A common network security practice is to use different components to provide network separation. If you’re planning to take the SY0-501 or SY0-401 Security+ exam, you should have a basic understanding of implementing secure network architecture concepts. This includes physical security and logical security methods used for isolation.
As an example, see if you can answer this question?
Q. You are tasked with configuring a switch so that it separates VoIP and data traffic. Which of the following provides the BEST solution?
A. NAC
B. DMZ
C. SRTP
D. VLAN
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Network Separation
A common network security practice is to use different components to provide network separation. The CompTIA objectives list these as segregation, segmentation, and isolation. Segregation provides basic separation, segmentation refers to putting traffic on different segments, and isolation indicates the systems are completely separate. Chapter 1 of the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide covers virtualization concepts in depth and virtualization can be used to provide isolation. For example, some antivirus experts use virtual machines to analyze malware.
Logical Separation and Segmentation
Routers and firewalls provide a basic level of separation and segmentation. Routers segment traffic between networks using rules within ACLs. Administrators use subnetting to divide larger IP address ranges into smaller ranges. They then implement rules within ACLs to allow or block traffic. Firewalls separate network traffic using basic packet-filtering rules and can also use more sophisticated methods to block undesirable traffic.
It’s also possible to segment traffic between logical groups of users or computers with a virtual local area network (VLAN). This provides logical separation.
The 601 Version of the Study Guide
The CompTIA Security+: Get Certified Get Ahead: SY0-601 Study GuideEach of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.
Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
Comparing a Layer 2 Versus Layer 3 Switch
A traditional switch operates on Layer 2 of the Open Systems Interconnection (OSI) model. A traditional switch (a Layer 2 switch) uses the destination MAC address within packets to determine the destination port. Additionally, a Layer 2 switch forwards broadcast traffic to all ports on the switch.
Routers operate on Layer 3 of the OSI model. They forward traffic based on the destination IP address within a packet, and they block broadcast traffic. A Layer 3 switch mimics the behavior of a router and allows network administrators to create virtual local area networks (VLANs). Because a Layer 3 switch forwards traffic based on the destination IP address instead of the MAC address, it is not susceptible to ARP-based attacks.
Isolating Traffic with a VLAN
A virtual local area network (VLAN) uses a switch to group several different computers into a virtual network. You can group the computers together based on departments, job function, or any other administrative need. This provides security because you’re able to isolate the traffic between the computers in the VLAN.
Normally, a router would group different computers onto different subnets, based on physical locations. All the computers in a routed segment are typically located in the same physical location, such as on a specific floor or wing of a building.
However, a single Layer 3 switch can create multiple VLANs to separate the computers based on logical needs rather than physical location. Additionally, administrators can easily reconfigure the switch to add or subtract computers from any VLAN if the need arises.
For example, a group of users who normally work in separate departments may begin work on a project that requires them to be on the same subnet. You can configure a Layer 3 switch to logically group these workers together, even if the computers are physically located on different floors or different wings of the building. When the project is over, you can simply reconfigure the switch to return the network to its original configuration.
As another example, VoIP streaming traffic can consume quite a bit of bandwidth. One way to increase the availability and reliability of systems using this voice traffic is to put them on a dedicated VLAN. Other systems transferring traditional data traffic can be placed on a separate VLAN. This separates the voice and data traffic within the VLAN.
Similarly, you can use a single switch with multiple VLANs to separate user traffic. For example, if you want to separate the traffic between the HR department and the IT department, you can use a single switch with two VLANs. The VLANs logically separate all the computers between the two different departments, even if the computers are located close to each other.
Remember this
Virtual local area networks (VLANs) separate or segment traffic on physical networks and you can create multiple VLANs with a single Layer 3 switch. A VLAN can logically group several different computers together, or logically separate computers, without regard to their physical location. VLANs are also used to separate traffic types, such as voice traffic on VLAN and data traffic on a separate VLAN.
Q. You are tasked with configuring a switch so that it separates VoIP and data traffic. Which of the following provides the BEST solution?
A. NAC
B. DMZ
C. SRTP
D. VLAN
Answer is D. A virtual local area network (VLAN) provides separation for traffic and can be configured to separate Voice over IP (VoIP) traffic and data Network access control (NAC) solutions inspect clients for health after they connect to a network.
A demilitarized zone (DMZ) provides a layer of protection for Internet-facing systems, while also allowing clients to connect to them.
Secure Real-time Transport Protocol (SRTP) provides encryption and authentication for Real-time Transport Protocol (RTP) traffic.
RTP is used for audio/video streaming, such as in video teleconferencing applications.
See Chapter 3 of the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide
Or
Chapter 3 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide
for more information on implementing a secure network.
