failure event log entries include all necessary information to get you back on track. If failure events would be logged…

Today, I was playing with Alcatel-Lucent Enterprise OmniSwitches and Access Guardian in my lab. Access Guardian refers to the some OmniSwitch security functions that work together to provide a dynamic, proactive network security solution:

Universal Network Profile (UNP)
Authentication, Authorization, and Accounting (AAA)
Bring Your Own Device (BYOD)
Captive Portal
Quarantine Manager and Remediation (QMR)

I have planned to publish some blog posts about Access Guardian in the future, because it is a pretty interesting topic.… Read more

Replace SSL certificates on Citrix NetScaler using the CLI

Leave a reply

Sometimes you have to replace SSL certificates instead of updating them, e.g. if you switch from a web server SSL certificate to a wildcard certificate. The latter was my job today. In my case, the SSL certificate was used in a Microsoft Exchange 2016 deployment, and the NetScaler configuration was using multiple virtual servers. I’m using this little script for my NetScaler/ Exchange deployments.

When using multiple virtual servers, replacing a SSL certificate using the GUI can be challenging, because you have to navigate multiple sites, click here, click there etc. Using the CLI, the same task is much easier und faster.… Read more

Bypass stateful firewall on a Sophos XG

Leave a reply

Usually, bypassing a firewall is not the best idea. But sometimes you have to. One case, where you want to bypass a firewall, is asymmetric routing.

What is asymmetric routing? Imagine a scenario with two routers on the same network. One router offeres access to the internet, the other router provides access to other sites with site-2-site VPN tunnels.

Host 1 uses R1 as default gateway. R1 has static routes configured to the networks reachable over the VPN, or it has learned them dynamically using a routing protocol from R2. A packet from host 1 arrives at R1, is routed to R2, and is sent over the VPN tunnel.… Read more

Veeam backups fails because of time differences

Leave a reply

Last week I had an interesting incident at a customer. The customer reported that one of multiple Veeam backup jobs jobs constantly failed.

The backup job included two VMs, and the backup of one of these VMs failed with this error:

Error: Failed to open VDDK disk [[VMDS-SAS-01] VMDC1/VMDC1_1.vmdk] ( is read-only mode - [true] ) 
Failed to open virtual disk Logon attempt with parameters [VC/ESX: [vcenter.domain.tld];Port: 443;Login: 
[AD\Administrator];VMX Spec: [moref=vm-59];Snapshot mor: [snapshot-20226];Transports: [san];Read Only: [true]]
failed because of the following errors: Failed to open virtual disk Logon attempt with parameters 
VC/ESX: [vcenter.domain.tld];Port: 443;Login: [AD\Administrator

Error: Failed to open VDDK disk [[VMDS-SAS-01] VMDC1/VMDC1_1.vmdk] ( is read-only mode - [true] )

Failed to open virtual disk Logon attempt with parameters [VC/ESX: [vcenter.domain.tld];Port: 443;Login:

[AD\Administrator];VMX Spec: [moref=vm-59];Snapshot mor: [snapshot-20226];Transports: [san];Read Only: [true]]

failed because of the following errors: Failed to open virtual disk Logon attempt with parameters

VC/ESX: [vcenter.domain.tld];Port: 443;Login: [AD\Administrator

The verified the used credentials for that job, but re-entering the password does not solved the issue.… Read more

DOT1X authentication failed on HPE OfficeConnect 1920 switches

Leave a reply

The last two days, I have supported a customer during the implementation of 802.1x. His network consisted of HPE/ Aruba and some HPE Comware switches. Two RADIUS server with appropriate policies was already in place. The configuration and test with the ProVision based switches was pretty simple. The Comware based switches, in this case OfficeConnect 1920, made me more headache.

The customer had already mac authentication running, so all I had to do, was to enable 802.1x on the desired ports of the OfficeConnect 1920. The laptop, which I used to test the connection, was already configured and worked flawless if I plugged it into a 802.1x enabled port on a ProVision based switch.… Read more

HPE Networking expert level certifications

Leave a reply

A couple of days ago, I took the HP0-Y47 exam “Deploying HP FlexNetwork Core Technologies”. It was one of two required exams to achive the HPE ASE – Data Center Network Integrator V1, and the HP ASE – FlexNetwork Integrator V1 certification. It was a long planned upgrade to my HP ATP certification, and it is a necessary certification for the HPE partner status of my employer.

You might find it confusing that I’m talking about an HP ASE and a HPE ASE. That is not a typo. The HP ASE was released prior the HP/ HPE split. The HPE ASE was released after the split in HP and HPE.

The HP/ HPE ATP is a professional level certification, comparable to the Cisco Certified Network Associate (CCNA).… Read more

vcloudnine.de

… virtualization on cloud 9

Exam prep & experience: VMware Certified Advanced Professional 6 – Data Center Virtualization Deployment Exam (VCAP6-DCV Deploy)

The one stop solution for backup and DR: Vembu BDR Suite

Backup from a secondary HPE 3PAR StoreServ array with Veeam Backup & Replication

CloudFlare API v4 and Fail2ban: Fixing the unban action

Windows Network Policy Server (NPS) server won’t log failed login attempts

Replace SSL certificates on Citrix NetScaler using the CLI

Bypass stateful firewall on a Sophos XG

Veeam backups fails because of time differences

DOT1X authentication failed on HPE OfficeConnect 1920 switches

HPE Networking expert level certifications