Project Report Networking

1. Networks and Devices 1.1 Introduction In one network more than one computer connected with each other through centralized device. They can share files and resources with each other. 1.2 Types of networks: 1.2.1 Personal area network A personal area network (PAN) is a computer network used for communication among computer and different information technological devices close to one person. Some examples of devices that are used in a PAN are personal computers, printers, fax machines, telephones, PDAs, scanners, and even video game consoles. A PAN may include wired and wireless connections between devices. The reach of a PAN typically extends to 10 meters. A wired PAN is usually constructed with USB and Firewire connections while technologies such as Bluetooth and infrared communication typically form a wireless PAN 1.2.2 Local area network A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings. Each computer or device on the network is a node. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-T G.hn also provide a way to create a wired LAN using existing home wires The defining characteristics of LANs, in contrast to WANs (Wide Area Networks), include their higher data transfer rates, smaller geographic range, and no need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 40 and 100 Gbit/s. 1.2.3 Wide area network A wide area network (WAN) is a computer network that covers a large geographic area such as a city, country, or spans even intercontinental distances, using a communications channel that combines many types of media such as telephone lines, cables, and air waves. A WAN often uses transmission facilities provided by common carriers, such as telephone companies. 1

WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer. A virtual private network (VPN) is a computer network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires. The data link layer protocols of the virtual network are said to be tunneled through the larger network when this is the case. One common application is secure communications through the public Internet, but a VPN need not have explicit security features, such as authentication or content encryption. VPNs, for example, can be used to separate the traffic of different user communities over an underlying network with strong security features. A VPN may have best-effort performance, or may have a defined service level agreement (SLA) between the VPN customer and the VPN service provider. Generally, a VPN has a topology more complex than point-to-point. 1.3 Cabling Several physical data-transmission media are available to connect together the various devices on a network. One possibility is to use cables. There are many types of cables, but the most common are: Coaxial cable 1.3.1 Coaxial cable A coaxial cable is made of up a central copper wire (called a core) surrounded by an insulator, and then a braided metal shield. Twisted pair cable

Figure 1.1 : Structure of coaxial cable

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The jacket protects the cable from the external environment. It is usually made of rubber (or sometimes Polyvinyl Chloride (PVC) or Teflon). The shield (metal envelope) surrounding the cables protects the data transmitted on the medium from interference (also called noise) that could corrupt the data. The insulator surrounding the central core is made of a dielectric material that prevents any contact with the shield that could cause electrical interactions (short circuit).

1.3.2 Twisted pair cable In its simplest form, twisted-pair cable consists of two copper strands woven into a braid and covered with insulation.Two types of twisted pair cable are generally recognized: Unshielded Twisted Pair (UTP) Shielded Twisted-Pair (STP)

A cable is often made of several twisted pairs grouped together inside a protective jacket. The twisting eliminates noise (electrical interference) due to adjacent pairs or other sources (motors, relays, transformers). Twisted pair is therefore suitable for a local network with few nodes, a limited budget and simple connectivity. However, over long distances at high data rates it does not guarantee data integrity (i.e. loss-less data transmission). 1.3.2.1 Unshielded Twisted Pair (UTP) UTP cable complies with the 10BaseT specification. This is the most commonly used twisted pair type and the most widely used on local networks. Here are some of its characteristics:

Maximum segment length: 100 metres Composition: 2 copper wires covered with insulation UTP Standards: determine the number of twists per foot (33 cm) of cable depending on the intended use.

Most telephone installations use UTP cable. Many buildings are pre-wired for this type of installation (often in sufficient number to satisfy future requirements). If the pre-installed 3

twisted pair is of good quality, it can be used to transfer data in a computer network. Attention must be paid, however, to the number of twists and other electrical characteristics required for quality data transmission. 1.3.2.2 Shielded Twisted Pair (STP) STP (Shielded Twisted Pair) cable uses a copper jacket that is of better quality and more protective that the jacket used for UTP cable. It contains a protective envelope between the pairs and around the pairs. In an STP cable, the copper wires of one pair are themselves twisted, which provides STP cable with excellent shielding, (in other words, better protection against interference). It also allows faster transmission over a longer distance. 1.4 Hub An Ethernet hub, active hub, network hub, repeater hub, hub or concentrator is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and making them act as a single network segment. Hubs work at the physical layer (layer 1) of the OSI model. The device is a form of multiport repeater. Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision. Hubs also often come with a BNC and/or AUI connector to allow connection to legacy 10BASE2 or 10BASE5 network segments. A network hub is a fairly unsophisticated broadcast device. Hubs do not manage any of the traffic that comes through them, and any packet entering any port is broadcast out on all other ports. Since every packet is being sent out through all other ports, packet collisions resultwhich greatly impedes the smooth flow of traffic.

