Welcome to Top NOC Technician Interview Questions and Answers. Network Operations Center Technician is a role in which network related issues are resolved as part of Network Support Team.
As NOC Technician it is important to have experience and knowledge of networking and its component functions. Different types of NOC positions are related to Computer Networking, Telephony and VoIP.
Majority of questions will be related to technical aspects and random difficulty order. If you are interested in other (non-technical) “Most Common Interview Questions” follow the link below.
For those interested in a Study Guide follow this link (affiliate link).
1. Can you tell me about yourself?
For this question make sure you talk about your experience related to this job position. Employer wants to know if you qualify for this position and your answer will dictate the flow of following questions. This is your first chance to sell yourself to this employer and you can think of it as Verbal Cover Letter.
2. What is Ping?
Ping Command is used to determine connectivity between client and server.
Example using CMD: “ping microsoft.com” will yield results of successful packet transfer or failure. Of course, ping can provide additional information related to status of remote computers.
3. Do you know what BGP is?
4. How would you explain what TCP/IP is?
TCP is a Transmission Control Protocol over Internet Protocol that controls the establishing of connections between computers. In other words it act as the highway for data packets being sent back and forth used by various Protocols like HTTP or FTP. In addition, TCP also deals with sorting out data packet receive order.
5. Can you explain what VLAN is?
At the data link layer of OSI model, Virtual LAN (Local Area Network) is typically setup in broadcasting domain environments in which it can act as an additional network that is attached to physical. Meaning, that this network is actually virtual for the purpose of keeping different aspect of various applications separate from physical network. For example; physical network can have multiple switches with hosts attached that form multiple physical networks; in this case, using VLAN (software) you can group all hosts attached to multiple switches and create one standalone network.
6. Would you consider yourself as a team player?
When working as NOC Technician you will spend time working with other employees and teams that will require your to be a good team player. If needed provide an example of a project completed along side coworkers.
7. What is a proxy?
Proxy servers are designed to filter network traffic in order to prevent access to certain websites and it can monitor user web activity. Also, proxy server can hide origin IP from the outside networks. For example; in business environments your computer IP address will be unique to your local network while the internet will see another/different ip address used by proxy server.
8. Let’s say a host computer cannot be reached over the local network using the host name but can be reached using an IP address, what do you think the problem is?
In order to confirm the answer to this question you can follow up with another question to show your troubleshooting method; however, this issue is most likely caused by DNS (Domain Name System) configuration. Chances are that the host name is not added to DNS server and therefore network does not recognize host name but rather IP address locations.
9. What is DNS?
DNS stands for Domain Name System and it provides a database association with various information related to domain entities. For example, a computer attached on physical network will have a an IP address which is then translated to a host name by DNS server. Instead of typing out an IP Address to reach a computer on the network you can simply remember the host name and DNS will handle the routing. This is how website names work…
10. What is a Network Switch?
A Network Switch is a device that creates a network in which multiple devices are connected and share data. This is accomplished by receiving, processing and forwarding of data in form of data packets.
11. How would you find the up time in Cicso switch/router?
When using CLI SSH/Telnet session you can use command sh ver to show uptime.
12. If you came across a situation in which you could not resolve an issue, what would you do?
In this case, interviewer is once more asking if you are a team player which means that the correct answer is to ask someone else in your group for assistance.
13. Can you explain a 3 Way Handshake?
1. Client Sends Synchronize Request.(SYN)
2. Server Responds With Synchronize Request and Acknowledgment.(SYN, ACK)
3. Client Responds With Acknowledgment.(ACK)
14. What is Trunking?
Trunking is a networking system that provides access to multiple clients/customers without having to run separate connections for each (telephony). For example, a business will have multiple phone lines that are connect to a Trunk Network Connection.
15. Have you ever found yourself in a situation that required a decision in which risk for failure was high?
You can answer this question with an example of personal experience. In other words, you can provide a situation in which you resolved an issue that required a major system change or configuration. Of course, your answer will be different from others.
16. Do you know what EIGRP Convergence Time is?
Also known as Enhanced Interior Gateway Routing Protocol convergence time refers to how long a router will consider a host alive without receiving any data packets. In most cases the hold time is set to three times the hello interval, by default, 15 seconds and 180 seconds. The settings can be adjusted from within the router.
17. How would you test delay and route of packets between two connections?
You can perform a traceroute test in order to test connectivity and packet delay over Internet Protocol. An example of this is CMD command “tracert” after which you can see each node jump and latency with information about each route taken.
18. What is Route Poisoning?
Route Poisoning is a way to stop routers from sending data packets through routes that no longer exist on the network. In order to exclude routes from routing table, networks can use route poisoning to inform the other routers on the network of invalid or non-existent routes. This method prevents unnecessary data packet sending over the network.
19. How would you identify which PC and what Port it’s using on the network?
You can do so by looking at ARP and MAC Address table from within a switch.
20. Why should we hire you?
This is your last chance to talk about your experience and qualifications in order to get this awesome job. Feel free revisit the first question asking about yourself.
Thank you so much for reading this tutorial. Keep in mind that it’s impossible to know exactly which questions will be asked during an interview. What matter is that you go in with a quick knowledge refresh which will give you the confidence and much needed support for your interview.
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