Blog.JeffGatto.com

Validating MD5 Checksum

In Windows, you can use the “certutil -hashfile” command to validate an MD5 checksum of a file you’ve downloaded. First, open PowerShell and navigate to the directory containing the file you downloaded. Next, run:

certutil -hashfile <file_name> MD5

The response will contain the MD5 hash value of the file. Check that value against the known good MD5 value.

Microsoft Docs: https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/certutil




Leadership

The following is from John C. Maxwell.

Leadership is influence.

Leadership is the ability to obtain followers.

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I took a walk today…

… and this is what I found.

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NetApp (NCSA) NS0-145

I recently completed a 7 hour (47 video) CBTNuggets.com training course for NetApp Certified Storage Associate (NCSA) NS0-145. Below is the course content geared towards successful completion of the NS0-145 NetApp Certification. I highly recommend that you take the time to review all that CBTNuggets has to offer. I will post my course notes in short order.

NetApp Certified Storage Associate (NCSA) NS0-145
NetApp is a leader in IT storage. This course not only covers the fundamentals of storage and cloud computing, it also provides detailed step-by-step guidance on installing, configuring, and maintaining a NetApp Data ONTAP (7-Mode or Clustered) environment. This course also completely prepares students for the challenging NCSA exam. NetApp Certified Storage Associates demonstrate a basic understanding of NetApp storage systems and Data ONTAP administration and management solutions. Students can understand the features and functions of 7-Mode and clustered Data ONTAP, and are able to perform basic administration of NetApp storage controllers running the Data ONTAP® operating system in NFS and Windows® (CIFS) multi-protocol environments.

  1. NCSA Course Intro
  2. Introduction to Data Storage
  3. DAS vs. NAS vs. SAN
  4. Exciting New Storage Technologies
  5. Server Virtualization
  6. Data Networks Fundamentals
  7. Cloud Fundamentals
  8. Scared of the Cloud?
  9. Introducing Flash Storage
  10. Flash Storage Components and Performance
  11. Solid State Technologies
  12. Flash Endurance
  13. Major Industry Trends Per NetApp
  14. OnCommand Management Software
  15. Clustered Data ONTAP
  16. Data ONTAP 7-Mode (more…)




Exchange Server 2013

Exchange Server 2013 is up and running with mail flowing!, more to come.

My lab domain now consists of:
(2) WinServer 2012 – Domain Controllers (AD DS, DNS, DHCP)
(2) WinServer 2012 – Running Exchange Server 2012
(1) WinServer 2012 – IIS Server
(2) Win 7 Clients – Outlook 2013

So many PowerShell cmdlets, so little time.
Some of the basics I will be posting about:

  • Add-PSSnapin Microsoft.Exchange.Management.PowerShell.Snapin;
  • Enter-PSSession <server>
  • Get-ECPVirtualDirectory | Format-List
  • Get, New, Remove – Mailbox
  • Get, New, Remove -MailUser
  • Get-ServerHealth
  • Test-ServiceHealth




Under Construction

This blog is currently under construction.

Sorry for not posting in over 2 years, I’m working to change that.

Upcoming posts:

  • Avaya Phone System
    • System and Session Mananger
    • Communication Manager
    • 46xx, 96xx series handsets
    • H.323 and SIP protocols
  • Exchange Unified Messaging (HA & DR) implementation and administration
  • Polycom Video Conferencing
    • RealPresence Desktop and Websuite
    • HDX7000
    • Group Series 500
  • Cisco Commands
    • Cisco 3850
    • Cisco ASA 5505x
  • Skype for Business (HA and DR) implementation and administration
  • Extron Audio Video Associate Certification
  • Data Center and IDF cable plant management
  • Retro Pie (Raspberry Pie)
  • CBTNuggets.com online training courses. I am 127 hours and 374 videos in – and i love it! Here are some of the courses I’ve attended:
    • IPv4 Subnetting
    • Microsoft Exchange Server 2013: 70-341
    • Penetration Testing with Linux Tools
    • Citrix NetScaler 10.5 1Y0-253
    • PowerShell 4 Fundamentals
    • Cisco CCENT/CCNA ICND1 100-105
    • Cisco Virtual Internet Routing Lab (VIRL) 1.x
    • Cisco CCNA Security 210-260 IINS
    • GNS3 1.x Fundamentals
    • CompTIA Security+ SY0-401
    • Exam Walkthrough: Cisco ICND2/CCNA 200-101
    • Wireshark
    • Cisco CCNA ICND2 200-101
    • Cisco CCNA ICND2 200-105
    • EC Council Certified Ethical Hacker v9.0
    • Microsoft SCCM 2012 70-412 with R2 Updates
    • Powershell Reference Training
    • Microsoft Windows Server 2012 70-410 with R2 Updates
    • Microsoft SharePoint 2016 Fundamentals
    • Microsoft PowerPoint 2016
    • Photoshop for Developers
    • Microsoft Visual Studio 2012 70-480
    • Java Essentials




Citrix NetScaler 10.5

I’m currently working on a project where load balancing is required.  I’ve never had the need to load balance in my personal labs so I wanted to educate myself on the matter.  I turned towards CBTNuggets.com because they offer a “Citrix NetScaler 10.5 1Y0-253 NetScaler 10.5 Essentials and Networking” course with Keith Barker.   Once again, I highly recommend you visit CBTNuggets.com, they provide great training videos for a number of technologies. Below are my notes from the course, they’re not complete (and images removed) because i don’t want to infridge on any copyrights.

