Interview Questions for Senior Network Engineer

 Hi All,

I would like to share my interview questions for Senior Network Engineer role in Virtustream company.

Job Designation - Senior Advisor - IT Network Development Engineer.

Company - Virtustream (Dell Subsidiary)

Location - Bengaluru.

Below are list of questions asked during technical round.

Nexus questions :

1. What is the minimum BW required for a VPC peer link

2. what happens if Peer link goes down ? will it impact any servers ? what happen to data plane and control plane traffic

3. What happens if peer keepalive link goes down ?  will there be any impact 

4. Can we keep the peer-keepalive link down for long time ?

5. consider we have VPC configured for a server  with two uplinks of each 10G.  What will be the throughput on the server.

Switching Questions:

6. How RSTP works

7.  What are the steps to create a vlan 100 in switch ?

8.  What command will you use to allow additional vlan  ( id 100 ) to the exiting trunk port where already some vlans are allowed.  

9.  What command will you use to delete a vlan  ( id 100 ) from the exiting trunk port where already some vlans are allowed.  

OSPF Questions:

10. How many ways you can advertise network in OSPF?

11. WHat is the command used to check what are all interfaces participate in OSPF ?

12. How will you t-shoot if the OSPF between two routers are not coming up and stuck in exstart state?

13.   We are running OSPF in a  broadcast environment  with 4 routers.  what will the state of  routers which doesn't elected as DR and BDR routers ?

14. We have configured 2 subnets ( 10.1.1.1/24 & 20.1.1.1 /24 )  in OSPF broadcast environment. 

How many DR and BDR will be elected ?

15. you have not advertised a subnet in to OSPF via network and redistribute commands but when you issue  " show ip ospf interface "  command you see one interface was running OSPF , what could be the reason. ? 

16. If we are running two OSPF process in a router. how many database will be mainintined by the router ?

17.  How to advertise routes between one OSPF process to other OSPF process in same router

BGP Questions:

18 , what is mean by VRF lite.  

19.  what mechannism is used by BGP to avoid loop in IBPG and EBGP

20. We have configured loopback IP address in two BGP routers , how ever they couln't establish BGP session , what could be reason. 

ASA Questions:

21. ASA is sending traffic to different interface instead of DMZ interface , what could be the reason ?

22. list out commands to configure active /standby in ASA

23. Explain packet flow in ASA

24. what is identity NAT

25. What are the various types of NAT in ASA

26. we have configured site 2 site vpn  and we observed encrypted packets counts are increasing  at our end , but seeing no decrypted packets . what could be the reason ?

27. In the above same scenario , we see packets are decrypting but not getting encrypted ?  

F5 Questions:

28. What is mean by SNAT in F5

29. what happens if SNAT is not configured

30. what is mean by persistence and its types 

31. what could be reason if we see the F5 standby unit status as disconnected.

******** END ************

Network Engineer Interview Questions

Interview Questions :

1.  Tell about yourself ?

2.  What is the recent incident you faced in your job and how you troubleshoot ?

3.  Can you explain about OSI layers ?

4.  Can you brief the functions of each layers ?

5.  What are the protocols used in each layers ?

6.  What do you mean by routed and routing protocols ?

7.  Can you define link state routing and distance vector routing protocol with examples ?

8.  what is the difference between rip v1 and rip v2 ?

9.  How a neighbor is confirmed in EIGRP ?

10. In eigrp how a router informs that his neighbor is down to other routers ?

11. what is mean by stuck in active ?

12.  How will you clear a route which is in stuck in active state ?

13. what is mean by feassible successor and feasible distance ?

14. can you tell the metric calculation formula in EIGRP ?

15.  What is the difference between EIGRP and OSPF ?

16.  What is the metric used in OSPF and how it is calculated ?

17.  Explain about areas in OSPF ?

18. What is the difference between STUB , NSSA ,and TOTALLY STUB area of OSPF?

19.  what is mean by virtual-link and how many areas can  a virtual link pass ?

20.  How router id is selected in OSPF ?

21. Can we manually set router id , and how it affect the topology ?

22.  Which switch models you worked ?
23.  What is the difference between Cisco 4507 and Cisco 4507 E ?
24.  How data packets are switched in layer 2 ?

Interview Questions with Cisco for post of Network Engineer

Interview Questions with Cisco:-

Hi folks recently i have attended interview with cisco for the post of Network Engineer . So i would like to post the interview questions in by blog. I hope this post will be helpfull for those who are preparing for interview .

