50 CCNA Interview Questions and Answers

CCNA Interview Questions

1.What is the 2nd layer of OSI layer model?
Data link layer is the second layer of OSI model.

2.Which routing protocol through its routing table after each 30 seconds?
RIPv1

3.What is half duplex?
In half duplex, communication occurs only in one direction.

4.What is the main difference between full and half duplex?
In full duplex, communication occurs from both side, while in half duplex communication occurs in one direction.

5.At which layer HUB works?
HUB work at layer 1 of OSI model

6.What is the key main difference between Hub and switch?
Switch works at layer 2 of OSI while hub at layer 1. Switch is commonly used to make separate domain while Hub have no concept of separate domains.

7.What are 2 type
First we will ping the IP of 0/1 serial interface. If it is not reachable then we will use #show ip int brief command to check what the issue is. If the issue is not in hands then you can use #show interface serial 0/1 to see what exactly the issue is.

8.How can you explain a network subnet? What is it?
A network subnet is a subdivision of an IP network address

9.At which layer of OSI does frame relay technology work?
Frame relay work at Data link layer OSI model

10.Which protocol allows preventing loop free network in switching network?
The most usable protocol is Spanning Tree Protocol.

11.Can you assign IP on layer 2?
No, you cannot assign IP addresses on layer 2.

12.How can you telnet a switch which is a layer 2 device and you cannot assign IP on it.
To telnet a switch, there are many ways you can do this. The most common is to assign IP address to a Vlan 1 and make its IP reachable to all attached devices.

13.What is OSPF stand for?
Open shortest path first

14.How many types of passwords you can use in Cisco’s routers?
There are five types of passwords you can assign to any cisco router. These are enable, enable secret, auxiliary, console and virtual terminal.

15.What is a Vlan used for?
Virtual LANs are used to make separate domain in a single switch.

16.Why you need to make different Vlans for different departments in your company?
It is because it will give a security and performance capability to each department using attached devices.

17.What is the range of Class A?
1-126

18.How many host are in Class A?
There are total 127 million hosts are in Class A in 127 networks.

19.What is PoE?
PoE is said to be Power over Ethernet. It is used pass electric signal with data at a time.

20.224.0.0.10, to which class this IP belongs to?
This is a multicast address. It is a Class D address.

21.Can you use two different subnet IP’s on a WAN link?
Yes.

22.Which Vlan is used for native data purpose of switch 3560?
By default, Vlan 1 is used for native vlan in 3560 switch.

23.Which port telnet used to connect with a remote device?
Port 25

24.How many ports are reserved for special purposes which host services like HTTP, FTP, and POP3 etc.
Ports from 1 to 1024 are reserved for special services and will only be used by system administrator.

25.The traditional STP takes 40 to up the port, what will you to make it up immediately?
Use this command on global configuration mode #spanning tree mode r-pvst. This command will make ports up immediately.

26.What does ARP do in a network?
The purpose of ARP is to trace IP addresses to MAC address.

27.What is the range of the Class C?
192-223

28.How many hosts can be in Class C total?
Class C can support 254 hosts per network and total network can be used is about 2 million.

29.What does PING stands for?
Ping stands for Packet Internet Groper

30.What is the size of a cisco ping packet?
The size of a Ping packet in cisco by default is 100 bytes

31.How can you transfer different vlans in a single physical wire?
You can make trunk of two switches and can send allowed vlans from it concurrently.

32.What is the default configuration revision number of cisco switch 2950?
The default revision number is 0

33.How can you say your router is accessible?
You simply need to PING that router. If the reply comes from the router then it is accessible.

34.How RIP work in a switch?
You cannot use RIP in a switch on layer 2

35.What does MTU stands for?
MTU stand for maximum transmission unit. If you have configured a router the default MTU is set. The default MTU size is 1500 bytes.

36.What is a packet of data?
It contain source information, destination information, protocol version using. It also contain numeric identification number.

37.How many VTP modes are in a switch and what are they?
There are three type of VTP mode, these are Server, client and transparent.

38.In which type EIGRP routed protocol falls?
EIGRP is not routed protocol it is a routing protocol and falls in hybrid type.

39.Which port does RIP use of TCP?
RIP use port of UDP (not TCP) 520.

40.In which version of RIP there is an optional field which can be used for authentication purpose?
RIPv2

41.Which feature should a routing protocol have to support VLSM?
It should include subnet mask of each destination address.

42.What is intermediate system used for?
It is basically an ISO term used by router

43.What does AAA stands for?
Authentication, authorization and accounting

44.What does HSRP protocol do?
It provides a high availability of redundant nodes. With HSRP, if one link goes down, another link comes up with in milli-seconds.

45.What is the maximum value of administrative you can use?
255

46.Give me a definition of network in few words.
Connectivity of two or more devices so that they can communicate with each other

47.Is HSRP is cisco proprietary or introduced by IEEE?
HSRP is Cisco’s proprietary

48.If you using a redundant link between switch. If one link goes down, how much time it will take for the second link to get up.
It will take about 40 seconds for normal STP.

49.At which layer IPX work?
IPX work at layer 3 of OSI model which is network layer.

Read more

More Resume

Interview Questions with Answers

Study Material