Networking interview questions to ask a Graduate

[Dr_Weasel]

Im after some advice and you technical folks may be able to help me.

I work for a carrier grade VOIP telecoms manufacturer in the support side of the organisation. Over the last 8 years I've been there we have only really employed heavily experienced people. However next week we are interviewing some graduates for some more junior support posts

I've never really had to interview a graduate before. I've only had to interview people with at least 3 years worth of relevant technical. Obviously its easier to grill someone about something they profess to know on their CV and find out what they really do know about the subject. However with graduates straight out of Uni I'm unsure as to the level of technical networking and IP routing knowledge I can reasonably expect them to know. For example one guy last week who had Unix on his CV couldn't even correctly tell me the command used to get a directory listing...

So what sort of level of knowledge can I expect a computing degree level graduate to have of IP networking and routing? Does anybody have any thoughts on questions I can grill them on to root out the blaggers from the people that really know?

 

[Kryten]

Depends on the specific backgrounds - most courses will obviously centre on the theory of a subject and any physical exposure is through virtualisation, simulation and maybe work experience type assignments.

So if they've just come from a particular course that does centre on networking, expect them to be able to convert binary to hex on a whim and how many repeaters you need when running CAT5 over a 4km site, but possibly not be very good at physically patching & making cables, or why the fan in a Catalyst router is smelling like a rotting fish and not moving at all/much.

Of course this experience will differ between universities or other establishments - from what I've seen, identical courses on identical curriculums differ so much in their implementations between educational establishments that no two students/graduates are the same. Naturally in these circumstances, you'll get far better all round graduates from those with hands on experience, placements and the like.

Might be worth vetting some of the unis themselves to get an idea of how their courses work before interviewing so you've a headstart on them

Or of course see if you can find some students to get an idea. May well be some on here.

 

[Bob007]

Dunno about questions but i'll tell you about some bloke i worked for once. Might help.

He use to interview everyone that hoped to be employed by the company. He had a system. He had 10 laminated cards. On each card he had 10 or so questions. He had these cards graded 1 to 10. 1 being stuff you'd expect a child to know, Whats a keyboard/usb/vdu that kinda of stuff. 10 was realy hard stuff, useing scenarios and all sorts of technical jargon most ppl would cry at. rest sort of built up from 1 to 10. During the interviews he would ask a question. Depending on how he felt about the peep in front of him he would pick a card that sort of suited what he thought their lvl was at. Lets say card 4. He'd ask a question from 4 and see if you got it right. If you did he'd carry on with the interview and then at a random time go to card 5 and so on. What his goal was, was not to see if you could answer the questions but to see if you had the guts to own up and say I don't know. Am not shy. if i don't know, I will say I don't know and endevour to find out. I got a job becuase i didn't know and wasn't affraid to say it. Might want to try that

 

[Dr_Weasel]

Unfortunately Ive been handed some CVs and been told to interview them on Monday. I understand that Unis wont be in much of a position to actually teach anyone anything useful about Solaris or the like, but Im not sure if Im expecting too much for them to even have an understanding of IP routing, subnets, etc or if we really do have to start from scratch. The problem will be is that they will be expected to pretty much work on their own and we dont have any kind of formal training. This is fine for someone with 5 years+ industry experience but the bean counters have now told us to employ some graduates....

 

[ECA]

Unfortunately Ive been handed some CVs and been told to interview them on Monday. I understand that Unis wont be in much of a position to actually teach anyone anything useful about Solaris or the like, but Im not sure if Im expecting too much for them to even have an understanding of IP routing, subnets, etc or if we really do have to start from scratch. The problem will be is that they will be expected to pretty much work on their own and we dont have any kind of formal training. This is fine for someone with 5 years+ industry experience but the bean counters have now told us to employ some graduates....

Hire the most inept fuckers you can find and when the network goes tits up and costs a fortune to fix, you turn around and point to your hastily filed before the end of friday report on why hiring fresh graduates is a terrible idea.

 

[TdC]

Unfortunately Ive been handed some CVs and been told to interview them on Monday. I understand that Unis wont be in much of a position to actually teach anyone anything useful about Solaris or the like, but Im not sure if Im expecting too much for them to even have an understanding of IP routing, subnets, etc or if we really do have to start from scratch. The problem will be is that they will be expected to pretty much work on their own and we dont have any kind of formal training. This is fine for someone with 5 years+ industry experience but the bean counters have now told us to employ some graduates....

I suppose if they're graduates they will be well versed in the usage of google, which, if you are indeed running Solaris is pretty decently covered. Some of which will have even been written by me. Anyway, I would go more for what kind of person you want and how said person works or expects to work in an IT department than the current knowledge of said person specifically regarding Solaris and or networking. If they fail to learn quickly, then torture them until they do or depart.