   1.        Tell about your job profile ?

   2.       Explain about OSI layers ?

   3.       Do we use OSI layers now ? 

   4.       Explain about ARP works?

   5.       Scenario 1 : Explain how communication between PCA and PCB happens ?

   6.       What is the difference between OSI layer and TCP/IP Protocol?

   7.       What is the difference between TCP and IP ?

   8.       How much you know about RIP ?

   9.       What are the difference between RIPv1 and RIP v2?

   10.   Whether auto-summarisation is enable by default in RIP ? 

   11.   How auto-summarization works ?

   12.   Scenario 2 : How auto summarization works in this topology?

   13.   What do you mean by static routing and Default Static routing?

   14.   What do you mean by routed protocols and routing protocols ?

   15.   What is mean by AD value and Metric Value ?

   16.   How much you know about EIGRP ?

   17.   What is mean by Stuck in Active in EIGRP ?

   18.   What is the method to avoid Stuck  in active state ?

   19.   What is mean by Fessiable Successor ?

   20.   Whether it is possible to have two routes with for same destination ?

   21.   How much you know about OSPF ?

   22.   Explain how OSPF protocol works ?

   23.   How much you know about BGP?

   24.   How HSRP works ?

   25.   How STP protocol works ?

   26.   How is Root bridge is elected ?

   27.   What is the method to manually elect the root bridge?

   28.   What type of NAT you used in ASA firewall ?

   29.   What is the difference between Static Nat, Dynamic Nat and Policy Nat ?

   30.   You are worked in Cisco 6509 catalyst switch , so what is the supervisor engine model supported in Cisco 6509 switch ?

   31.   What type of redundancy you configured in Supervisor engine of your switch ?

   32.   What is mean by SSO mode ?

Cognizant - Interview Questions for Network Admin

Dear all,
       I have attended interview for the post of Network Admin on 31st August 2013. I would like the share the experience with you , that's why i am posting the list of interview questions asked to me.

I am just posting just the technical questions alone

1. What is mean by stuck in active in EIGRP ? 
2. What is mean by Feasible Sucessor ?
3. What  is it located ?
4. What are the metrics used in EIGRP ?
5. What are the default values of Metric ?
6. What is the Multicast address used in EIGRP ?
7. What do you mean by unequal cost load balancing ?
8. what is the formula to calculate metric ?
9. what is the condition for feasible distance ?
10. next come to OSPF , What do you mean by LSA in OSPF ?
11. What are the different states in OSPF ?
12. when will the database description packet gets exchanged ?
13. what are the contents in database description packet  ?
14. What do you mean by Type 6 LSA ?
15. In a site to site vpn how many phases are there ?
16. What are the parameters of Phase 1 ?
17. If the authentication method in phase 1 mismatch ,how will you identify ?
18. How will check the configured Access-List is working or not ?
19. What is the use of having Security Zones in ASA Firewall ?
20. What are the parameters you will check if i cannot able to communicate from inside  n/w to outside n/w through the ASA firewall ?
21. How will you check whether NAT is happening or not ?

ASA Firewall

Hi Readers ,

           Today i am going to post about the Security Appliance ( i.e Adapative Security Appliance )

Cisco Develops Security appliance for all kinds of customers vary from small , medium sized to large organizations.

Various models of ASA firewall :

1. Cisco 5505

2. Cisco 5510

3. Cisco 5520

4. Cisco 5540

5. Cisco 5550

6. Cisco 5580

7. Cisco 5585 X

Functional Overview of a Firewall :

Firewall Mode :
a. Routed Mode -
     
b. Transparent Mode -

-> A transparent firewall, on the other hand, is a Layer 2 firewall that acts like a "bump in the wire," or a "stealth firewall," and is not seen as a router hop to connected devices.
-> Layer 3 traffic, such as IP traffic, cannot pass through the security appliance unless you explicitly permit it with an extended access list.
->  The only traffice can pass through transparent firewall is ARP traffic which can be controlled by arp inspection
  

Steps to Configure Site to Site VPN

R1(config)#crypto isakmp enable
R1(config)#crypto isakmp policy 1
R1(config-isakmp)#authentication pre-share 
R1(config-isakmp)#encryption aes
R1(config-isakmp)#hash sha
R1(config-isakmp)#group 2
R1(config-isakmp)#exit
R1(config)#crypto isakmp key 0 address 10.0.0.1 0.0.0.0
R1(config)#crypto ipsec transform-set yasser esp-aes esp-sha-hmac 
R1(config)#crypto ipsec security-association lifetime seconds 86400
R1(config)#ip access-list extended ramzy
R1(config-ext-nacl)#permit ip 172.16.0.0 0.0.255.255 192.168.10.0 0.0.0.255
R1(config-ext-nacl)#exit
R1(config)#