Networking Interview Questions & Answer with Explanation (Part-2)

 Networking Interview Questions 22-43

22. What is HSRP, VRRP & GLBP?

HSRP: (Hot Standby Router Protocol) Link redundancy (Backup Link).

Provides default gateway redundancy using one active and one standby router: Cisco Proprietary.

VRRP: (Virtual Router Redundancy Protocol) Link redundancy (Backup Link) an open-standard alternative to Cisco’s HSRP.

GLBP: (Gateway Load Balancing Protocol) Link redundancy (Backup Link) across gateways. Supports load balancing; Cisco proprietary.

Differences	HSRP	VRRP	GLBP
Standard	No, cisco proprietary	Yes, IETF standard	No, cisco proprietary
Modes Name	Active/ Standby	Master/ Backup	Active virtual Gateway Active Virtual Forwarder
Router Modes	1 active, 1 standby & others listening	1 master others backup	1 AVG and others AVF (all active)
Commands	show standby	show vrrp	show glbp
Default Hello	3 sec	1 sec	3 sec
Load Balancing	No	No	Yes
Default priority	100	100	100

 

23. What is the Routing & Routed Protocol? Give the example of these 2 protocols.

Routing Protocol	Routed Protocol
Routing Protocol is used to distribute routing information across routers on a network. then each one can select best path to  deliver traffic.	A Routed Protocol is a protocol by which data can be routed. (Packet Flow via which protocol).
Routing Protocol Routes a Routed protocol for learning and maintaining Routing table.	Routed protocols are routed by Routing protocols.
Example: OSPF, RIP , EIGRP , IS-IS, BGP.	Example: IPv4 , IPv6, AppleTalk, NetWare, IPX.

 For Details of Question no 22-23 watch this video.

24. Which subnet does host 172.26.70.54/27 belong to?

Answer: 172.26.70.32  its range   (172.26.70.33-172.26.70.62)

25. Write down the port number & function of below protocols

Protocols	Port	Function
SSH	22	Provide remote connectivity in secure way.
Telnet	23	Provide remote connectivity in non-secure way.
DHCP-Server	67	Assigns IP addresses, default gateways, DNS and other network parameters to client devices.
DHCP-Client	68	Gather IP address, Gateway, DNS info from   Server
SMTP	25	used for sending E-Mails.
IMAP	143	used for retrieving E-Mails.
ICMP	7	identify network communication issues.
DNS	53	Resolve the hostname/domain-name  to IP or IP to Hostname
HTTPS	443	send data between a web browser and a website with encryption.
HTTP	80	send data between a web browser and a website without encryption.
FTP	20, 21	File upload/download.
NTP	123	Provide time centrally.

 For Details of Question no 24-25 watch this video.

26. Router & Switch works at which layer?

Router	Switch
Network Layer	Data-Link Layer

 

27. Write some protocols name of Layer-7, Layer-4, Layer-3, Layer-2.

Layer-7	Layer-4	Layer-3	Layer-2
DNS        POP3 IMAP   SMTP HTTP  HTTPS FTP      NTP SSH      Telnet	TCP UDP	IP ARP ICMP RIP IPsec	PPP CDP VLAN VTP STP

 

28. Write down the 3 functions of Layer-2.

3 functions of Layer-2

1.     Physical Addressing. 2.     Error Correction. 3.     Convert bits to Frame.

 

29. Write down the 3 functions of Layer-3.

3 functions of Layer-3

1.     Logical Addressing. 2.     Best Path Selection. 3.     Packet Forwarding.

 

30.  Logical Addressing, Physical Addressing & Port Addressing occurs at which layer accordingly?

Logical Addressing, Physical Addressing & Port Addressing
Logical Addressing	Layer-3
Physical Addressing	Layer-2
Port Addressing	Layer-4

 

31. Write some fields name of TCP packet in Transport Layer.

TCP packet in Transport Layer.

Source Port. Destination Port. Sequence Number. Acknowledge Number.

 For Details of Question no 26-31 watch this video.

32. What is ARP? What is the command to show the ARP table of your PC? What is the command to see CAM table:

ARP (Address Resolution Protocol) & CAM (Content Addressable Memory)

ARP:                                   Find the MAC address from IP Address Command for arp table:   arp  -a To see CAM table:             show  mac-address-table

 For Details of Question no 32 watch these video.

33. Draw a diagram of Server-Client model.

34. Draw a diagram of Peer-to-Peer model.

For Details of Question no 33-34 watch this video.

35. Write down the color code of cross-over cable

36. Write down the color code of straight through cable.

 For Details of Question no 35-36 watch this video.

37. You are designing a subnet mask for the 192.168.9.0 network. You need 3 subnets with up to 50 hosts on each subnet. What subnet mask should you use?

Answer: 255.255.255.192   or  /26

 

38. Do the VLSM from the network block : 172.16.0.0/20

Users: 20,50,180,90,70,2,3,6,49,63,127,80,300,512,51,510

Users	Networks
512	172.16.0.0/22
510	172.16.4.0/23
300	172.16.6.0/23
180	172.16.8.0/24
127	172.16.9.0/24
90	172.16.10.0/25
80	172.16.10.128/25
70	172.16.11.0/25
63	172.16.11.128/25
51	172.16.12.0/26
50	172.16.12.64/26
49	172.16.12.128/26
20	172.16.12.192/27
6	172.16.12.224/29
3	172.16.12.232/29
2	172.16.12.240/30

 For Details of Question no 37-38 watch this video.

39. Configure  OSPF for the 2 networks : 172.16.0.0/25 & 192.168.10.0/26 at area 0.

Configuring  OSPF for area 0.

Router ospf 1 Network  172.16.0.0      0.0.0.127  area 0 Network  192.168.10.0  0.0.0.63    area 0

 

40. Write the command of OSPF configuration on interface g0/1  at area 0

Int g0/1 Ip ospf 1 area 0

 

41. Write the command of EIGRP for the 2 networks : 172.16.0.0/25 & 192.168.10.0/26

Configuring EIGRP

Router eigrp  200 Network  172.16.0.0      Network  192.168.10.0  No auto-summary

 

42. Write the command of RIP for the 2 networks : 172.16.0.0/25 & 192.168.10.0/26

RIP Configuration

Router rip Version 2 Network  172.16.0.0 Network  192.168.10.0 No auto-summary

 

43. What’s the difference between Version 1 & 2 in RIP?

Version – 1	Version – 2
Supports  class full à /8, /16, /24	Supports  class less à /9, /17, /25.
Do not Support password authentication	Support password authentication
Do not support VLSM	Support VLSM

 For Details of Question no 39-43 watch this video.

                                        For more Questions see next post.