Common Cisco Interview Questions and Answers

Interview Questions
  1. What is Recovery Testing

    Ans: In software testing, recovery testing is the activity of testing how well the software is able to recover from crashes, hardware failures and other similar problems.

  2. Which layer is responsible for determining if sufficient resources for the intended communication exists?* Application

    * Network
    * Session
    * Presentation
    * TransportAns:The Application layer of the OSI model is where users communicate to the computer. The Application layer is responsible for identifying and establishing the availability of the intended communication partner and determining if sufficient resources for the intended communication exist.

  3. What are the 2 functions of the Data Link Mac layer?* Handles access to shared media
    * Manages protocol access to the physical network medium
    * Provides SAPs for higher level protocols
    * Allows multiple devices to uniquely identify one another on the data link layerAns: Handles access to shared media and Allows multiple devices to uniquely identify one another on the data link layer
  4. Describe End to End network services: (Choose all that apply)* Best Route selection
    * Accomplished Segment by Segment, each segment is autonomous
    * Flow Control & Data Integrity
    * Best efforts packet deliveryAns: Accomplished Segment by Segment, each segment is autonomous and Flow Control & Data Integrity (Not sure! Double check!)
  5. Which of the following provide correct information about a protocol at the transport layer of the OSI model?* UDP – Provides Connectionless datagrams service
    * TCP – Provides Connection Oriented Services
    * SMTP – Provides Mail Exchange
    * IP – Route determination
    * FTP – Transfers of FilesAns: UDP – Provides Connectionless datagrams service and TCP – Provides Connection Oriented Services
  6. Which layer is responsible for providing mechanisms for multiplexing upper-layer application, session establishment, and tear down of virtual circuits?* Session
    * Network
    * Physical
    * Transport
    * Application
    * PresentationAns: Transport Layer
  7. Which of the following are logged when IP access list logging is enabled?* source address
    * protocol
    * source port
    * destination address
    * access list number
    * destination port
  8. What is the default CDP holdtime in seconds for Cisco routers?* 30 seconds
    * 180 seconds
    * 90 seconds
    * 60 secondsAns: 180 Seconds
  9. Which two of the following protocols are used at the Transport layer?* ARP
    * UDP
    * ICMP
    * RARP
    * TCP
    * BootPAns: TCP and UDP
  10. Choose three reasons why the networking industry uses a layered model:A* It facilitates systematic troubleshooting
    B* It allows changes in one layer to occur without changing other layers
    C* It allows changes to occur in all layers when changing one protocol
    D* It clarifies how to do it rather than what general function to be done
    E* It clarifies what general function is to be done rather than how to do itAns: A, B, and E
  11. Which layer is responsible for identifying and establishing the availability of the intended communication partner?* Application
    * Presentation
    * Transport
    * Session
    * NetworkAns: Application
  12. What is TACACS? Radius?Ans: Terminal Access Controller Access-Control System (TACACS) is a remote authentication protocol that is used to communicate with an authentication server commonly used in UNIX networks. TACACS allows a remote access server to communicate with an authentication server in order to determine if the user has access to the network.RADIUS: Remote Authentication Dial In User Service (RADIUS) is an AAA (authentication, authorization, and accounting) protocol for controlling access to network resources. RADIUS is commonly used by ISPs and corporations managing access to Internet or internal networks across an array of access technologies including modem, DSL, wireless and VPNs.
  13. What is flow or netflow?Ans: NetFlow is an open but proprietary network protocol developed by Cisco Systems to run on Cisco IOS-enabled equipment for collecting IP traffic information.
  14. What is SPAN or RSPAN?Ans: Switched Port Analyzer. Remote Switched Port Analyzer. You can monitor traffic flowing to a port from another port.
  15. What is VMPS?Ans: The VLAN Membership Policy Server ( VMPS ) makes it possible to use a client/server architecture to manage dynamic VLAN based on the MAC addresses. When someone connects to a port, the client switch connects it to server VMPS to know if this MAC address can be connected to this port.