Top 180 Networking Interview Questions for Beginners
Ultimate List Networking Interview Questions for Beginners & Freshers
Question 1:- What are the different network stack models and list all the layers of OSI model?
Question 2:- What are the functions of Trasport, Network, and Datalink layers?
Question 3:- What are the different protocols work at each of the layers?
Question 4:- What is end to end communication and Hop to Hop communication?
Question 5:- What is a port number and give some examples.
Question 6:- Explain IP layer ( L3) and IP protocol header.
Question 7:- What is fragmentation and explain how IP will handle the fragmentation.
Question 8:- What is the difference between Half-duplex and Full-duplex?
Question 9:- Define Unicast, Multicast and Broadcast. What is the use of Multicast?
Question 10:-What are the functions of Data link layer, what is the MAC format?
Question 11:- What is a Frame, explain the frame header.
Question 12:- A scenario to explain the packet flow layer wise.
Question 13:- What is IP address and it’s format.
Question 14:- What are the different Classes of IP address and give the range of each class.
Question 15:- What is network id , broadcast id and subnet mask?
Question 16:- How to find the netsork id of a given IP address?
Question 17:- What is subnetting and give us a scenario for implementing IP subnetting, a task on subnetting.
Question 18:- What is the difference between FLSM and VLSM?
Question 19:- What is the subnetwork address if the destination address is 18.104.22.168 and the subnet mask is 255.255.240.0?
Question 20:- What is the subnetwork address if the destination address is 22.214.171.124 and the mask is 255.255.192.0?
Question 21:- A company is granted the site address 126.96.36.199 (class C).
Question 22:- The company needs six subnets. Design the subnets.
Question 23:- A company is granted the site address 188.8.131.52 (class B). The company needs 1000 subnets. Design the subnets
Question 24:- You want to implement class c IP addresses in your network.so, what subnet mask you should implement in your network so that number of subnets will be equal to the number of hosts per subnet
Question 25:-ARP works at which layer and Why?
Question 26:- Is ARP part of the Ethernet frame?
Question 27:- What is the target IP address in ARP request and ARP reply packet?
Question 28:- What is GARP and how it will be useful?
Question 29:- Difference between ARP and GARP?
Question 30:-What is the target IP address in GARP request and GARP reply packet?
Question 31:- Packet structure of ARP and GARP?
Question 32:- Explain various ICMP messages?
Question 33:- Which ICMP message confirms the traceroute is completed?
Question 34:- Which is the importance of identification field in the IP packet?
Question 35:- Why fragmentation is required?
Question 36:- Which device can reassemble the packet?
Question 37:- How the packet is reassembled?
Question 38:- What is the importance of DF, MF flag?
Question 39:- What is the purpose of fragment offset?
Question 40:- What is the importance of TTL value?
Question 41:- What does the protocol field determines in the IP packet?
Question 42:- Explain 3 way handshake process?
Question 43:- What is the importance of sequence number?
Question 44:- How sequence number is calculated?
Question 45:- What is the purpose of acknowledgement number?
Question 46:- What is the difference between Total length and header length?
Question 47:- What does window size indicate?
Question 48:- When the MSS value is getting negotiated?
Question 49:- Explain the control flag?
Question 50:- What is the difference between PUSH and URG flag?
Question 51:- What is the purpose of RST bit?
Question 52:- What is SACK?
Question 53:- Who is responsible for the reliability of UDP packet.
Question 54:- Difference between TCP and UDP.
Question 55:- In a serialized connected network including Router, Switches and Firewall with varied MTU sizes Which device will fragment the packet and what are the sizes of each fragment?
Question 56:- Why Firewall reassembles the packet?
Question 57:- What Firewall verifies after reassembling the packet?
Question 58:- Can reassembly done by intermediate device?
Question 59:- Is fragmentation applicable only for TCP?
Question 60:- Can we fragment packet containing UDP data?
Question 61:- What is the difference between Active and Passive FTP?
Question 62:-What is the important of port command?
Question 63:- Which FTP type is preferred if firewall is blocking the connection?
Question 64:- How active FTP works?
Question 65:- How passive FTP works?
Question 66:- How TFTP works? Explain the protocols involved.
Question 67:- What is SNMP?
Question 68:- SNMP versions.
Question 69:- Components of SNMP?
Question 70:- Ports used in SNMP?
Question 71:- Explain MIB?
Question 72:- Explain how to implement SNMP on a network?
Question 73:- Explain difference between SNMP Query response & SNMP trap?
Question 74:-What are the various instances of getting “Request timed out”?
Question 75:- Difference between destination host unreachable and destination network unreachable?
Question 76:- Explain various ICMP messages?
Question 77:- How traceroute works?
Question 78:- What is the difference between traceroute and tracert?
Question 79:- Is traceroute a reliable tool to identify network issues?
Question 80:- Why there are three columns in traceroute results?
Question 81:-Which ICMP message confirms the traceroute is completed?
Question 82:-What does * indicate in traceroute result?
Question 83:- Difference between HTTP & HTTP/S?
Question 84:-How DHCP works?
Question 85:-What is the reason for getting APIPA address?
