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- 1IP addresses rangesA = (1-127)
B = (128-191)
C = (192-223)
D = (224-239)
E = (240-255) - 2Given the classful IP address 193.168.80.10. Define the class of address and justify your answer.Range 192 -223 in first octet , therefore class C
- 3Determine and state the default subnet mask for the address 193.168.80.10255.255.255.0 or Binary equivalent 11111111.11111111.11111111.00000000
- 4Calculate the last usable address assuming a default subnet mask.d) 193.168.80.254 (All 1’s in the host portion except the LSB)
- 5Fully summarise the IP addresses 192.16.70.0/25 and 192.16.70.128/25The summary result represent all the bits common to both addresses i.e. 192.16.70.0/24
- 6Name four types of Interior Gateway Distance Vector routing protocolsRIPv1 RIPv2 ,IGRP or EIGRP
- 7b) Identify the metric used for the protocols named in the last card (rip etc)b) Hop count for (RIPv1 and v2), Cost for OSPF that is inversely proportional to Bandwidth and Cost (Includes Bandwidth and Delay) for IGRP and EIGRP.
- 8c) Name two types of loop prevention mechanisms that can be employed by the Distance Vector routing protocols in the previous cards (rip etc)Hold-down timer, Split Horizon, Route Poisoning, Maximum hop count
Hold-down timers prevent a router accepting any changes to a route for a specified period of time. Allows routing updates to propagate through network with the most current information.
The Split Horizon Rule is used to prevent routing loops
Split Horizon rule. A router should not advertise a network through the interface from which the update came. - 9Name four different types of static routesStandard static route, Default static route, Floating static route and Summary static route.
- 10Look up the definition of Administrative distance on the Cisco curriculum.Administrative distance is the feature that routers use in order to select the best path when there are two or more different routes to the same destination from two different routing protocols. Administrative distance defines the reliability of a routing protocol
- 11Zinin’s three Routing principle 1Principle 1: "Every router makes its decision alone, based on the information it has in its own routing table.“
- 12Zinin’s three Routing principle 2"The fact that one router has certain information in its routing table does not mean that other routers have the same information.“
- 13Zinin’s three Routing principle 3Principle 3: "Routing information about a path from one network to another does not provide routing information about the reverse, or return path."
- 14Identify and explain several roles of a router.Best Path determination . Dispatch packets to their destination
Dynamically share routing information between routers.
-Automatically update routing table when topology changes.
Passing Packets between interfaces – Switching - 15Name two methods of implementing Inter VLAN routingc) Per interface Inter-VLAN routing (legacy)
Routing on a stick using subinterfaces
VLAN interface routing used with layer 3 switches - 16a) Name five different metrics used in Dynamic Routing protocolsa) Bandwidth, Delay, Load, Cost, Hop count, Reliability
Bandwidth – The speed of the link in bit/second
Delay is the defined as the measure of time it takes for a packet to traverse a route or the delay introduce by an interface, units are microseconds
Load- A number that reflects how much traffic is using a link
Cost- A composite metric for EIGRP or inversely proportional to Bandwidth for OSPF
Hop Count – The number of routers to a destination
Reliability -A measure of the likelihood that a link will fail - 17Using an example, briefly explain how Routers use routing metricsTo determine to best path to a destination often based upon some least cost criterion.
Metric is a value used by a routing protocol to determine which routes are better than others e.g. a route to a destination with a metric Hop count of 6 is better than an alternative route to the same destination if that alternative route has a metric Hop–count of 10 - 18Name and briefly explain the operation of an Interior Gateway Link State Routing protocolOpen Shortest Path First (OSPF) and Intermediate System –Intermediate system (IS-IS) (4 marks each) Also known as shortest path first algorithms -These protocols built around Dijkstra’s SPF -
Each routers learns about its own directly connected networks
-Link state routers exchange hello packet to “meet” other directly connected link state routers. -Each router builds its own Link State Packet (LSP) which includes information about neighbors such as neighbor ID, link type, & bandwidth. -After the LSP is created the router floods it to all neighbors who then store the information and then forward it until all routers have the same information. -Once all the routers have received all the LSPs, the routers then construct a topological map of - 19b) Name and briefly explain the operation of an Interior Gateway Distance Vector Routing protocolb) RIPv1, RIPv2 ,IGRP or EIGRP(4 marks each) A router using distance vector routing protocols knows 2 things: …………………………………………………………………………………………………………………………………………… * Distance to final destination …………………………………………………………………………………………………………………………………………… Vector or direction traffic should be directed Characteristics of Distance Vector routing protocols: …………………………………………………………………………………………………………………………………………… Periodic updates * Neighbors …………………………………………………………………………………………………………………………………………… * Broadcast updates