Figure 1.2: Basic Topology of Hub Most hubs detect typical problems, such as excessive collisions and jabbering on individual ports, and partition the port, disconnecting it from the shared medium. Thus, hub-based 4

Ethernet is generally more robust than coaxial cable-based Ethernet (e.g. 10BASE2, thinnet), where a misbehaving device can adversely affect the entire collision domain. Hubs are classified as Layer 1 (Physical Layer) devices in the OSI model. At the physical layer, hubs support little in the way of sophisticated networking. Hubs do not read any of the data passing through them and are not aware of their source or destination. Essentially, a hub simply receives incoming packets, regenerates the electrical signal, and broadcasts these packets out to all other devices on the network. Uses: For inserting a protocol analyzer into a network connection, a hub is an alternative to

a network tap or port mirroring. Some computer clusters require each member computer to receive all of the traffic

going to the cluster. A hub will do this naturally; using a switch requires special configuration. 1.5 Switch A network switch or switching hub is a computer networking device that connects network segments. The term commonly refers to a network bridge that processes and routes data at the data link layer (layer 2) of the OSI model. Switches that additionally process data at the network layer (layer 3 and above) are often referred to as Layer 3 switches or multilayer switches. The term network switch does not generally encompass unintelligent or passive network devices such as hubs and repeaters. 1.5.1 Functions The network switch, packet switch (or just switch) plays an integral part in most Ethernet local area networks or LANs. Small office/home office (SOHO) applications typically use a single switch, or an all-purpose converged device such as a gateway access to small office/home broadband services such as DSL router or cable Wi-Fi router. In most of these

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cases, the end-user device contains a router and components that interface to the particular physical broadband technology, as in Linksys 8-port and 48-port devices.

Figure 1.3: Switch used in a network A standard 10/100 Ethernet switch operates at the data-link layer of the OSI model to create a different collision domain for each switch port. If you have 4 computers (e.g., A, B, C, and D) on 4 switch ports, then A and B can transfer data back and forth, while C and D also do so simultaneously, and the two "conversations" will not interfere with one another. In the case of a "hub," they would all share the bandwidth and run in Half duplex, resulting in collisions, which would then necessitate retransmissions. Using a switch is called microsegmentation. This allows you to have dedicated bandwidth on point-to-point connections with every computer and to therefore run in Full duplex with no collisions. 1.5.2 Role of switches in networks Switches may operate at one or more OSI layers, including physical, data link, network, or transport (i.e., end-to-end). A device that operates simultaneously at more than one of these layers is known as a multilayer switch. In switches intended for commercial use, built-in or modular interfaces make it possible to connect different types of networks, including Ethernet, Fibre Channel, ATM, ITU-T G.hn and 802.11. This connectivity can be at any of the layers mentioned. While Layer 2 functionality is adequate for bandwidth-shifting within one technology, interconnecting technologies such as Ethernet and token ring are easier at Layer 3. 6

Interconnection of different Layer 3 networks is done by routers. If there are any features that characterize "Layer-3 switches" as opposed to general-purpose routers, it tends to be that they are optimized, in larger switches, for high-density Ethernet connectivity. 1.6 Routers A router is a device that interconnects two or more computer networks, and selectively interchanges packets of data between them. Each data packet contains address information that a router can use to determine if the source and destination are on the same network, or if the data packet must be transferred from one network to another. Where multiple routers are used in a large collection of interconnected networks, the routers exchange information about target system addresses, so that each router can build up a table showing the preferred paths between any two systems on the interconnected networks. A router is a networking device whose software and hardware are customized to the tasks of routing and forwarding information. A router has two or more network interfaces, which may be to different physical types of network (such as copper cables, fiber, or wireless) or different network standards. There are two types of routers: (i) Hardware Routers are developed by Cisco, HP. (ii) Software Routers is configured with the help of routing and remote access. This feature is offered by Microsoft. This feature is by default installed, but you have to enable or configure it. Hardware routers are dedicated routers. They are more efficient. Routers connect two or more logical subnets, which do not share a common network address. The subnets in the router do not necessarily map one-to-one to the physical interfaces of the router. The term "layer 3 switching" is used often interchangeably with the term "routing". The term switching is generally used to refer to data forwarding between two network devices that share a common network address. This is also called layer 2 switching or LAN switching. Conceptually, a router operates in two operational planes (or sub-systems).

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Control plane: where a router builds a table (called routing table) as how a packet should be forwarded through which interface, by using either statically configured statements (called static routes) or by exchanging information with other routers in the network through a dynamical routing protocol;

Forwarding plane: where the router actually forwards traffic (called packets in IP) from ingress (incoming) interfaces to an egress (outgoing) interface that is appropriate for the destination address that the packet carries with it.

1.7 Bridge Bridge is a hardware device, which is used to provide LAN segmentation means it is used for break the collision domain. It has same functionality as performed by switch. We can use bridge between two different topologies. It has fewer ports. Each port has a own buffer memory. It works on Data Link Layer of OSI model. It also read mac address and stores it in its filter table. In case of bridge there is one broadcast domain.

2. IP Addressing and Subnetting 8

2.1 IP Address An Internet Protocol address (IP address) is a numerical label that is assigned to devices participating in a computer network that uses the Internet Protocol for communication between its nodes. An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there." The designers of TCP/IP defined an IP address as a 32-bit number and this system, known as Internet Protocol Version 4 or IPv4, is still in use today. However, due to the enormous growth of the Internet and the predicted depletion of available addresses, a new addressing system (IPv6), using 128 bits for the address, was developed in 1995 and standardized by RFC 2460 in 1998. Although IP addresses are stored as binary numbers, they are usually displayed in human-readable notations, such as 208.77.188.166 (for IPv4), and 2001:db8:0:1234:0:567:1:1 (for IPv6). The Internet Protocol is used to route data packets between networks; IP addresses specify the locations of the source and destination nodes in the topology of the routing system. For this purpose, some of the bits in an IP address are used to designate a subnetwork. The number of these bits is indicated in CIDR notation, appended to the IP address; e.g., 208.77.188.166/24. As the development of private networks raised the threat of IPv4 address exhaustion, RFC 1918 set aside a group of private address spaces that may be used by anyone on private networks. They are often used with network address translators to connect to the global public Internet. The Internet Assigned Numbers Authority (IANA), which manages the IP address space allocations globally, cooperates with five Regional Internet Registries (RIRs) to allocate IP address blocks to Local Internet Registries (Internet service providers) and other entities.