The Citrix NetScaler 10.5 for App and Desktop Solutions course provides the concepts and training to install and configure a Citrix NetScaler load balancer and gateway in a virtualization environment such as Citrix XenDesktop/XenApp 7.x. Learners are strongly encouraged to build a lab environment to practice the NetScaler techniques learned in this course. This course is based on the Citrix NetScaler 10.5 product, and the fundamental concepts taught in these Nuggets are common to earlier NetScaler versions as well.

Citrix NetScaler is a multi-functional appliance that can perform as a Layer 4-7 proxy for load balancing, as well as an SSL VPN gateway (or both). Environments that include Citrix XenApp and XenDesktop are likely to use a NetScaler as their remote access and load balancing solution.

The Citrix NetScaler (NS) is a Physical (MPX, SDX) or Virtual (VPX) multi-functoinal appliance that can perform as an ISO Layer 4-7 proxy (Web Application Delivery Controller (ADC)  for load balancing, as well as a security gateway (SSL VPN, Posture Scans, Authentication), or both. NS is a TCP/IP Proxy. Packaged as an Open Virtual Format (.ovf) file.

Virtual IP address (VIP) – Address of the Virtual Server (VS), there will be multiple VS created on the NS.

Subnet IP (SNIP) – Is a configured address that the NS uses to communicate with other servers on that subnet.  SNIP purpose is for NS to believe it is directly connected to that specific network.

NSIP – NetScaler IP is the base address of the device.

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Avaya Phone System

I recently started reading about Avaya phone systems and I figured I would post some of the knowledge I’ve gained before I forget it; this way I will always have a reference. Below are some of the basic commands that you should be familiar with when working with Avaya phone systems. This is in no way a complete list of commands. For more information regarding Avaya Phone Systems and their configuration settings please visit Avaya at http://www.avaya.com

The following commands should be ran in Avaya Communication Manager.

Avaya Communications Manager organizes and routes voice, data, image, and video transmissions. As we all know back-ups are essential. Manual backup type: save transition. To check if your system is backing up automatically type: display system-parameters maintenance

Dial Plan

Your dial plan tells your system how to interpret dialed digits.

Acronyms

  • Attendant (attd)
  • Dial Access Codes (dac)
  • Trunk Access Codes (tac)
  • Extensions (Ext)
  • Feature Access Codes (fac)

To display your dial plan type: display dialplan analysis
To modify your dial plan type: change dialplan analysis

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Skype for Business 2015 Implementation

I am implementing Skype for Business 2015 in a high availability and redundant, design.  The below topology is what we’re shooting for.  To increase security on our Edge Servers we’ve decided to create two DMZ zones.  We’re also using Citrix NetScalers for load balancing and reverse proxy.  Wish me luck!




Cable Management project for IDF closets

I was recently left in charge with grooming multiple IDF closets and as you can see below these closets were neglected for years.  We decided to install NetPatch cable management which required re-punching and rearranging patch panels and switches, but after all the long hard word I am quite pleased with the outcome. I also revoked access for the people who managed these closets previously, now I am responsible for all the cross-connects.

Before and After

Before – During – After

 




Open Source Routing (DD-WRT) – Project -Networking

I use multiple routers and switches on both production and lab networks that I maintain.  With all the vulnerabilities in SOHO routers and their manufactures not updating firmware quick enough (or at all) I decided to research alternatives.

I found multiple open source communities which provide third-party firmware, which are designed to replace the original firmware on some commercial routers. The open source firmware that caught my eye is the DD-WRT.

This weekend I finally found time to install DD-WRT on my old Linksys WRT54G router.  I use this router from time to time on my Lab networks.

DD-WRT is a Linux based alternative Open Source firmware suitable for a great variety of WLAN routers and embedded systems.

 

References:

About DD-WRT

DD-WRT Wikipedia

Third-Party Firmware




HP Pavilion DV7 – Project – Repair

A client recently asked me to remediate all the issues he was having with his HP Pavilion dv7 laptop.  A quick diagnosis showed that it was riddled with malware and had a physical memory issue.  Instead of working through and removing the malware individually we decided it was best to format his hard drive and install his latest backup.  In addition to the format I replaced the RAM memory modules.