- 20b) Explain clearly the purpose of metrics in relation to IP routing protocolsb) To determine the best path or route to a destination Metric is a value used by a routing protocol to determine which routes are better than others e.g. a route to a destination with a metric Hop count of 6 is better than an alternative route to the same destination if that alternative route has a metric Hop–count of 10 (10 marks)
- 21State five general hardware components of a RouterRandom Access Memory -RAM
Read Only Memory- ROM,
Non Volatile Random Access Memory –NVRAM,
Central Processing Unit -CPU ,
Flash memory,
Network Interface ports,
Management Ports( Console, Auxiliary) (2 marks each) - 22With reference to a Router explain the operation for each of the components stated in a)RAM - Stores the Running configuration instruction and data needed to be executed by the CPU
ROM - Stores Bootstrap, Scaled down IOS and basic diagnostic software
NVRAM – Stores the Router Start up configuration files
CPU – Executes operating system instructions
Flash memory- Stores IOS
network Interface ports – Data and protocol carrying ports Management
Ports – To Configure and Manage the Router - 23State clearly how many bits are used in the IPv4 address space32 bits
- 24IPv6 addresses are 128-bit hexadecimal numbersIPv6 addresses are 128-bit hexadecimal numbers
- 25Q2. a) Explain the basic hardware components of a routerRandom Access Memory –RAM volatile, Read Only Memory- ROM, Non Volatile Random Access Memory –NVRAM, Central Processing Unit -CPU , Flash memory non volatile, Network Interface ports (Ethernet, Serial), Management Ports( Console, Auxiliary, VTY)
- 26b) Explain how a Router uses the components described in a)RAM - Stores the Running configuration instruction and data needed to be executed by the CPU
ROM - Stores Bootstrap, Scaled down IOS and basic diagnostic software
NVRAM – Stores the Router Start up configuration files
CPU – Executes operating system instructions
Flash memory- Stores IOS
Network Interface ports – Data and protocol carrying ports
Management Ports – To Configure and Manage the Router - 27c) Describe the router boot sequencePerform a Power On Self Test (POST) from ROM
Execute the Bootstrap Loader from ROM
Locate the Internetwork Operating System IOS from Flash or TFTP server
Load the IOS
Locate the configuration file from NVRAM, TFTP or enter the console setup mode
Execute the configuration file in RAM - 28Q4. a) Explain three advantages of implementing Dynamic routing protocols in a network.Automatically adaptable to network changes, Improved scalability with network growth, network changes can be quickly disseminated. Some can guarantee a loop free topology
- 29b) Describe a possible security vulnerability of using Dynamic routing protocolsRouting updates may be from an authenticated source. Routing updates may be advertised to unauthenticated parties. Unencrypted updates may be captured and modified by unauthenticated parties
- 30Q5. a) Describe the purpose of metrics in relation to Distance Vector and Link State IP routing protocols.(Answers may vary but should include distance vector and link state examples) To determine the best path or route to a destination Metric is a value used by a routing protocol to determine which routes are better than others e.g. a route to a destination with a metric Hop count of 6 is better than an alternative route to the same destination if that alternative route has a metric Hop–count of 10 Equally a route learnt via EIGRP with a metric of 30720 to a destination is better a route to the same destination with a metric of 33280
- 31b) Identify the routing protocol that uses the formula below: metric = 256 *{107/minimum(bandwidth) + ∑ delays/10EIGRP
- 32c) Describe typical values for the variables in the formula.For FastEthernet Bandwidth 100000 Kb/s 100µs For Ethernet Bandwidth 10000 Kb/s 1000µs For Serial Bandwidth 1544 Kb/s 20000µs
- 33i. The Protocol Data Units (PDU’s) for layers 4,3,2 and 1 ( in relation to osi model)PDU Segments, Packets or Datagrams, Frames and bits respectively
- 34ii. The bit length of the addressing at layers 3 and 232 bits for Packet or Datagrams, 48 bits for Frames
- 35e) A web server runs on a computer with the domain name eagle-serve.example.com. A browser accesses a page with a URL of http://eagle-server.example.com/index.html. The browser host, DNS host and web server host are connected to the same Ethernet LAN segment. Give an account of the events that take place as the browser requests the page. Relate your account to protocols described in any relevant layers of the OSI model. Assume all caches are emptyA host start the browser and enters the URL into the browser address box The Browser application formulates a DNS request. The DNS server responds with the IP address of the Web server. The Browser initiates a 3 way handshake with the Web server to establish a reliable TCP communication channel between the host and server. The Bowser application layer formulates a HTTP GET request to the server. The request is encapsulated in a TCP segment at the Transport layer with a randomly assigned source port and a well known destination port of 80, the segment is then passed down to the Network layer. At the Network layer the segment is encapsulated into a packet with the source address of the host and destination IP address of the server. The destination IP address of the server is a response to a DNS request to convert the domain name of the requested page into an IP address. An ARP request is formulated to map the destination IP address to the destination MAC address. This desination MAC address is passed to the Datalink layer At the Datalink layer the Packet is encapsulated into a Frame. T
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- Karteikarten am Ohne Titel, erstellt von Saunders Dan am 15/03/2015.
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