Technology

5.4.14 Hop count exceeded – possible mail loop ATTR34

Issue: We recently configured our Exchange Hybrid setup and were experiencing this error when sending mail from our mailboxes migrated to Exchange Online to the mailboxes still on Premise that had the alias: @ourdomain.mail.onmicrosoft.com (On Premise Mailboxes had this alias setup in preparation for migrating to Exchange Online). Cause: We use Mimecast for our email filtering. The mail loop was…

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PowerShell, Technology

Powershell: Automating Exiting Users

Introduction I have being playing around with Powershell a lot more lately and trying to learn and utilise it as much as possible. One of the repetitive tasks we deal with is when a student exits the school. There are a number of steps in AD that have to be undertaken each time a student leaves. These include: Disable the…

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PowerShell, Technology, Uncategorized

PowerShell Resources

As a Sys Admin, I am probably a bit late to the party with how useful PowerShell can be. I have lately completed a couple of online courses about PowerShell and am trying to use it as much as I can in my day to day work. I am finding it incredibly useful in work and relatively easy to pick…

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SQL Server, Technology

SQL Server Database Backups

Backups are crucial. You need to have the right backups in place to have your data covered in the case of any disasters. In this post I go through the different backup types and some of the different strategies for implementing them.

Comptia Security+, Security, Technology

Security+ Course – 6.6 Cryptanalytic attacks

1. Brute Force Attacks Brute-force attacks are the simplest form of attack against a cryptographic system. In a brute-force attack, the attacker simply guesses repeatedly at the encryption key until he or she stumbles upon the correct value for the key and gains access to the encrypted information. Brute-force attacks can take a very long time to complete successfully, if…

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Comptia Security+, Security, Technology

Security+ Course – 6.5 Public Key Infrastructure (PKI)

1. Trust Models Requirements for Symmetric Key Exchange: The 2 parties must be confident that they are really communicating with each other and not an imposter The 2 parties must be confident that nobody is eavesdropping on the key exchange Asymmetric Cryptography Users don’t need to share their private keys Users can share their public keys freely Eavesdropping protection isn’t…

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Comptia Security+, Security, Technology

Security+ Course – 6.4 Key Management

1. Key Exchange In symmetric encryption, the sender and receiver share a single secret key that nobody else should know. Before the sender and receiver can begin to communicate using a symmetric algorithm, they must somehow agree upon and exchange the shared secret key that they will use for that communication session. Problems with Key exchange EG: Alice and Bob…

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Comptia Security+, Security, Technology

Security+ Course – 6.3 Asymmetric Cryptography

1. Rivest-Shamir-Adleman (RSA) Asymmetric cryptography solves issues of scalability by giving each user a pair of keys for use in encryption and decryption operations. The RSA algorithm was one of the earliest asymmetric cryptographic algorithms and it is still used today. It was published in 1977. There’s a lot of complex maths involved in creating that key pair, but the…

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Comptia Security+, Security, Technology

Security+ Course – 6.2 Symmetric Cryptography

1. Data Encryption Standard (DES) DES was designed by IBM in the 1970’s Intended to serve as a federal encryption standard. Up until that point different agencies used different encryption algorithms. This caused issues with security because all of those algorithms weren’t thoroughly tested, and interoperability because different agencies couldn’t easily communicate with each other How DES Works DES uses…

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