IT Exam Answers

cuivre sous forme d’impulsions électriques. Les impulsions électriques sont également susceptibles de générer des interférences de deux sources :
Interférences électromagnétiques (EMI) ou interférences radioélectriques (RFI) : les signaux électromagnétiques et radioélectriques peuvent déformer et détériorer les signaux de données transportés par les supports en cuivre.
Diaphonie : la diaphonie est une perturbation causée par les champs électriques ou magnétiques d’un signal d’un fil qui interfèrent avec le signal du fil voisin.

Le câblage réseau comprend différents types de câbles:
Le câblage UTP se compose de quatre paires de fils de cuivre un code couleur qui ont été torsadés, puis placés dans une gaine plastique souple.
Le câble STP utilise quatre paires de fils, chacun enveloppé dans un blindage en feuille, qui sont ensuite enveloppés dans une tresse ou feuille métallique globale.
Le câble coaxial utilise un conducteur en cuivre et une couche d’isolation en plastique flexible entoure le conducteur en cuivre.
Le câble de fibre est un brin de verre flexible, extrêmement mince et transparent entouré d’une isolation plastique.

La diaphonie est un type de bruit, ou d’interférence qui se produit lorsque la transmission du signal sur un fil interfère avec un autre fil. Lorsque le courant circule à travers un fil, un champ magnétique est produit. Le champ magnétique produit interfacera le signal transporté dans le fil adjacent.

The steps in the Vulnerability Management Life Cycle include these:

• Discover – inventory all assets across the network and identify host details, including operating systems and open services, to identify vulnerabilities
• Prioritize assets – categorize assets into groups or business units, and assign a business value to asset groups based on their criticality to business operations
• Assess – determine a baseline risk profile to eliminate risks based on asset criticality, vulnerability threats, and asset classification
• Report – measure the level of business risk associated with assets according to security policies. Document a security plan, monitor suspicious activity, and describe known vulnerabilities.
• Remediate – prioritize according to business risk and fix vulnerabilities in order of risk
• Verify – verify that threats have been eliminated through follow-up audits

1. Beats: Beats are lightweight, single-purpose data shippers. They are used to send data from hundreds or thousands of machines and systems to Logstash or Elasticsearch. Each Beat is tailored to ship specific types of data, like logs, metrics, or network packet data.
2. Elasticsearch: This is a distributed search and analytics engine. It is the core component that stores all the data you send to the Elastic Stack. Elasticsearch allows you to search, analyze, and visualize the data in real time.
3. Kibana: Kibana is a web interface for searching and visualizing logs and time-stamped data. It provides graphical representation of the Elasticsearch data and is used to create dashboards that enable users to interact with their data.
4. Logstash: This is the correct answer for the question. Logstash is a server-side data processing pipeline that ingests data from multiple sources simultaneously, transforms it, and then sends it to Elasticsearch. Logstash is equipped with an extensive plugin ecosystem that transforms and prepares your data regardless of the source or format – this includes making disparate data from various sources consistent and queryable.

In summary, Logstash is responsible for centralizing, transforming, and preparing data before it is indexed into Elasticsearch. It can dynamically unify data from disparate sources and normalize the data, making it ready for further analysis and visualization in Kibana.

A disadvantage of Dynamic DNS (DDNS) is:

Using free DDNS services, threat actors can quickly and easily generate subdomains and change DNS records.

This can be exploited for malicious purposes, such as creating command and control channels for malware or setting up phishing sites. Since the DNS records can be updated dynamically, it becomes difficult for law enforcement and security professionals to track and mitigate the threat. Additionally, because many DDNS services are legitimate and widely used, blocking them outright can have negative impacts on legitimate users.

A digital certificate must be revoked if it is invalid. CAs maintain a certificate revocation list (CRL), a list of revoked certificate serial numbers that have been invalidated. The user browser will query the CRL to verify the validity of a certificate.