NOC Engineer interview questions | Network Engineering

Summary

In this informative video, Ali shares his extensive experience in Network Operation Center (NOC) engineering, offering valuable insights for aspiring NOC engineers preparing for interviews. He covers essential topics such as understanding the OSI model, TCP/IP, UDP, and troubleshooting techniques. Ali emphasizes the importance of a troubleshooting mindset, collaboration, and quick thinking under pressure. He also addresses common interview questions and provides guidance on how to approach them, ensuring viewers are well-prepared for their NOC engineering interviews.

Takeaways

• 😀 The speaker, Ali, has been busy with work and makes videos as a side hobby to help people with questions.
• 🔍 Ali's previous video was about the life of a NOC (Network Operation Center) engineer, which sparked many interview preparation inquiries.
• 🔧 Ali shares his decade-old experience with NOC engineering interviews to assist those preparing for similar roles.
• 📝 NOC stands for Network Operation Center, where engineers monitor and troubleshoot networks, with varying scopes depending on the company.
• 💡 The key to NOC interviews is demonstrating a troubleshooting mindset, as this is the primary skill NOC engineers are paid for.
• 👨‍🏫 Ali suggests replicating problems in a sandbox environment and using packet captures as part of the troubleshooting process.
• 📈 Understanding the OSI model's seven layers is crucial for NOC engineers, as it dictates where to start troubleshooting based on the issue.
• 🤝 Teamwork is essential in a NOC environment, with engineers often needing to guide junior staff or seek help from seniors.
• 🛠 Technical knowledge of networking protocols, such as TCP/IP, UDP, and the functions of network devices like switches, is expected.
• 📋 Ali emphasizes the importance of knowing how to collect the right logs and traces to effectively troubleshoot network issues.
• 🗣️ Behavioral questions are also part of the interview process, testing candidates on their problem-solving approach and team player attitude.

Q & A

What does NOC stand for in the context of the video?

NOC stands for Network Operation Center, which is where network monitoring and troubleshooting are performed for a company or globally, depending on the scope of the job.

Why is the OSI model important for a NOC engineer?

The OSI model is crucial for a NOC engineer as it provides a framework for understanding the seven layers of networking, which is essential for troubleshooting and resolving network issues at the correct layer.

What are the seven layers of the OSI model mentioned in the video?

The seven layers of the OSI model are the Physical layer, Data Link layer, Network layer, Transport layer, Session layer, Presentation layer, and Application layer.

Why is troubleshooting a key skill for NOC engineers?

Troubleshooting is a key skill for NOC engineers because their primary job is to identify, analyze, and resolve network issues. Having a systematic troubleshooting mindset is critical for effective problem-solving.

What does the acronym TCP/IP stand for and why is it important for NOC engineers?

TCP/IP stands for Transmission Control Protocol/Internet Protocol. It is important for NOC engineers as it is the fundamental communication protocol used for transmitting data over the internet, and understanding it is essential for diagnosing connectivity issues.

What is the difference between TCP and UDP as mentioned in the video?

TCP (Transmission Control Protocol) is a connection-oriented protocol that ensures reliable data transmission, while UDP (User Datagram Protocol) is a connectionless protocol that allows for faster transmission but without the guarantee of delivery or order.

Why is being a team player important in a NOC environment?

Being a team player is important in a NOC environment because engineers often need to collaborate, share knowledge, and provide mentorship to junior staff. Effective teamwork is crucial for managing and resolving complex network issues.

What is a proxy and why might it be used in network environments?

A proxy is a server or application that acts as an intermediary for requests from clients seeking resources from other servers. It is used to improve security, manage network traffic, and provide access control in network environments.

What is a three-way handshake in the context of the video?

A three-way handshake is the process of establishing a TCP connection between a client and a server, involving the exchange of SYN (synchronize), SYN-ACK (synchronize-acknowledge), and ACK (acknowledge) packets.

