CCNA Interview Questions

CCNA Interview Questions | Freshers & Experienced

  • Satyam Jaiswal
  • 03rd Jan, 2020

CCNA Interview Questions and Answers

Q1. What is CCNA and CCNP in networking?

CCNA (Cisco Certified Network Associate ) is a certification course by Cisco. The core CCNA certification is CCNA (Routing & Switching), however, Cisco offers other Specializations which including CCNA Wireless, CCNA Collaboration, and CCNA Security.

CCNA certification will not only prepare you with the knowledge of foundational technologies but ensure you stay relevant with the skills & techniques required for the adoption of next-generation technologies.

While CCNP(Cisco Certified Network Professional) is an individual who acquires the Cisco Career Certificate.If we talk about the validity of CCNP Certification is 3 years only.

There are presently about seven pathways of the professional certification in Cisco Career certifications.

  • CCDP
  • CCNP Cloud
  • CCNP Collaboration
  • CCNP Data Center
  • CCNP Routing and Switching
  • CCNP Security
  • CCNP Service Provider
  • CCNP Wireless

Q2. What is a Frame Relay?

Frame relay is a transmission mode that is used to connect local area network (LANs) or transport data between endpoints in Wide Area Network (WANs).

Frame relay puts data in a variable-size unit called a frame and leaves any necessary error correction (retransmission of data) up to the endpoints, which speeds up overall data transmission.

The Frame Relay network handles the transmission over a frequently changing path transparent to all end-user extensively used WAN protocols. It is less expensive than leased lines and that is one reason for its popularity

Q3. What can you do with a CCNA?

You can easily find a good job, Cisco offers 10 CCNA certifications that each validate different skill sets:

  • CCNA Routing and Switching
  • CCDA
  • CCNA Cloud
  • CCNA Collaboration
  • CCNA Cyber Ops
  • CCNA Data Center
  • CCNA Industrial
  • CCNA Security
  • CCNA Service Provider
  • CCNA Wireless

Q4. What is the difference between 'bit rate' and 'baud rate'?

Bit rate and baud rate are not always the same.

Bit rate defines the number of bits transmitted per second(b).

Baud rate defines the number of symbols transmitted per second (s).

Now let's clear with the help of an example:-

Ex1:- What is the bit rate and baud rate for an analog signal that carries 4 bits in each signal unit if 1000 signal units are sent per second?

Baud rate = 1000 baud per second
Bit rate = 1000 x 4 = 4000 bps.

Ex2:- What is the baud rate for an analog signal if the bit rate of the signal is 5000 and each signal unit carries 10 bits?

Baud rate = 5000 / 10 = 500 baud

Q5. Define Bandwidth.

Bandwidth referred to the volume of information per unit of time that a transmission medium (like an Internet connection) can handle. Bandwidth is also defined as the amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second(bps) or bytes per second. for the analog signal, it is given in Hz and in the digital signal, it is given in bits per second.

Bandwidth is of two types:-

  • High Bandwidth:- It has a high-speed connection & it leads to an enormous internet bill of you are unaware of what content on the internet consumes more data.
  • Low Bandwidth:- It ends up providing lower network speed/data transmission speed & a connection with low bandwidth will be more pocket-friendly for starters.

Q6. What is Domain Name System (DNS)

Domain Name System (DNS) is the phonebook of internet. Any individual can access information online through domain names, like, It is an application layer protocol for message exchange between clients and servers.

The Domain Name System delegates the responsibility of assigning domain names and mapping those names to Internet resources by designating authoritative name servers for each domain.

There are various kinds of DOMAIN are:-

  • Country domain .in(India) .
  • general domain:- .com(commercial) .edu(educational) .mil(military) .org(non profit organization) .net(similar to commercial).

Q7. What is latency?

Latency is also called delay. It is the amount of delay (or time) it takes to send information from one point to the next. Latency is usually measured in milliseconds or ms. It’s also referred to (during speed tests) as a ping rate.

There are some typical values, approximate values for latency:-

  • 800ms for satellite
  • 120ms for 3G cellular data
  • 60ms for 4G cellular data which is often used for 4G WAN and internet connections
  • 20ms for an Mpls network such as BT IP Connect, when using Class of Service to prioritize traffic
  • 10ms for a modern Carrier Ethernet network such as BT Ethernet Connect or BT Wholesale Ethernet in the UK

Q8. What is OSPF? Describe it.

Open Shortest Path First (OSPF) is for finding the best path between the source and destination router using its own shortest path first.

If we talk about the RIP(Routing Information Protocol) is now replaced by the OSPF routing protocol in the corporate network.