Question 86:- How to troubleshoot APIPA issue?
Question 87:- What is the purpose of relay agent?
Question 88:- Is DHCP decline message is sent by Client or Server?
Question 89:- Is DHCPNACK message is sent by Client or server?
Question 90:- How DHCP discover message is being forwarded by router when it is a broadcast message?
Question 91:- Explain zone transfer?
Question 92:- What are the types of records?
Question 93:- What is forward lookup & Reverse lookup?
Question 94:- When will DNS use TCP?
Question 95:- When will DNS use UDP?
Question 96:- Explain DNS quesr process.
Question 97:- Explain Auto negotiation.
Question 98:- What is MDI & MDIX ports?
Question 99:- Explain Straight Through & Cross Over cabling. Where will it be used.
Question 100:- What is inter vlan routing?
Question 101:- What is sub interface?
Question 102:- What is a broadcast domain and a collision domain
Question 103:- Compare HUB and Switch WRT broadcast and collision domain
Question 104:- What is a MAC address table and how a Switch will build a MAC table, single switch scenario and multiple switch scenario
Question 105:- What is a VLAN and how it will reduce the broadcast traffic
Question 106:- What is the difference between an access port and a trunk port and what are different types of tagging
Question 107:- What is a native VLAN what type of traffic will go through native VLAN
Question 108:- What is STP and why do we need redundant links between switches,
Question 109:- What are the different port states and timers and BPDU
Question 110:- What is bridge id and its format and the Root bridge election criteria
Question 111:- STP convergency with 4 switches, what is the Root port election criteria
Question 112:- What is TCN and TC BPDU and STP reconvergency
Question 113:- Can you explain the ARP Header with the fields?
Question 114:- What are the changes a frame undergoes in a switch
Question 115:- What is a routing table?
Question 116:- Define static routing & dynamic routing?
Question 117:- What is a default route?
Question 118:- What is a route metric?
Question 119:- What is the difference between routing and routed protocol? Give examples.
Question 120:- What is route lookup process, parent and child route
Question 121:- What is the effect of IP classless and classfull on routing
Question 122:- What are the different type of routing table entries and Admin distance
Question 123:- What are the different types of routing protocols and list for each type
Question 124:- What do you understand by backbone area?
Question 125:- What is the need for dividing the autonomous system into various areas?
Question 126:-What is the benefit of dividing the entire network into areas?
Question 127:- What changes it would make if the network is divided or not divided into areas?
Question 128:- What is the purpose of Stub area?
Question 129:- What is the purpose of NSSA area?
Question 130:- How Stub and NSSA works?
Question 131:- What are the criteria to form neighbour ship?
Question 132:- Why master slave needs to be elected between two neighbour interface?
Question 133:- What is virtual link?
Question 134:- Virtual link updates are multicast or unicast?
Question 135:- Explain the various states of OSPF?
Question 136:- What are various LSA and message Types?
Question 137:- What is the difference between E1 an E2 metrics?
Question 138:- Explain router redistribution?
Question 139:- How DR and BDR is elected?
Question 140:- Difference between eBGP and iBGP?
Question 141:- What is the TCP port number for BGP communication?
Question 142:- Explain various states of BGP?
Question 143:- What is the reason for an interface stuck on active state?
Question 144:- Do we need to follow 3 way handshake process to establish BGP communication?
Question 145:- What are various path attributes?
Question 146:- What is difference between Local preference and MED attributes?
Question 147:- Explain the sequence of selecting the best route through the attributes?
Question 148:- There are two PC connected to a switch, assign Ip address and explain how they will communicate for the first time.
Question 149:- Functionality of switch
Question 150:- what is MAC address? physical or logical address?
Question 151:- Difference between broadcast domain and collision domain?
Question 152:- What is Vlan?
Question 153:- what is dot1q?
Question 154:- what is STP, RSTP
Question 155:- Explain L2 loop?
Question 156:- What is ARP, Proxy ARP
Question 157:- Does ARP exceeds its broadcast domain
Question 158:- Explain DORA process with example both i.e server on same network and different network (DHCP imp topic should now in detail that is wireshark details)
Question 159:- Gracious ARP
Question 160:- Ipsec, GRE
Question 161:- what is native vlan
Question 162:- Have you ever connected end user via trunk port to a switch? if yes what is the outcome?
Question 163:- For routing atleast OSPF required, states and LSA
Question 164:-what is the roll of preamble in ethernet header?
Question 165:-Questions 165 What is Etherchannel
Question 166:-Describe Backgroud process of ICMP
Question 167:-what are the different layer of OSI model?
Question 168:- Functionality of different layers?
Question 169:- Difference between TCP and UDP
Question 170:- Different tcp and udp port used for communication name few with port no.
Question 171:- what is PDU?
Question 172:-Difference between icmp and Traceroute?
Question 173:-Expain three way handshake process?
Question 174:-What are TCP flags
Question 175:- What is fastswitching?
Question 176:- what is DNS?
Question 177:- How switch know the MAC address and how it makes its table?
Question 178:-what is root bridge?
Question 179:- conditions to select a root bridge?
Question 180:- What is bpdu guard, root gaurd?