What does the term 'trunking' refer to in networking, as mentioned in the video?

Trunking in networking refers to the practice of carrying multiple virtual local area networks (VLANs) over a single physical link, allowing for efficient use of bandwidth and better organization of network traffic.

How can a NOC engineer find the uptime of a Cisco router as discussed in the video?

A NOC engineer can find the uptime of a Cisco router by using the 'show version' command in the command-line interface (CLI), which provides information about the router's operating system version and how long it has been running.

Outlines

00:00

🎥 Introduction to NOC Engineer Interview Preparation

Ali, the host of the channel, returns after a month-long hiatus due to work commitments. He discusses the importance of his side project, which is to help others by answering questions and sharing experiences. His last video on the life of a network operations center (NOC) engineer received positive feedback, prompting him to share insights on how to prepare for NOC engineering interviews. Ali emphasizes the need for interviewees to showcase a troubleshooting mindset, which is critical for NOC roles. He shares his own experience from 10 years ago and offers to guide viewers on how to approach such interviews, covering various levels of NOC positions.

05:01

📚 Essential Knowledge for NOC Engineer Interviews

The speaker advises viewers to be well-versed in the OSI model's seven layers, which are fundamental for NOC engineer positions. He explains the relevance of each layer in network troubleshooting and emphasizes the importance of knowing where to start when diagnosing issues. Ali also discusses the significance of understanding protocols like TCP/IP and UDP, as well as the role of a proxy in network environments. He stresses the importance of being a team player and the collaborative nature of working in a NOC, including mentoring junior engineers and seeking help from senior team members when needed.

10:02

🛠 Technical and Behavioral Aspects of NOC Interviews

Ali outlines the technical skills and knowledge areas that interviewees for NOC positions should be prepared to discuss, such as the function of network switches, the use of commands to debug gateways, and understanding concepts like the three-way handshake in TCP. He also touches on the importance of being able to think and communicate clearly under pressure, using case scenarios to illustrate common troubleshooting challenges. Additionally, he highlights the need to demonstrate problem-solving skills and the ability to escalate issues when necessary, as well as the importance of behavioral questions that assess a candidate's teamwork and decision-making abilities.

15:03

🗣️ Interview Strategies and Closing Remarks

In the final paragraph, Ali provides strategies for interviewees to handle behavioral questions, such as explaining why they should be hired, by showing enthusiasm and a willingness to learn. He encourages honesty and self-awareness during the interview process, warning against bluffing. Ali also reflects on his own career progression from a NOC engineer to his current role in pre-sales, design, and solution architecture. He concludes by inviting viewers to subscribe, leave comments, and share the video, promising to answer all comments and engage with the audience.

Keywords

💡Network Operation Center (NOC)

A Network Operation Center (NOC) is a central hub where network operations and management are conducted. It is responsible for monitoring and troubleshooting an organization's network infrastructure. In the video, the speaker discusses how NOC engineers are expected to have a troubleshooting mindset, which is critical for their role in maintaining network performance and reliability.

💡Troubleshoot

Troubleshoot refers to the process of identifying and resolving issues within a system. In the context of the video, the speaker emphasizes the importance of a troubleshooting mindset for NOC engineers, as they need to quickly identify and fix network issues to minimize downtime.

💡OSI Model

The OSI Model, or Open Systems Interconnection Model, is a conceptual framework used to understand how data communications are performed in a network. It consists of seven layers, each with specific functions. The speaker mentions the OSI Model as a fundamental concept that NOC engineers should be familiar with, as it helps in understanding where to start when troubleshooting network issues.

💡TCP/IP

TCP/IP stands for Transmission Control Protocol/Internet Protocol and is the fundamental communication protocol used for transmitting data over the internet. The video script discusses the importance of understanding TCP/IP for NOC engineers, as it is a core protocol for network communication and a common area of focus during network troubleshooting.