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2.2 IP versions Two versions of the Internet Protocol (IP) are in use: IP Version 4 and IP Version 6. Each version defines an IP address differently. Because of its prevalence, the generic term IP address typically still refers to the addresses defined by IPv4. 2.2.1 IP version 4 addresses IPv4 uses 32-bit (4-byte) addresses, which limits the address space to 4,294,967,296 (232) possible unique addresses. IPv4 reserves some addresses for special purposes such as private networks (~18 million addresses) or multicast addresses (~270 million addresses).

Figure 2.1: An IPv4 Address IPv4 addresses are usually represented in dot-decimal notation (four numbers, each ranging from 0 to 255, separated by dots, e.g. 208.77.188.166). Each part represents 8 bits of the address, and is therefore called an octet. In less common cases of technical writing, IPv4 addresses may be presented in hexadecimal, octal, or binary representations. In most representations each octet is converted individually. 2.2.1.1 IPv4 subnetting In the early stages of development of the Internet Protocol, network administrators interpreted an IP address in two parts, network number portion and host number portion. The highest order octet (most significant eight bits) in an address was designated as the network number and the rest of the bits were called the rest field or host identifier and were used for host numbering within a network.

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Classful network design allowed for a larger number of individual network assignments and fine-grained subnetwork design. The first three bits of the most significant octet of an IP address was defined as the class of the address. Three classes (A, B, and C) were defined for universal unicast addressing. Depending on the class derived, the network identification was based on octet boundary segments of the entire address. Each class used successively additional octets in the network identifier, thus reducing the possible number of hosts in the higher order classes (B and C). The following table gives an overview of this now obsolete system. Table 2.1: Historical classful network architecture : Range of first Network Host Number of Number octet 0 - 127 128 - 191 192 - 223 ID a a.b a.b.c ID networks addresses 224-2

Class A B C

first octet in binary 0XXXXXXX 10XXXXXX 110XXXXX

of =

b.c.d 27 = 128 c.d d14

16,777,214 2 = 16,384 216-2 = 65,534 221 = 2,097,152 28-2 = 254

Although classful network design was a successful developmental stage, it proved unscalable in the face of the rapid expansion of the Internet, and in the mid 1990s it started to become abandoned because of the introduction of Classless Inter-Domain Routing (CIDR) for the allocation of IP address blocks and new rules for routing IPv4 packets. CIDR is based on variable-length subnet masking (VLSM) to allow allocation and routing based on arbitrarylength prefixes. Today, remnants of classful network concepts function only in a limited scope as the default configuration parameters of some network software and hardware components (e.g. netmask), and in the technical jargon used in network administrators' discussions. 2.2.1.2 IPv4 private addresses Early network design, when global end-to-end connectivity was envisioned for communications with all Internet hosts, intended that IP addresses be uniquely assigned to a particular computer or device. However, it was found that this was not always necessary as private networks developed and public address space needed to be conserved. IANA-reserved private IPv4 network ranges Start

End

No. of addresses 11

24-bit Block (/8 prefix, 1 x A) 10.0.0.0 10.255.255.255 16,777,216 20-bit Block (/12 prefix, 16 x B) 172.16.0.0 172.31.255.255 1,048,576 16-bit Block (/16 prefix, 256 x C) 192.168.0.0 192.168.255.255 65,536 Any user may use any of the reserved blocks. Typically, a network administrator will divide a block into subnets; for example, many home routers automatically use a default address range of 192.168.0.0 - 192.168.0.255 (192.168.0.0/24).

2.2.2 IP version 6 addresses

Figure 2.2: Illustration of an IP address (version 6), in hexadecimal and binary The rapid exhaustion of IPv4 address space, despite conservation techniques, prompted the Internet Engineering Task Force (IETF) to explore new technologies to expand the Internet's addressing capability. The permanent solution was deemed to be a redesign of the Internet Protocol itself. This next generation of the Internet Protocol, aimed to replace IPv4 on the Internet, was eventually named Internet Protocol Version 6 (IPv6) in 1995 The address size was increased from 32 to 128 bits or 16 octets, which, even with a generous assignment of network blocks, is deemed sufficient for the foreseeable future. Mathematically, the new address space provides the potential for a maximum of 2128, or about 3.403 1038 unique addresses. The new design is not based on the goal to provide a sufficient quantity of addresses alone, but rather to allow efficient aggregation of subnet routing prefixes to occur at routing nodes. As a result, routing table sizes are smaller, and the smallest possible individual allocation is a subnet for 264 hosts, which is the square of the size of the entire IPv4 Internet. At these levels, actual address utilization rates will be small on any IPv6 network segment. The new design also provides the opportunity to separate the addressing infrastructure of a network segment 12