OSPF terms are:-

  • Router I’d
  • Router priority
  • Designated Router (DR)
  • Backup Designated Router (BDR)

OSPF has the following states:-

  • Down
  • INIT
  • 2WAY
  • Exstart
  • Exchange
  • Loading
  • Full

Q9. What is EIGRP?

EIGRP (Enhanced Interior Gateway Routing Protocol) is an interior gateway protocol that is accepted for many different topologies and media. Using EIGRP, a router keeps a copy of its neighbor's routing tables.

EIGRP uses some messages to communicate with the neighbor devices that operate EIGRP.

These are some:-

  • Hello message
  • NULL update
  • Full Update
  • Partial update
  • Query message
  • Reply message
  • Acknowledgment message

Q10. In how many ways you can access the router

There are several methods to access Router :-

  • Physically Console Access 
  • Remotely Telnet ( Mostly use within the LAN Network)
  • Web base SSH ( Remotely web base access)
  • Through VPN (The most secure method of them) by using cisco VPN client and any3rd party VPN client software.
  • Using the lanewire and router ip address
  • directly access via the wifi signals.

Q11. Explain the difference between Tracert and Traceroute.

Some difference between Tracert and Traceroute:-

Traceroute is a command which can show you the path a packet of information takes from your computer to one you specify. It will list all the routers it passes through until it reaches its destination, or fails to and is discarded.

The tracert command is a command prompt command that's used to show several details about the path that a packet takes from the computer or device you're on to whatever destination you specify. Both working are the same but. But it depends on the platform that you choosed.

Q12. What is the size of IP address?

IP addresses are usually written and displayed in human-readable notations, size of an IP address is 32 bit or 4 Byte.

IP address contains 4 octet where each octet separated by .(dot). , such as,,

Same IP address in bonary form will be 00001010.00000001.00000010.00000011

There are two version of IP address :-

  • IP version 4 :- IPv4 address consists of 4 octets 8 bit each.This makes there size as 32 bit. It is written in Decimal.
  • IP version 6 :- IPv6 address consists of 8 hexadecimal sets which makes this as 128 bit long.It is usually mentioned in hexadecimal itself to make it easier.

Q13. What is the difference between the switch, hub, and router

When we compare switch, hub, & router these all are similar but there are some differences between the way in which they handle the data.

So let's talk about one by one.


The purpose of the hub is to connect all of your network devices together on an internal network. It is a device that has multiple ports that accept Ethernet connections from network devices. Now a hub is considered not to be intelligent. Because it does not filter any more data or has any intelligence as to where the data is supposed to be sent that is because the only thing hub knows is when a device is connected to one of its ports.


It is very similar to the hub. It is also a device that has multiple ports that accepts Ethernet connections from network devices. But unlike a hub, a switch is intelligent.

Router : -

A router does exactly what its name implies. A router is a device that routes data from one network to another based on their IP address. When a data packet is received from a router the router inspects the data's IP address and determines if the packet was meant for his own network or if it is meant for another network. If the router determines the data packet is meant for its own network then it receives it.

Q14. What are the 7 Layers of the OSI Model?

OSI Model (Open System Interconnection) model was established in 1947 by the ISO(International Standards Organization).

It is used to defines a computer networking.

Framework for the implementation of protocols in seven layers.

These layers are given below:-

  • Physical Layer:- Bluetooth, PON, OTN, DSL, IEEE.802.11, IEEE.802.3, L431 & TIA 449
  • Data Link Layer:- ARP, CSLIP, HDLC, IEEE.802.3, PPP, X-25, SLIP, ATM, SDLS & PLIP
  • Network Layer:- Internet Protocol(IPv4), Internet Protocol(IPv6), IPX, AppleTalk, ICMP, IPSec, & IGMP
  • Transport Layer:- TCP, UDP, SPX, DCCP, & SCTP
  • Session Layer:- PPTP, SAP, L2TP, & NetBIOS
  • Presentation Layer:- XDR, TLS, SSL, & MIME
  • Application Layer:- HTTP, HTTPS, SMTP, DNS, IMAP, LDAP, NTP, RTP, SNMP & SMPP.

Q15. What is the difference between CSMA/CD and CSMA/CA?

CSMA refers to Carrier Sense Multiple Access.


CSMA/CD(Carrier Sense Multiple Access/Collision Detection) is used wired networks & effects before collision. It is used for retransmit data frames when ever a collision occurred, & helps in reducing the possibility of collision.


CSMA/CA( Carrier Sense Multiple Access with Collision Avoidance) is wireless network, it effects before collision. CSMA/CA will first broadcast intent to send prior to data transmission & it has only minimizes the recovery time.

Q16. What is a Hub and what does it look like on the CCNA exam?