💡UDP

UDP, or User Datagram Protocol, is a communication protocol that offers a limited service for sending messages without establishing a connection between the communication partners. In the video, the speaker might differentiate between UDP and TCP, highlighting the differences in how they handle data transmission, which is crucial knowledge for NOC engineers.

💡Packet Capture

A packet capture is the process of intercepting and recording all or part of the data that is transmitted over a network link. In the script, the speaker mentions running packet captures as part of the troubleshooting process, which helps in analyzing the data packets to identify issues within the network.

💡Sandbox Environment

A sandbox environment is a secure, isolated area where programs can be tested without affecting the production environment. The speaker in the video describes using a sandbox environment to replicate problems, which is a common practice in troubleshooting to safely test potential solutions before implementing them in a live network.

💡Intermittent Problems

Intermittent problems are those that occur sporadically and are difficult to diagnose because they do not happen consistently. The video script discusses the challenge of troubleshooting intermittent issues, which requires a systematic approach and often the use of tools like packet captures to identify the problem.

💡Mentorship

Mentorship refers to the guidance and support provided by a more experienced individual to a less experienced one. In the context of the video, the speaker talks about the importance of mentorship in a NOC environment, where senior engineers may need to guide and assist junior staff in resolving complex issues.

💡Three-Way Handshake

The three-way handshake is the process of establishing a connection between a client and a server in a TCP/IP network. It involves the exchange of SYN (synchronize), SYN-ACK (synchronize-acknowledge), and ACK (acknowledge) signals. The speaker in the video may explain this concept as part of the foundational knowledge required for understanding network communication protocols.

💡Trunking

Trunking in networking refers to the practice of grouping multiple communication channels together to be transmitted over a single physical channel. The script might mention trunking as a technique used to increase efficiency in data transmission, which is a concept that NOC engineers should understand when dealing with network configurations and optimizations.

Highlights

Ali shares his experience of working in a NOC (Network Operation Center) and offers advice for interviews.

Importance of understanding the OSI model's seven layers for NOC engineers.

The necessity of having a troubleshooting mindset in NOC roles.

Replicating problems in a sandbox environment as a troubleshooting approach.

The challenge of dealing with intermittent network issues and the use of packet captures.

The pressure of troubleshooting under time constraints with senior management involved.

Ali's personal development of a 'thick skin' for handling high-pressure situations.

The significance of being well-prepared for NOC interviews with technical and non-technical skills.

Questions about TCP/IP, UDP, and the difference between them expected in NOC interviews.

The role of a team player in a NOC environment and the importance of mentorship.

Technical questions about network switches, their functions, and basic commands.

How to find the uptime of a Cisco router and the significance of this metric.

Behavioral interview questions about problem-solving and teamwork.

The concept of a three-way handshake in establishing TCP connections.

Understanding trunking and its purpose in network environments.

Identifying PCs and their network ports using ARP and switch MAC address tables.

Behavioral questions about handling high-risk decisions and troubleshooting.

Advice on being honest and showing a willingness to learn during interviews.

Ali's transition from NOC engineer to presales, design, and solution architecture roles.

Transcripts

[Applause]