that is the local administration of the segment's available spacefrom the addressing prefix used to route external traffic for a network. IPv6 has facilities that automatically change the routing prefix of entire networks should the global connectivity or the routing policy change without requiring internal redesign or renumbering. The large number of IPv6 addresses allows large blocks to be assigned for specific purposes and, where appropriate, to be aggregated for efficient routing. With a large address space, there is not the need to have complex address conservation methods as used in Classless Inter-Domain Routing (CIDR). All modern desktop and enterprise server operating systems include native support for the IPv6 protocol, but it is not yet widely deployed in other devices, such as home networking routers, voice over Internet Protocol (VoIP) and multimedia equipment, and network peripherals. 2.3 Subnet A subnetwork, or subnet, is a logically visible, distinctly addressed part of a single Internet Protocol network. The process of subnetting is the division of a computer network into groups of computers that have a common, designated IP address routing prefix. Subnetting breaks a network into smaller realms that may use existing address space more efficiently, and, when physically separated, may prevent excessive rates of Ethernet packet collision in a larger network. The subnets may be arranged logically in a hierarchical architecture, partitioning the organization's network address space into a tree-like routing structure. Routers are used to interchange traffic between subnetworks and constitute logical or physical borders between the subnets. They manage traffic between subnets based on the high-order bit sequence (routing prefix) of the addresses. A routing prefix is the sequence of leading (most-significant) bits of an IP address that precede both the portion of the address used as host identifier and, if applicable, the set of bits that designate the subnet number. Routing prefixes are expressed in CIDR notation, which uses the first address of a network followed by the bit-length of the prefix, separated by a slash (/) character. For example, 192.168.1.0/24 is the prefix of the IPv4 network starting at the given address, having 24 bits allocated for the network number, and the rest (8 13

bits) reserved for host addressing. The IPv6 address specification 2001:db8::/32 is a large network for 296 hosts, having a 32-bit routing prefix. In IPv4 networks, the routing prefix is traditionally expressed as a subnet mask, which is the prefix bit mask expressed in quad-dotted decimal representation. For example, 255.255.255.0 is the subnet mask for the 192.168.1.0/24 prefix. All hosts within a subnet can be reached in one routing hop, implying that all hosts in a subnet are connected to the same link. A typical subnet is a physical network served by one router, for instance an Ethernet network, possibly consisting of one or several Ethernet segments or local area networks, interconnected by network switches and network bridges or a Virtual Local Area Network (VLAN). However, subnetting allows the network to be logically divided regardless of the physical layout of a network, since it is possible to divide a physical network into several subnets by configuring different host computers to use different routers. While improving network performance, subnetting increases routing complexity, since each locally connected subnet must be represented by a separate entry in the routing tables of each connected router. However, by careful design of the network, routes to collections of more distant subnets within the branches of a tree-hierarchy can be aggregated by single routes. Existing subnetting functionality in routers made the introduction of Classless Inter-Domain Routing seamless. 2.4 Subnetting 2.4.1 Network addressing Computers and devices that are participating in a network such as the Internet each have a logical address. Usually this address is unique to each device and can either be configured dynamically from a network server or statically by an administrator. An address fulfills the functions of identifying the host and locating it on the network. It allows a device to communicate with other devices connected to the network. The most common network addressing architecture is Internet Protocol version 4 (IPv4), but its successor, IPv6 is in early deployment stages. An IPv4 address consists of 32 bits, for human readability written in a form consisting of four decimal octets separated by full stops (dots), called dot-decimal 14

notation. An IPv6 address consists of 128 bits written in a hexadecimal notation and grouping 16 bits separated by colons. In order to facilitate routing a data packet across multiple networks, the address is divided into two parts:

Network prefix: A contiguous group of high-order bits that are common among all hosts within a network. Host identifier: The remaining low-order bits of the address that are not designated in the network prefix. This part specifies a particular device in the local network.

The network prefix may be written in a form identical to that of the address itself. In IPv4, this is called the subnet mask of the address. For example, a specification of the mostsignificant 18 bits of an address, 11111111.11111111.11000000.00000000, is written as 255.255.192.0. The modern standard form of specification of the routing prefix counts the number of bits in the routing prefix and appends that number to the address with a slash (/) separator:

192.168.0.0, netmask 255.255.0.0 192.168.0.0/16

This latter notation is used preferentially in Classless Inter-Domain Routing and is called CIDR notation. In IPv6 this is the only acceptable form to denote routing prefixes. 2.4.2 The subnetting operation The process of subnetting involves the separation of the network and subnet portion of an address from the host identifier. This is performed by a bitwise AND operation between the IP address and the subnet prefix or bit mask. The result yields the network address, and the remainder is the host identifier. The following example is based on IPv4 networking. The operation may be visualized in a table using binary address formats. Dot-decimal notation Binary form 192.168.5.130 11000000.10101000.00000101.10000010 15

IP address

Subnet Mask 255.255.255.0 Network Portion 192.168.5.0 Host Portion 0.0.0.130

11111111.11111111.11111111.00000000 11000000.10101000.00000101.00000000 00000000.00000000.00000000.10000010

In IPv4, subnet masks consist of 32 bits, usually a sequence of ones (1) followed by a block of 0s. The last block of zeros (0) designate that part as being the host identifier. Subnetting is the process of designating bits from the host portion and grouping them with the network portion. This divides a network into smaller subnets. The following diagram modifies the example by moving two bits from the host portion to the subnet number to form a smaller subnet: Dot-decimal notation 192.168.5.130 255.255.255.192 192.168.5.128 0.0.0.2 Binary form 11000000.10101000.00000101.10000010 11111111.11111111.11111111.11000000 11000000.10101000.00000101.10000000 00000000.00000000.00000000.00000010

