Articles by 'Timothy Karl'

Blog Author - Timothy Karl

Tim has over 10 years’ experience in the design, development, and deployment of Windows infrastructure technologies. His experience also includes the high-level design of complex thin client and server-based computing environments. He is highly fluent in all aspects of Windows and Citrix infrastructure technologies.

By Timothy Karl, Posted in Infrastructure, Support

Today, over 85% of organizations worldwide operate on Microsoft Active Directory. In many cases, Active Directory has been in place for decades and has not been well maintained for security posture. Hackers often target Active Directory as an easy way for gaining access to a customer’s environment. Gotham has developed an Active Directory Security Risk Assessment offering to provide specific actionable guidance to mitigate security risks in your Active Directory environment. The assessment focuses on... read more.

  • March 31, 2021

By Timothy Karl, Posted in Infrastructure, Security

Microsoft Windows 7 and Windows Server 2008 reached end of life on January 14, 2020. This means that Microsoft will no longer be releasing free security patches, updates, or support when something goes wrong. Although these operating systems won’t instantly stop working or become security risks overnight, there are risks with staying on these operating systems for an extended period of time. What happens if I stay on these operating systems? There is a huge risk of being exploited by cyber crimina... read more.

  • January 16, 2020

By Timothy Karl, Posted in Infrastructure, Security

On December 17, 2019, Citrix released a critical advisory regarding a vulnerability that allows for remote code execution: CVE-2019-19781 - Vulnerability in Citrix Application Delivery Controller and Citrix Gateway (https://support.citrix.com/article/CTX267027). The vulnerability exploits a directory traversal attack on the /vpn directory on the NetScaler. It allows for remote execution of code under the user nobody. Gotham previously alerted customers to this vulnerability. Citrix plans to release a perma... read more.

  • January 15, 2020

By Timothy Karl, Posted in Infrastructure, Virtualization

Microsoft Teams is a unified communication and collaboration platform that combines chat, audio calling, video conferencing, file storage, and application integration. It is a replacement for Skype for Business, which will reach end of life in July 2021. It comes with a company's Office 365 subscription, depending on your licensing plan, and can integrate with non-Microsoft products. The following Office 365 subscription licensing plans enable users for Teams: Image via Microsoft. By hosting Micros... read more.

  • December 23, 2019

By Timothy Karl, Posted in Infrastructure, Support

A common issue I see in Citrix Virtual Apps and Desktops deployments is users who are unable to print to their local printers from Mac and Linux clients when using Citrix Universal Printer Driver (UPD ). The good news is, it is a very simple fix! Citrix UPD relies on a series of printer drivers to be installed on the VDA machine. When a client printer is mapped into a session, it is automatically mapped to one of these three drivers: The Citrix Universal Printer and Citrix XPS Universal Printer drivers... read more.

  • September 06, 2019

By Timothy Karl, Posted in Infrastructure, Virtualization

As of August 2018, the Citrix Workspace app has replaced Citrix Receiver. The Citrix Workspace app securely aggregates all of your applications and data, whether on-premises or in the cloud, from any device into a single unified app. Below is a sample screenshot of the Workspace app: In order to take full advantage of the Workspace app, it needs to be integrated with the Workspace service which is a fundamental component of Citrix Cloud. The service is responsible for aggregating and delivering all of yo... read more.

  • June 21, 2019

By Timothy Karl, Posted in Infrastructure

Global Server Load Balancing (GSLB) is a feature of NetScaler that provides for disaster recovery and continuous availability of applications when there are points of failure in a wide area network (WAN). GSLB can balance application loads across data centers by directing client requests to the closest or best-performing data center, or in the case of an outage, any surviving data center. In a typical GSLB deployment, proximity-based load balancing methods are used to determine the location of the client a... read more.

  • June 28, 2018

By Timothy Karl, Posted in

One of the most important responsibilities for a Citrix Administrator is to maintain the health of Citrix Virtual Desktop Agents (VDA). Registration and session launch issues can lead to unavailable desktops, disconnected sessions, and unusable environments. When virtual desktops are not available, it leads to a loss of employee productivity and incurred costs to the business. To help maintain the health of Citrix VDAs, Citrix now offers a VDA Health Check as part of their Smart Check toolset. Smart Check... read more.

  • April 12, 2018

By Timothy Karl, Posted in Infrastructure, Virtualization

As our customers renewed their Citrix licensing this past year, some have seen SD-WAN in their list of available licenses. A question I often get asked is what is this SD-WAN license and how did I use it? There are two components to Citrix NetScaler SD-WAN: WAN Optimization and Virtual WAN.   WAN Optimization has been a part of the Citrix product portfolio for years, since the acquisition of Orbital Data in 2006. It is basically a network optimization device that provides QoS functionality. The tec... read more.

  • December 21, 2017

By Timothy Karl, Posted in Uncategorized

Starting with Presentation Server 4.5, Citrix introduced a feature called Proximity Printing. This feature allows an administrator to control the assignment of network printers based on a user’s location using a combination of session printer policies and filters, e.g., mapping a network printer based on a client IP address, or a range of client IP addresses. With XenApp 6 and later versions, the client IP address filter changed, and the option to enter an IP address range was removed. The only option wi... read more.

  • July 09, 2015