welcome back to my channel guys this

your boy ali hope everybody's doing good

it's been about a month i haven't made a

video because i've been super busy with

work and of course that's priority um

this is just my side fun that i do and

try to help people out answer some

questions etc

so my most recent video was about

a life of a knock engineer and i got a

lot of feedback and comments and stuff

people asking me um you know how should

they approach or prepare for an

interview and uh you know so i did some

homework and uh just gathered all my uh

experience that i had with the

interviews that i did for the noc

engineering positions and back in my old

days um this was about like 10 years

back

so i just wanted to

like help you guys out maybe uh you know

somebody who's uh trying to go for an

interview and maybe this could help them

out so when you go in for these knock

interviews uh now nox stands for network

operation center and this is where you

work uh and pretty much monitor and

troubleshoot

all the network for the company or

globally et cetera depends who you work

for uh that you know the scope is

different for each so

but these uh questions that i'm about to

address are going to apply to

level 1 level 2 level 3 and even higher

than that so

um

you know i mean if you

if you are going for an interview um i

think this would be a really really good

guide and i think if you

just hit this video and

go for your interview i think you'll

probably do really well enough to get a

job and uh and

and that's uh that's my my two cents

about that now when you do go for an

interview make sure you do prepare a

little bit obviously

you know preparing as in be like you

know be confident you know and stuff

like that the basic stuff that they ask

you you know about your career and your

work experience and why do you want to

work for the company and stuff like that

but make sure you do

understand how to troubleshoot things

because when you work in a knock i think

the number one thing that they're really

trying to find out is that if you have

the troubleshooting mindset because

they could hire any

straight out of school

person with no experience and just train

them how to disable alarms or check

alarms and stuff like that but

but what

the noc engineers really

get paid for is

is how they troubleshoot right so let's

say if a gateway or a site does go down

how do you proceed right how do you

what's your step one what's your step

two how do you they want to they want to

know how you what's your thinking

process behind

troubleshooting now

you know in my case i would always try

to replicate the problem in like a

sandbox environment um so if i could

replicate it most likely i could you

know keep working on it and uh you know

i'll find a resolution but a lot of

times

problems are intermittent or sporadic so

it's really really hard to catch them so

then you have to run uh packet captures

on gateways and stuff but

that's besides the topic but i think the

main thing they want to really know is

that um

your level of understanding of how

you're going to proceed with

troubleshooting because uh in my

experience when i was working in the

knock um you know a client would call

and be like hey her network just went

down

and we're there managed services

provider so i'm i'm in the knock

and uh you know i would get an email or

something or or maybe you know and then

i would call the client up or they would

call me and be like hey can you just

help us out you know this and that so

now these people who are calling you are

senior management or middle management

people and they're really responsible

for bringing that network up in the

shortest amount of time

so what you have to do is pretty much

jump on the call with them uh do a web

conference uh so what i would do is send

them a webex cisco webex or you could do

zoom or whatever else screen share um so

they would join the call and then it

would be me maybe a couple other people

on their team that are responsible for

different stuff sometimes i don't have

access so they have you know they give

me access to log in and troubleshoot and

stuff so now this could be very very

nerve-wracking because um

you know it's a down situation and the

client could be losing a lot of money

and you just have to kind of be at your

a-game and

be very comfortable and you have to be

able to think under pressure

and to be able to resolve the problem

and and bring their network back up and

and you know i've done this

for so many years that i feel like

um i've built that um thick skin

uh where i'm

comfortably able to do that uh if i had

to back in my back when i was working in

a knock uh so

so yeah i mean i just wanted to share my

experience with you guys so before we

waste time let's jump right into it now

of course the first thing i recommend

you have

you know down pack is the seven

layers of the osi model model now what

are the seven layers of course um i mean

if you are applying for a noc engineer

level position then you should know this

without a doubt and i'll go through them

right now so level one is physical then

you got the data link and then you got

the layer three is network and then you

got the

transport

and then session

presentation and application now most of

your network stuff is on layer three and

if you're doing a lot of you know mostly

switching and and network stuff it's

mostly um on the data link or or the

network level which is layer two and

three and sometimes it's rarely ever

where you might have to send the client