IP address Subnet Mask Network Portion Host Portion

2.5 MAC Address In computer networking, a Media Access Control address (MAC address) is a unique identifier assigned to network adapters or network interface cards (NICs) usually by the manufacturer for identification. If assigned by the manufacturer, a MAC address usually encodes the manufacturer's registered identification number. It may also be known as an Ethernet Hardware Address (EHA), hardware address, adapter address, or physical address. MAC addresses are used in the Media Access Control protocol sub-layer of the OSI reference model. There are three numbering spaces, managed by the Institute of Electrical and Electronics Engineers (IEEE), which are in common use for formulating a MAC address: MAC-48, EUI48, and EUI-64. The IEEE claims trademarks on the names "EUI-48" and "EUI-64", where "EUI" stands for Extended Unique Identifier. Although intended to be a permanent and globally unique identification, it is possible to change the MAC address on most of today's hardware, an action often referred to as MAC spoofing. Unlike IP address spoofing, where a sender spoofing their address in a request tricks the other party into sending the response elsewhere, in MAC address spoofing, the

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response is received by the spoofing party. However, MAC address spoofing is limited to the local broadcast domain. A host cannot determine from the MAC address of another host whether that host is on the same link (network segment) as the sending host, or on a network segment bridged to that network segment. In TCP/IP networks, the MAC address of a subnet interface can be queried knowing the IP address (equivalent to OSI Layer 3) using the Address Resolution Protocol (ARP) for Internet Protocol Version 4 (IPv4) or the Neighbor Discovery Protocol (NDP) for IPv6. On broadcast networks, such as Ethernet, the MAC address uniquely identifies each node on that segment and allows frames to be marked for specific hosts. It thus forms the basis of most of the Link layer (OSI Layer 2) networking upon which upper layer protocols rely to produce complex, functioning networks.

3.Routing and Routing Protocols 3.1 Routing o The term routing is used for taking a packet from one device and sending it through the network to another device on a different network. o Routers dont really care about hoststhey only care about networks and the best path to each network. Routers route traffic to all the networks in your internetwork. To be able to route packets, a router must know, at a minimum, the following: Destination address 17

Neighbor routers from which it can learn about remote networks Possible routes to all remote networks The best route to each remote network How to maintain and verify routing information

192.168.10.1 F 0/0

192.168.20.1 F 0/0

192.168.10.2 Internet

192.168.20.2

Figure 3.1: Routing Routing is taking place from Host_A to Host_B through the Lab_A Router. To be able to route, the router must know how to get into the network 172.16.20.0

3.2 Routing Types 3.2.1. Static Routing 3.2.2. Default Routing 3.2.3. Dynamic Routing 3.2.1 Static Routing Static routing occurs when you manually add routes in each routers routing table. By default, Static routes have an Administrative Distance (AD) of 1 Features: There is no overhead on the router CPU There is no bandwidth usage between routers It adds security, because the administrator can choose to allow routing access to certain networks only. Configuration Static Routing Router (config)#ip route Destination_network Mask Next-Hop_Address (or) 18

Router (config)#ip route Destination_network Mask Exit interface ip route : The command used to create the static route. destination_network : The network youre placing in the routing table. mask : The subnet mask being used on the network. next-hop_address : The address of the next-hop router Exitinterface : You can use it in place of the next-hop address administrative_distance : By default, static routes have an administrative distance of 1

DTE F0/0 S0/0

DCE

DTE

DCE F0/0

S0/0

S0/1

S0/0

DTE - Data Terminal Equipment DCE - Data Communication Equipment

Figure 3.2: Static Routing Configuraion 3.2.2 Default Routing

Default routing is used to send packets with a remote destination network not In the routing table to the next-hop router. We can only use default routing on stup networks. Those with only one exit Path out of the network. Configuration Default Routing Router(config)#ip route 0.0.0.0 0.0.0.0 Next-Hop_Address Router(config)#ip route 0.0.0.0 0.0.0.0 Exit interface Router(config)#ip default-network ? 3.2.3 Dynamic Routing

Dynamic routing is when protocols are used to find networks and update routing table on routers. A routing protocol defines the set of rules used by router when it communicates routing information between neighbor routers There are two type of routing protocols used in internetwors: 19

Interior Gateway Protocols (IGPs) IGPs are used to exchange routing information with routers in the same Autonomous System(AS) number. Exterior Gateway Protocols (EGPs) EGPs are used to communicate between different Autonomous System.

Autonomous System An autonomous system is a collection of networks under a common administrative domain, which basically means that all routers sharing the same routing table information are in the same AS. 3.3 Routing Protocol Basics 3.3.1 Administrative Distances 3.3.2 Routing protocol 3.3.1 Administrative Distances The Administrative Distance (AD) is used to rate the trustworthiness of routing information received on a router from a neighbor router. An Administrative Distance is an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be passed via this route. If a router receives two updates listing he sane remote network, the first thing the router checks is the AD. If one of the advertised routes has lower AD than the other, then the route with the lowest AD will be placed in the routing table. If both advertised routes to the same network have the same AD, then routing protocol metrics (such as hop count or bandwidth of the lines) will be used to find the best path to the remote network. The advertised route with the lowest metric will be placed in the routing table. But if both advertised routes have the same AD as well as the same metrics, then the routing protocol will load-balance in the remote network 3.3.2 Routing protocols There are three classes of routing protocols: 3.3.2.1 Distance vector protocol 3.3.2.2 Link state protocol 20