Hire the most inept fuckers you can find and when the network goes tits up and costs a fortune to fix, you turn around and point to your hastily filed before the end of friday report on why hiring fresh graduates is a terrible idea.

also do this

 

[Cadelin]

Unfortunately Ive been handed some CVs and been told to interview them on Monday. I understand that Unis wont be in much of a position to actually teach anyone anything useful about Solaris or the like, but Im not sure if Im expecting too much for them to even have an understanding of IP routing, subnets, etc or if we really do have to start from scratch. The problem will be is that they will be expected to pretty much work on their own and we dont have any kind of formal training. This is fine for someone with 5 years+ industry experience but the bean counters have now told us to employ some graduates....

Shit situation.

You can't expect a fresh graduate to know specific details about the industry. With a graduate you want to find the smartest, hardest working most adaptable person. Whoever you pick WILL have to learn stuff on the job. Picking somebody who is a lazy idiot but happens to have done a 3 month project in exactly the field you want will not pay off in the long run.

You have 2 choices when it comes to questions:
1) They will have done a project while at uni where they would have actually had to apply what they have learnt. You can ask them in detail about that. The problem here is if the project they did was completely different from what you want them to work on it might not be ideal.

2) Ask them abstract questions. What are the most important features of this type of software? What impact would minimizing x have on y? etc Think up some theoretical problem and see how they handle it.

Don't focus your questions on just one topic.

 

[SilverHood]

The problem with graduates is that most of their knowledge is mostly academic and thus pretty much worthless as soon as you get into a real production environment. I know this first hand since I started a graduate job as a programmer 7 months ago. What you're after is adaptability, learning ability, natural interest and drive.

Give them a hypothetical problem based on issues you have to solve. "Boss is away on holiday in the Sahra, everyone else is off with food poisoning from lasts nigh curry. You've been here for 1 day and XXXXX happens. How do you deal with it?".

What do they do in their spare time. If they don't own a PC, then forget about them.

Then ask about what they know about the industry they are about to enter. Most wont have done any research and you can bin most of those. Eventually you'll end up with a few grains of salt worth something, and you can make a decision from there.

Ask them what they do in their spare time. We had one guy at a place I worked while at college. He said in his spare time, he sat in his room. "In your room?" ... "What do you do in your room?"... "Nothing." .... "Nothing? Read, TV or anything?".... "No, I just sit there for 4 hours, then go to bed."... "What about weekends?"... "I sit for 12 hours on weekends. Sometimes I go outside and sit in the park if the sun isn't too bright."

Oh, and grill the CV If a person says they have experience of using something, ask them to give examples. We're full of shit!

 

[lecter]

I dont often post here or give sensible responses when i do but I will in this case. I truly pity you having to interview a graduate for a networking position because it really is so far removed from corporate networking.

I would be looking for intelligence, enthusiasm and problem solving. It is also important to ask open questions otherwise you'll be in for some uncomfortable silences.

Most IT graduates should be familiar about DSL/bittorrent whatever. So ask them about it. Do they have a opinion on internet in the uk? Do they have any idea how it is going to be changing. If they're a geek they'll know.

The most basic formal question is the 7 Layer OSI model. I would not expect the person to know all of the layers (and I would tell them this). However I would expect to know why it is in existence. The point i'm looking for here is interoperability between vendors with a well defined interface between the layers. If they know the seven layers they've done their homework. Bonus++ if they mention that each layer is encapsulated

Layer 2 vs Layer 3

Difference between a HUB/Switch/Router. They should know how a switch learns the physical addresses and stores it in a table (ARP). I'd draw a diagram of a network that is broken. I.E. a 3 switch in a triangle so to create a loop. I would expect them to know that is a bad idea and spanning tree fixes it. I'd then draw a fully meshed network with a single endpoint and start point. I'd get them to draw a traffic flow from one side of the page to the other. At this point they will probably draw a single line. I would tell them that this is indeed what ethernet does but is it ideal? Whats the best ideal solution? You can draw analogies betweens cars motorways and roads. Answer you're looking for is loadbalanced across all the wires. This is a layer 3 network because it loadbalances across paths of equal cost. Infact cisco gear all odd IP's go down one path and all even to the other path.

Tough questions perhaps. But they are just basic common sense in reality.

 

[Dr_Weasel]

Cheers for the ideas guys. Very helpful.

Had a bunch of interviews yesterday. One guy with Linux and IP on his CV admitted in the end hes only ever really booted Linux up a couple of times and couldnt tell me the difference between a switch and a hub.

One guy though has off his own back been doing CCNA certification and has his exams for it coming up. He seemed pretty dam clued up. I think we have a winner!