into their data center to make sure the

cables are okay but that's like super

rare so layer two layer three you're

pretty much logging to these gateways

and you know

running packet analysis and traces and

everything collecting logs and checking

them and making sure the

tcp and udp messages are sending what

they're supposed to to server client and

you know how the setup is according to

the current infrastructure now this is

just basic but like

like if you work on databases and stuff

they communicate on different levels and

uh you know depending on what the

problem is you have to know where to

start troubleshooting so

a lot of times if you don't know where

to start you end up capturing wrong logs

and then

you're like sitting through those logs

you're not going to find anything

because obviously you didn't even

capture the right ones and a lot of

times these servers are not constantly

logging so you have to make sure they're

set to detail level of logging otherwise

you're again not going to see anything

because if you keep running detailed

logs over and over all throughout the

day and for

forever you're obviously going to bog

down the servers and you're going to

bring everything down so you just have

to make sure that you know

you

know what you're doing just make sure

you are collecting the right ones

because obviously um

you know that's the key because once you

collect the right traces it takes hours

to be able to determine if the problem's

there now a lot of times you might have

to collect traces from from like five

different places depends on where the

packet ended up or where the packet

dropped or whatever the case is right so

um but

the basics is that you have to be able

to um collect the right traces

but yeah know your osi model i mean

seven layers they're without a doubt are

gonna

drill you down on that

and uh of course network is you know

all your protocols on the network level

which is ip icmp ipsec igmp and packets

how the packets work um data link which

is your switching how the ethernet ppp

switch so of course you know you're

gonna they're gonna ask you can you tell

me about yourself so here you want to

talk about

your strong points obviously you want to

tell them a little bit about yourself

you want to tell them your work

experience that's related to the job

you're applying for you don't want to go

rambling about

stuff that's unrelated or things you

have done

that doesn't relate to this job

because that that will just simply

disqualify you so you have to make sure

when they ask you that question tell me

about yourself you have to relate it to

the current position that you're

applying for

so of course you got to know what a ping

is right and

why the ping command is used to check

connectivity between a client and server

and stuff like that so

definitely that's going to be one of the

questions

so what is tcpip

what is udp what is tcp

what is the difference between them and

they might ask you hey um you know which

protocol is used if you're

uh running packet analysis between these

two

um servers and you know what kind of

messaging

protocol are they using they might just

ask you in in that sense as well

um

and then

you know being being a team player is a

huge part of working in a knock because

um

a lot of times you may

run into

depending on your company

you know a lot of junior level engineers

are going to come up to you at random

times when you're busy

and they're going to need guidance and

and you have to help them out you have

to actually walk walk over to their desk

and kind of sit down with them and help

them out so that's going to be a lot of

mentorship you're going to have to do

if you're on the escalation level but

if you're on level 2 and you know you do

need help you could go up to the seniors

and

go to the level three guys and they'll

definitely help you out right so there's

a lot of collaboration and and uh going

back and forth and a lot of teamwork

that you have to be a part of because

not everybody knows everything but i'm

sure somebody else does that sits next

to you or something so

constantly um you know you have to also

show in the interview that you're a team

player so they might ask you questions

about what is a proxy and what what's

the function of a proxy and why is a

proxy

used in certain

network environments and stuff like that

um you know so make sure you know what

that is and

they might they might throw uh like a

case scenario where let's say a host

computer cannot be reached over a local

network using a host name but can be

reached using an ip what do you think is

a problem now in that case i mean it's a

very basic level

of um

of of question i mean you have to know

the answer for that it's normally

something wrong with the dns right so

you have to go check your c names other

a

aaa records and stuff like that you know

they might ask you uh what is layer 3

what is layer 2

what is a network switch do

um you know

how do you what's the function of a

network switch and they might ask you

basic level stuff they might not like if

you're depending on the level you're uh

interviewing for like level three when i

was applying for they would straight up

ask you hey what command do you run if

you wanna you know uh debug this this is

on the gateway and you know so you have

to know the commands but if you're going

for level two then i think you know they

might just ask you or level one that

what is a network switch and stuff like

that so make sure you know what that is