3.3.2.3 Hybrid protocol 3.3.2.1 Distance vector protocol The Distance-vector protocols find the best path to remote network by judging distance. Each time a packet goes through a router, thats called a hop. The route with the least number of hops to the network is determined to be the best route. The vector indicates the direction to the remote network. They send the entire routing table to directly connected neighbors. Ex: RIP, IGRP. 3.3.2.2 Link state protocol Also called shortest-path-first protocols, the routers each create three separate tables. One keeps track of directly attached neighbors, one determines the topology of the entire internet work, and one is used as the routing tables. Link state routers know more about the internet work than any distance-vector routing protocol. Link state protocols send updates containing the state of their own links to all other routers on the network . Ex: OSPF 3.3.2.3 Hybrid protocol Hybrid protocol use aspects of both distance-vector and link state protocol. Ex: EIGRP 3.4 Routing Information Protocol (RIP) Routing Information Protocol is a true distance-vector routing protocol. It sends the complete routing table out to all active interfaces every 30 seconds. RIP only uses hop count to determine the best way to remote network, but it has a maximum allowable hop count of 0-15 by default, meaning that 16 is deemed unreachable. RIP version 1 uses only class full routing, which means that all devices in the network must use the same subnet mask. RIP version 2 provides something called prefix routing, and does send subnet mask information with the route updates. This is called classless routing. Comparison of RIPv1 And RIPv2 :-

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Both RIPv1 and RIPv2 are distance-vector protocols, which mean that each router running RIP sends its complete routing tables out all active interfaces at periodic time intervals.

The timers and loop-avoidance schemes are the same in both RIP versions. Both RIPv1 and RIPv2 are configured as classful addressing, (but RIPv2 is considered classless because subnet information is sent with each route update) Both have the same administrative distance (120) RIP is an open standard, you can use RIP with any brand of router. Alogrithm Bellman Ford Multicast address 224.0.0.9

Table 3.1 : Comparison of RIPv1 And RIPv2 RIP Version 1 Distance Vector Maximum hop count of 15 Classful No support for VLSM No support for discontiguous RIP Version 2 Distance Vector Maximum hop count of 15 Classless Supports VLSM networks Support discontiguous networks

3.5 Interior Gateway Routing Protocol (IGRP) Interior Gateway Routing Protocol (IGRP) is a Cisco-proprietary distance-vector routing protocol. To use IGRP, all your routers must be Cisco routers. IGRP has a maximum hop count of 255 with a default of 100. IGRP uses bandwidth and delay of the line by default as a metric for determining the best route to an internetwork.

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Reliability, load, and maximum transmission unit (MTU) can also be used, although they are not used by default. Note: The main difference between RIP and IGRP configuration is that when you configure IGRP, you supply the autonomous system number. All routers must use the same number in order to share routing table information. Table 3.2: Difference between IGRP And RIP IGRP Can be used in large internetworks RIP Works best in smaller networks

Uses an autonomous system number for Does not yse aytibiniys system numbers activation Gives a full route table update every 90 Gives full route table update every 30 seconds Has an administrative distance of 100 seconds Has an administrative distance of 120

Uses bandwidth and delay of the line as Uses only hop count to determine the best metric (lowest composite metric),with a path to a remote network, with 15 hops maximum hop count of 255 being the maximum

3.6 EIGRP (Enhanced Interior Gateway Routing Protocol) o Enhanced IGRP (EIGRP) is a classless, enhanced distance-vector protocol that gives us a real edge over IGRP. o Like IGRP, EIGRP uses the concept of an autonomous system to describe the set of contiguous routers that run the same routing protocol and share routing information. o But unlike IGRP, EIGRP includes the subnet mask in its route updates o The advertisement of subnet information allows us to use VLSM and Summarization when designing our networks. o EIGRP is sometimes referred to as a hybrid routing protocol because ithas characteristics of both distance-vector and link-state protocols. o It sends traditional distance-vector updates containing information about networks plus the cost of reaching them from the perspective of the adverting router o EIGRP has a maximum hop count of 255.

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Powerful features that make EIGRP a real standout from IGRP : Support for IP, IPX, and AppleTalk via protocol-dependent Support for VLSM/CIDR Support for summaries and discontiguous networks Efficient neighbor discovery Communication via Reliable Transport Protocol (RTP) Best path selection via Diffusing Update Algorithm (DUAL) modules Considered classless (same as RIPv2 and OSP

3.6.1. Routing Table Stores the routes that are currently used to make routing decisions. 3.6.2. Neighbour Table Records information about routers with whom neighborship relationships have been formed. 3.6.3. Topology Table Stores the route advertisements about every route in the internetwork received from each neighbor. 3.6.1 Routing Table List of directly connected routers running EIGRP with which this router has an adjacency IP IGRP Neighbors Table Next-Hop Router Interface

List of all routers learned from Each EIGRP neighbors List of all best routes from EIGRP topology table and other routing processes Feasible distance