Hub purpose of the connect to all of your network devices together on an internal network. It is a device that has multiple ports that accept Ethernet connections from network devices.

Now a hub is considered not to be intelligent. Because it does not filter any more data or has any intelligence as to where the data is supposed to be sent that is because the only thing hub knows is when a device is connected to one of its ports

Q17. How to Configure a Management VLAN Interface

The router must have a physical or logical connection to each VLAN so that it can forward packets between VLANs.

Network communication is in some sort of two-way communication. So basically you should configure the VLANs on both sides (I speak about 802.1q). The border devices of your VLAN segment have to support it and be properly configured. It can be a switch or a computer. Even though I always made sure that all the devices on the VLAN network (up to the access port) supported it.

Q18. What is the purpose of the Data Link?

Data-link layer checks for physical transmission errors and packages bits into frames. It is responsible for transporting the data within a network.

The Data-Link layer consists of two sublayers:-

  • Logical Link Control (LLC) sublayer:-

    This is the upper sublayer. It is mainly responsible for framing, flow control, error detection, and error correction.

  • Media Access Control (MAC) sublayer:-

    This is the lower sublayer. It deals with how to share the link.

Data-link layer also provides the following services:-

  • Framing:
  • Error Correction and Detection
  • Multiple Access Control
  • Reliable Delivery

Q19. What is Peer to Peer network?

In Peer to Peer networking, two or more computers are linked together with equal permissions and responsibilities for processing data.

In a way, peer-to-peer networks are the most egalitarian networks in the computer world. Each peer is equal to the others, and each peer has the same rights and duties as the others. Peers are both clients and servers at the same time. The precursor of peer-to-peer networks appears to be USENET, which was developed in 1979.

Most common examples of peer to peer network:-

Torrent, A computer attached to LAN

Q20. What is BootP?

The Bootstrap Protocol implements is an applicant facility to load with a natural IP quantity and aspiration its IP address, an entrance address, and the address of a name server from a BOOTP server.

BOOTP (Bootstrap Protocol) is the successor of RARP (Reverse ARP) and the predecessor of DHCP. It does not provide a temporary IP address.

BOOTP does not support mobile machines & it is face down to errors due to manual configuration.

Q21. What is the max cable length before running into attenuation issues?

The max cable length before running into attenuation issues is 50 feet (15 m) because not surprisingly, it depends on the quality of the materials.

Attenuation is a very general term; it occurs at any length. At very short distances, reflection can occur, so is difficult to get a truly perfect signal.

If you are planning to have had longer than 100ft HDMI cable, then I highly suggest you use the cable extender, you will able to extend your HDMI up to 328ft, this is perhaps the longest distance of HDMI signal that you can transfer, by having multiple extenders.

Q22. What is the difference between static and dynamic IP addresses?

The difference between Static and Dynamic IP addresses lies within the duration of the assigned IP address.

Static IP address:- An address that is manually assigned to a particular machine by the administrator or it can even be an IP that is allocated by a DHCP server but does not change every time.

Dynamic IP address:- Dynamic IP address comes with a lease time that is set on the DHCP server by the network administrator. This IP changes after the lease time expire or the system reboots or renews its IP. This comes with others requires information of Gateway IP address and DNS IP address.

Q23. Differentiate full-duplex from half-duplex.

Half-Duplex is only one-sided communication. Only one can communicate at a time.

For example:- A walkie-talkie is a half-duplex device because only one party can talk at a time.

One can either send or receive information at a time

Full Duplex is the 2 direction communication. Both ends can communicate at the same time.

For example:- a telephone is a full-duplex device because both parties can talk simultaneously. Both tasks sending and receiving of information can be done simultaneously

Q24. What is MTU?

MTU stands for "Maximum Transmission Unit." The MTU is typically limited by the type of connection, but may sometimes be adjusted in a computer's network settings. Every network has a different MTU, which is set by the network administrator.

The internet's transmission control protocol (TCP) uses the MTU to determine the maximum size of each packet in any transmission. MTU of an Ethernet connection is 1500 is the maximum transmission unit of one packet.

Q25. Explain what is route poisoning?

Route poisoning means removing the particular routes from routers when that specific route is down or it's not reachable. When a router detects that one of its directly connected routes has failed, it will advertise a failed route with an infinite metric (“poisoning the route”).

The routing protocol simply informs all the routers connected in the network that a certain path is invalid by saying that it has a hop count that exceeds the maximum allowable.

About Author :

  • Author of CCNA Interview Questions

    Satyam Jaiswal

    Satyam is digital marketing expert, blogger from Allahabad Area. He loves to write technical articles and programming blog. He works on Onpage Seo, Social Media Groups and Off page Profile building

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