and uh so how do you

so

how would you find uptime on a cisco

router now that's one of the very basic

thing i mean you could just do a run a

show command and it'll tell you like if

you do show version or there's a few

other commands you can run once you're

logged into um

by telnet or ssh into the router on the

version once you check that it'll tell

you the version but it'll also tell you

what's the uptime up time is pretty much

how long the route has been up um and

how many hours and minutes and so

so that's a very basic question but they

may ask you that so

know that

now they may ask you okay if you run

into a problem where you cannot resolve

a problem what would you do so then of

course you would um you know try to get

help from your peer

or then you would escalate the problem

and and of course they may ask you what

is a three-way handshake so the client

sends a synchronized request

and then a server responds with a

synchronized request and acknowledgement

and then the client responds with the

acknowledgement so it's in synack and

then hack

so that's how that works so

you know

know that

they might ask you what is trunking

now there's all kinds of trunking right

all kinds of circuits trunks so you have

to know what is trunking and what's the

purpose for trunking and stuff like that

now have you ever found yourself in a

situation that required decision in

which

risk

for failure was very high now what

they're trying to really understand here

is that

you know how would you go about

troubleshooting this and how would you

go about

you know

gathering information about this and

they want to know how would you

logically or what's your thought process

you would get into

before you go ahead and start

troubleshooting this type of thing

so

now

now what you want to do is think out

loud because they want to see how you're

thinking what's your thought process so

whatever you're gonna do just be like

hey um so first you know if you need a

no pad or a pen you could tell them and

they would appreciate that because they

know that you're really trying to

answer the question in the best way

possible so

and of course uh you know if you have to

take notes down to understand the

questions and and give them a proper

answer you're more than welcome to do

that that's well uh that's welcomed into

job interviews now they might ask you

how would you test delay and route of

packets between two connections

um i mean you know trace route is one of

the

commands

uh that you would you know constantly

use and you're pretty much you know

um using that you probably use that on

cmd in windows is a similar command

tracer t but you could

you know you could use traceroute on the

cisco cli as well to

you know test connectivity between two

endpoints

so and how the you know route packets

route back and forth and you could test

delays and stuff

so know that that's pretty basic too

now how would you identify which pc and

what port

it's

using on the network uh okay that's a

good question so they might ask you hey

how do you know how do you figure out

what port

you know that pc or or that workstation

is on so you know you could look that up

simply by using harp

which is address resolution protocol

and

you know

you could

log into the switch and um pretty much

get the mac address table from the

switch

so there's a couple of ways to do that

but

that might be a part of the question

that

they may ask as well

now of course they're going to ask you

now these are the technical questions

that i just went over but they're going

to ask you some behavioral questions and

they might ask you

why should we hire you and stuff like

that now when when they ask you that um

make sure you show them

enthusiasm and you make sure you show

them willing to learn um

and if you don't know something tell

them that you know you're a fast learner

and if you are you know don't

don't lie to them you know i

would just be super honest because the

thing is like if you do end up getting

the job maybe you won't like it or maybe

something bad will happen at that job if

you're trying to bluff it through the

interview so make sure

you know all these questions that i'm

telling you i'm just not telling you so

you could go ahead and

try to you know beat around the bush and

get through the interview but actually

go and study these things right because

that might be

part of what you really need to do day

to day in your production level

network so you know

but yeah i mean why should we hire you

that's a great question so make sure you

have a really

um outstanding answer for that that you

know

but

but yeah i mean um so

these are pretty much um just some basic

questions that i came up with that were

asked in my days um now it's been about

10 years so

these are you know these are still

relevant because um

people who are trying to get into the

network field or you know like myself i

started in in the knock

on level two and then work my way up

so now i'm

completely different i'm doing a lot of

um

like

pre-sale stuff and design and solution

architecture and everything but that

took a lot of years

to be able to understand

the back end of things so

so either way um guys

if you haven't subscribed

you know hit the subscribe button if

this video was any help to you um let me

know in comments

and if you have any questions do drop in

the comments i i normally

answer like all the comments uh hit the

bell icon subscribe to my channel tell

your friends about it

and

i will see you guys in a bit