IP EIGRP Topology Table Destination 1 FD and AD via each neighbors

Destination

The IP Routing Table Best Route

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This is the best metric along all paths to a remote network, including the metric to the neighbor that is advertising that remote network. This is the route that you will find in the routing table, because it is considered the best path. The metric of a feasible distance is the metric reported by the neighbor (called reported distance), plus the metric to the neighbor reporting the route. Reported distance ( Advertised Distance ) This is the metric of a remote network, as reported by a neighbor. It is also the routing table metric of the neighbor. 3.6.2 Neighbour Table Each router keeps state information about adjacent neighbors. When a newly discovered neighbor is learned, the address and interface of the neighbor are recorded, and this information is held in the neighbor table, stored in RAM. There is one neighbor table for each protocol-dependent module 3.6.3 Topology Table The topology table is populated by the PDMs and acted upon by the Diffusing Update Algorithm (DUAL). It contains all destinations advertised by neighboring routers, holding each destination address and a list of neighbors that have advertised the destination. For each neighbor, the advertised metric is recorded, which comes only from the neighbors routing table. If the neighbor is advertising this destination, it must be using the route to forward packets. 3.7 OSPF (Open Shortest Path First) Open Shortest Path First (OSPF) is an open standards routing protocol thats been implemented by a wide variety of network vendors, including Cisco. This works by using the Dijkstra algorithm. First, a shortest path tree is constructed, and then the routing table is populated with the resulting best paths. OSPF converges quickly, although perhaps not as quickly as EIGRP, and it supports multiple, equal-cost routes to the same destination. But unlike EIGRP, it only supports IP routing.

OSPF provides the following features: 25

Consists of areas and autonomous systems Minimizes routing update traffic Allows scalability Supports VLSM/CIDR Has unlimited hop count Allows multi-vendor deployment (open standard) Table 3.3: OSPF and RIP comparison

Chracteristic Type of protocol Classless support VLSM support Auto summarization Manual summarization Discontiguous Route propagation Path metric Hop count limit Convergence Peer authentication Hierarchical network Updates Event Route computation

OSPF Link-state Yes Yes No Yes Yes Multicast change Bandwidth None Fast Yes Yes (using areas) Triggered Dijkstra

RIPv2 Distance-vector Yes Yes Yes No Yes on Periodic multicast Hops 15 Slow Yes Yes Routetable updates Bellman-Ford

RIPv1 Distance-vector No No Yes No No Periodic multicast Hops 15 Slow No No Routable updates Bell-Ford

OSPF is supposed to be designed in a hierarchical fashion, which basically means that you can separate the larger internetwork into smaller internetworks called areas. This is the best design for OSPF. The reasons for creating OSPF in a hierarchical design include: To decrease routing overhead To speed up convergence To confine network instability to single areas of the network 26

Each router in the network connects to the backbone called area 0, or the backbone area. OSPF must have an area 0, and all routers should connect to this area if at all possible. But routers that connect other areas to the backbone within an AS are called Area Border Routers (ABRs). Still, at least one interface must be in area 0. OSPF runs inside an autonomous system, but can also connect multiple autonomous systems together. The router that connects these ASes together is called an Autonomous System Boundary Router (ASBR).

STUDY AND SIMULATION OF JAMMU & KASHMIR STATE WIDE AREA NETWORK [JKSWAN]

THE PROJECT4.1. Introduction 4.1.1 Jammu & Kashmir State Jammu & Kashmir state has taken a pioneer initiative by adopting the e-Governance in the State. This initiative has been taken by the State to transform itself into a knowledge society. The initiative will include delivery of citizen services through innovative programmes catering both urban as well as rural people. The Government of Jammu & Kashmir, acting 27

through its nodal IT & e-governance department, that is, Information Technology Department, Govt. of J&K, hereinafter, for providing better quality of citizen services to the people of Jammu & Kashmir. Jammu & Kashmir covers 21,01,437 sq. Kms(excluding Pakistan and China occupied parts), with a population of approximately 77,18,700. The State has witnessed rapid expansion of telecom networks both in the public and private sector domains in recent years. The major telecom players in the state today include BSNL, Reliance Infocom, Bharti Airtel, Aircel, Vodafone and Tata Indicom. Despite the rapid proliferation of telecom communication networks in the State, the benefits of Information Technology have yet to reach a large number of people, especially in rural areas. The telecom density in Jammu & Kashmir is good and has come to the level of an average. However, the PC penetration rate in the state is also extremely low. While there has been no systematic survey carried out for estimating PC penetration, a fair assumption would be that the State has penetration rates which are about the same as the national average(approx. 26%). The television cable network in the State has however seen rapid progress. The phenomenon of a digital divide poses several problems for developing countries all over the world. Unless concerted steps are taken to bridge this divide the developing countries are in danger of being left behind in the emerging digital economy. In order to address the problem of the digital divide it is necessary to take action on three fronts. Firstly, telecommunications infrastructure has to be put in place in order to provide affordable bandwidth for large sections of the community. Secondly, low cost information access appliances which are easy to learn and use by rural population have to be made available in large numbers, to increase IT penetration rates. Thirdly, content relevant to the lives of people needs to be developed and made available over networks. 4.1.2 Vision The vision of Government of Jammu & Kashmir is for the all round development of the State of Jammu & Kashmir. The Govt. of J&K has decided to establish the State-wide Information Technology Network referred as JKSWAN that would provide the basic Information Technology backbone for carrying voice, data and video traffic for all departments in the state which is necessary for effectively allowing government services to be delivered from the states data centre to customer premises locations (which are the State Head Quarters, District Headquarters, Block Headquarters, and various ministry and state offices within pre-defined distances of their respective headquarters.). The Government of Jam-

