Interview Fundas

The “ipx delay number” command will allow an administrator to change the default settings. What are the default settings?

a) For LAN interfaces, one tick; for WAN interfaces, six ticks

b) For LAN interfaces, six ticks; for WAN interfaces, one tick

c) For LAN interfaces, zero ticks; for WAN interfaces, five ticks

d) For LAN interfaces, five ticks; for WAN interfaces, zero Ticks

answer: A

The default is–for LAN interfaces, one tick; for WAN interfaces, six ticks

What is the maximum hop count for IP RIP?

a) Infinity

b) 16

c) 15

d) 1

answer: C

16 is the maximum hop count, underscoring the size limitation of RIP.

A system administrator, you type “debug ipx sap” and receive the following lines as part of the IOS response: type 0×4, “HELLO2″, 199.0002.0003.0006 (451), 2 hops type 0×4, “HELLO1″, 199.0002.0003.0008 (451), 2 hops What does “0×4″ signify?

a) That is a Get Nearest Server response

b) That it is a General query

c) That it is a General response

d) That it is a Get Nearest Server request

answer: A

Identify the protocol to test connectivity without configuring any layer 3 protocols?

a) TCP

b) Ping

c) IP

d) CDP

e) Telnet

answer: D

CDP can be used to verify connectivity prior to any layer 3 protocols being configured.

Identify 3 characteristics of the Network layer (OSI layer 3)?

a) Connection oriented

b) Path determination

c) Supports multiplexing

d) Manages sessions

e) Packet forwarding

answer: B C E

The network layer is responsible for routing which entails learning the paths, selecting the best path and forwarding the packet. Because it services multiple layer 4 protocols it multiplexes.

Identify the number range for IPX SAP filters?

a) 900 - 999

b) 1000 - 1099

c) 800 -899

d) 100 - 199

answer: B

The IPX SAP filtering range is 1000-1099.

Sequence and acknowledgement numbers are used for?

a) Layer transitioning

b) Flow control

c) Port number addressing

d) Reliability

answer: D

TCP uses sequence numbers and acknowledgements to implement reliability.

Identify 3 IP routing protocols?

a) RIP

b) AURP

c) OSPF

d) IGRP

e) ARP

f) ICMP

answer: A C D

AURP and ICMP are not routing protocols.

Identify 2 features of X.25?

a) Supports only IP

b) Utilizes switched and permanent virtual circuits

c) Contains minimal flow control and error recovery

d) Utilizes LAPB as it’s data-link protocol

answer: B D

X.25 utilizes LAPB and uses switched and permanent VC’s. It supports multiple layer protocols and is heavy laden with error detection and correction mechanisms.

Identify the type of routing protocol that maintains a topological database of the network?

a) Topological state

b) Shortest Path First

c) Link state

d) Distance vector

answer: C

Link State routing protocols maintain a database that lists all the networks in the internetwork.

Which OSI layer performs code conversion, code formatting and encryption?

a) Physical

b) Data-Link

c) Application

d) Transport

e) Presentation

f) Network

answer: E

Layer 6 the Presentation layers performs this function.

Identify the hardware component that stores the bootstrap program?

a) ROM

b) NVRAM

c) Booter load

d) RAM

e) Flash

answer: A

ROM contains the boot strap code.

Identify 3 characteristics of a connection oriented protocol?

a) Path determination

b) Flow control

c) Acknowledgements

d) Uses hop count as metric

e) 3 step handshake

answer: B C E

Connection oriented protocols must first establish the connection (3 step handshake), employ methods to acknowledge the receipt of data (acknowledgements) and slow down the flow of data if required (flow control).

What does CIDR stands for?
A. CIDR (Classless Inter-Domain Routing) is a way to allocate and specify the Internet addresses used in inter-domain routing
B. Classless internet domain routing (CIDR), if default routing this is very useful where we don't need to very much about what is the subnetting about that class of IP's.

What is a Bridge? When is it used? How is a bridge configured? What are the software and hardware components?
A bridge is a layer 2 device - it works based on MAC address. Bridge is s/w
based. It is usually used to bridge 2 networks (or even more in recent times)
Bridge is configured by having the MAC address of the switches connected
directly to it.

Can we use static and dynamic routing in one network?
We can use static and Dynamic Routing in one network. However Dynamic Routing is used to have the best path no matter what the status of the physical links. All routing protocols have some sort of shortest-path or lowest-cost or best-choice algorithm to help you weigh all the options available. Static routing can be used in a small network to reduce the work of the network administrator or to use a particular route only to forward the packet; we need Static routing.

What are the advantages and disadvantages of the three types of routing tables?
The three types of routing tables are fixed, dynamic, and fixed central. The fixed table must be manually modified every time there is a change.
A dynamic table changes its information based on network traffic, reducing the amount of manual maintenance.
A fixed central table lets a manager modify only one table, which is then read by other devices. The fixed central table reduces the need to update each machine's table, as with the fixed table.
Usually a dynamic table causes the fewest problems for a network administrator, although the table's contents can change without the administrator being aware of the change.

What is BGP (Border Gateway Protocol)?
It is a protocol used to advertise the set of networks that can be reached with in an autonomous system. BGP enables this information to be shared with the autonomous system. This is newer than EGP (Exterior Gateway Protocol).

What is autonomous system?
It is a collection of routers under the control of a single administrative authority and that uses a common Interior Gateway Protocol.

What is ICMP?
ICMP is Internet Control Message Protocol, a network layer protocol of the TCP/IP suite used by hosts and gateways to send notification of datagram problems back to the sender. It uses the echo test / reply to test whether a destination is reachable and responding. It also handles both control and error messages.

What is difference between ARP and RARP?
The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used by a host or a router to find the physical address of another host on its network by sending a ARP query packet that includes the IP address of the receiver.
The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its physical address.