Basic Networking Interview Questions and Answers
Question: What is a VLAN? What does VLAN provide?
Ans: VLAN is termed as Virtual Local Area Network. It is a logical grouping or segmentation of a network connected to administratively defined ports on a switch, they provide Broadcast control, Flexibility and Security.
Question: What is Subnetting? Why is it used?
Ans: Subnetting is used in IP Networks to break up larger networks into smaller sub-networks. It is a way to divide network in the best possible way so the IP Address do not get wasted. It also allows the flow of network traffic between hosts to be segregate based on network configuration. By organizing hosts into logical groups, subnetting can improve network security & performance.
Question: What is difference between Switch & Hub?
Ans: Switches operate at Layer 2 Data Link Layer, it learns address, forward or filter decision using MAC address, breakup collision domains and and also helps in loop avoidance whereas Hub operates at Layer 1 Physical Layer, it does not do filtering
or addressing. Hub also creates single collision domain and single broadcast domain.
Question: What is the ICMP protocol?
Ans: ICMP is termed as Internet Control Message Protocol which is a Network Layer Internet protocol can report errors and status information. We can use the ping command to send ICMP echo request messages and record the receipt of ICMP echo reply messages. With these messages, we can detect network or host communication failures and troubleshoot common TCP/IP connectivity problems.
Question: What is OSI Model? What are the 7 layers of OSI Model.
Ans: OSI is termed as Open System Interconnection which is a referencing model on how communication happens over a network. It has 7 Layer as follows:
Physical (Layer 1)
Data Link (Layer 2)
Network (Layer 3)
Transport (Layer 4)
Session (Layer 5)
Presentation (Layer 6)
Application (Layer 7)
Question: What is segmentation and fragmentation?
Ans: To divide data in pieces is called segmentation and divide segmentation in pieces called Fragmentation. IP fragmentation occurs at Layer 3 (IP) and that TCP segmentation occurs at Layer 4 (TCP).
Question: What is FCS?
Ans: FCS is also termed as Frame Check Sequence. When CRC or Cyclic Redundancy Check algorithm runs in switch is called as FCS.