HP Pavilion dv7
Intel Core i7 2.3 GHz
8GB SDRAM RAM
1TB 5400rpm Hard Drive
17.3in diagonal HD+ BrightView
Windows 7 Home Premium 64-bit




Recently Read: Windows Server 2012 Unleashed

After installing a Windows 2012 Server on one of my lab networks I found myself reading Windows Server 2012 Unleashed by SAMS.  This is a very detailed book which is great for beginners or professionals.  It helped me experiment and configure various Server 2012 features such as DNS, AD, DHCP, and IIS.

Windows Server 2012 Unleashed

Valuable for Windows professionals at all skill levels, this book will be especially indispensable for intermediate-to-advanced level professionals seeking expert, in-depth solutions. Every chapter contains tips, tricks, best practices, and lessons learned from actual deployments: practical information for using Windows Server 2012 to solve real business problems.

  • Plan and migrate from Windows Server 2003 and 2008
  • Leverage powerful capabilities that are truly new in Windows Server 2012
  • Install Windows Server 2012 and the GUI-less Windows Server Core
  • Upgrade to Windows Server 2012 Active Directory
  • Utilize advanced AD capabilities including federated forests and identity management
  • Plan and deploy network services, from DNS and DHCP to IPv6, IPAM, and IIS
  • Protect systems and data with server-level security, transport-level security, and security policies
  • Deliver true end-to-end secured anytime/anywhere access to remote/mobile clients
  • Efficiently configure and manage users, sites, OUs, domains, and for­ests through Server Manager console
  • Create more fault-tolerant environ­ments with DFS, clustering, and Network Load Balancing
  • Leverage major Hyper-V virtualization improvements in availability, redun­dancy, and guest support
  • Manage Active Directory more efficiently with Active Directory Administrative Center, Best Practice Analyzer, and PowerShell scripts
  • Systematically tune, optimize, debug, and troubleshoot Windows Server 2012

References:

Windows Server 2012 Unleashed




Good To Know: WPAD Man-In-The-Middle

I recently found myself reading about an older man-in-the-middle attack:

WPAD Man In The Middle Attacks

Web Proxy Auto-Discovery Protocol (WPAD)

Used to intercept web traffic by using a non-authorized server as a proxy server. This can lead to various attacks as simple as capturing clear text passwords on an internal network.

References:

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-1999-0858

http://www.netresec.com/?page=Blog&month=2012-07&post=WPAD-Man-in-the-Middle

https://www.trustedsec.com/july-2013/wpad-man-in-the-middle-clear-text-passwords/




Cisco’s 8-Step Problem-Solving Model

Cisco General Problem-Solving Model

When troubleshooting a problem a systematic approach works best because the opposite can result in wasted time and resources, and can sometimes make symptoms even worse.

The following is Cisco’s 8 Step Problem-Solving Model:

Step 1:  When analyzing a network problem, make a clear problem statement. You should define the problem in terms of a set of symptoms and potential causes.
To properly analyze the problem, identify the general symptoms and then ascertain what kinds of problems (causes) could result in these symptoms. For example, hosts might not be responding to service requests from clients (a symptom). Possible causes might include a misconfigured host, bad interface cards, or missing router configuration commands.

Step 2:  Gather the facts that you need to help isolate possible causes.
Ask questions of affected users, network administrators, managers, and other key people. Collect information from sources such as network management systems, protocol analyzer traces, output from router diagnostic commands, or software release notes.

Step 3:  Consider possible problems based on the facts that you gathered. Using the facts, you can eliminate some of the potential problems from your list.
Depending on the data, for example, you might be able to eliminate hardware as a problem so that you can focus on software problems. At every opportunity, try to narrow the number of potential problems so that you can create an efficient plan of action.

Step 4:  Create an action plan based on the remaining potential problems. Begin with the most likely problem, and devise a plan in which only one variable is manipulated. Changing only one variable at a time enables you to reproduce a given solution to a specific problem. If you alter more than one variable simultaneously, you might solve the problem, but identifying the specific change that eliminated the symptom becomes far more difficult and will not help you solve the same problem if it occurs in the future.

Step 5:  Implement the action plan, performing each step carefully while testing to see whether the symptom disappears.

Step 6:  Whenever you change a variable, be sure to gather results. Generally, you should use the same method of gathering facts that you used in Step 2 (that is, working with the key people affected, in conjunction with utilizing your diagnostic tools).

Step 7:  Analyze the results to determine whether the problem has been resolved. If it has, then the process is complete.

Step 8:  If the problem has not been resolved, you must create an action plan based on the next most likely problem in your list. Return to Step 4, change one variable at a time, and repeat the process until the problem is solved.

 

References
http://www.cisco.com/en/US/docs/internetworking/troubleshooting/guide/tr1901.html#wp1020562




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