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mu & Kashmir recognizes the strategic importance of IT in improving the economy of the state as a whole. 4.1.3 Objective The Government of Jammu & Kashmir through Jammu & Kashmir e-GovernanceAgency (JaKeGA) under Information Technology Department, Govt. of J&K, is embarking on the state-wide automation of its operations and implementing e-Governance initiatives. Various departments of the government are in the process of developing and implementing software applications which will be hosted by the state data center. Also as an imperative of the e-government master plan, the government of Jammu & Kashmir intends to provide services on the Internet to its citizens in a secure and controlled manner. These services must be consistently available and have the capacity to grow, as requirements increase. The Network will provide secure links with sufficient speed and bandwidth to allow the exchange of information among the state departments and provide online services to the Public, regardless of location. The State Wide Area Network (JKSWAN) will support the framework/architecture necessary for secure and confidential electronic transactions. The network will support intelligent applications that monitor access to the infrastructure and if necessary, encrypt data to ensure the safe and secure transmission of information. The State Wide Area Network will implement platforms that promote open systems and interoperability. The key objectives of a State Wide Area Network are: To establish a state communications infrastructure to provide Government departments in the State Of Jammu & Kashmir ability to access the applications hosted by the state data centre. To provide robust communication infrastructure so that every citizen in the state has access to government services and information when and where they need. To move toward converged communications services (voice, data and video) by achieving a single centralized communication infrastructure for the state. Avoiding unnecessary movement of vehicles, employees and documents. Reduction in postal, courier and public telephone expenditure. Prompt disaster management. 29

Maintenance of law and order, quick tracking and capture of criminal and undesirable elements. 4.1.4 The Project aims The project aims to provide government administrative functionality over a robust communication backbone, including services to citizens under the Municipal Corporations and Collectorates. Some key objectives are: Avoiding unnecessary movement of vehicles, employees and documents. Reduction in postal, courier and public telephone expenditure. Prompt disaster management. Maintenance of law and order, quick tracking and capture of criminal and undesirable elements. JKSWAN a core infrastructure project under National E-Governance Action Plan is a joint venture project of GOI and Information Technology Department (ITD), GoJK. Under JKSWAN minimum 2Mbps connectivity is to be provided up to the Block level in the state of Jammu & Kashmir. In this regard, Government of Jammu & Kashmir acting through the JaKeGA under ITD, invites detailed Bid Proposals from interested parties (Bidders) in order to select a qualified party for implementing the project as above, in accordance with the terms and conditions of this document (hereinafter referred to as Tender Document). The party whose Bid Proposal is accepted by JAKEGA at the end of the bidding process (the Successful Bidder) may be awarded a Concession on Build Own Operate Transfer (BOOT) basis by JAKEGA to take up the Project. A draft of the Concession Agreement is provided in Part III of tender document The Concessionaire (the Successful Bidder, in case the Concession is awarded to it) shall be responsible for implementing the Project at its cost, expense and risk in accordance with the terms and subject to the conditions laid down in the Concession Agreement to be signed between the Successful Bidder and JAKEGA. Available data pertaining to addresses and location details of point of presence at State Head Quarter (SHQ), District Head Quarter (DHQ) and Block Head Quarter (BHQ) (referred as vertical offices) in the state of Jammu & Kashmir . 4.2 JKSWAN architecture JKSWAN is required to be open standards based, scalable, high capacity Network to 30

carry Voice, Data and Video traffic between designated Government of Jammu & Kashmir (GOJK) offices at State, District and Block levels. The connectivity to the end-user is based on standard technologies like leased circuits for the individual offices. The Network should have single point Gateways of adequate capacity to Internet. JKSWAN shall be built vertically on three tiers of

JKSWAN - OVERVIEW

Network connectivity comprising: 31

- Primary Tier consisting of SHQ - Secondary Tier consisting of DHQs - Tertiary Tier consisting of BHQs

JKSWAN OVERVIEW SIMULATION

4.2.1 State Head Quarters (SHQ) Tier-l will be the core of the JKSWAN at State Headquarter, which will be connected (vertically) to all the District Head Quarters (DHQs) PoPs (including state DHQs at Jammu and Srinagar), and other GOJK Offices & Departments in a city/town using horizontal connectivity mode. At SHQ the entire Sate Wide Area Network bandwidth is aggregated from all the connected GOJK offices. For JKSWAN SHQ will be facilitating e- Governance applications and services to GOJK Departments, Offices and Citizens. SHQ as first level tier of JKSWAN and will be located at Jammu. The GOJK Offices/ Departments in Jammu will be either connected to SHQ or DHQ at DC Office Jammu (horizontally) using n x 64 kbps 32

leased lines. However, co-located offices will be connected to SHQ/ DHQ using LAN technologies.

JKSWAN STATE WIDE CONNECTIVITY SIMULATION

4.2.2 District Head Quarters (DHQs) 33

This Tier-II of JKSWAN initially will be using 2 Mbps leased lines to connect the SHQ with District Head Quarters (DHQ) as vertical connectivity. These DHQs will be located at the respective DHQ PoP. There are Government Departments/ Organizations at the District level, which are spread over locations and will be connected to DHQ using n x 64 Kbps leased lines (horizontal). The co-located departments within the DHQ PoPs building will be accessing JKSWAN using LAN technologies directly on the LAN switch at DHQ.

JKSWAN DHQ CONNECTIVITY SIMULATION

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4.2.3 Block Head Quarters (BHQs) This Tier 3 will link DHQ with Blocks / Division/ Block Head Quarters to be located at the respective Sub-Division; Block head quarters using 2 Mbps leased lines. Each BLC will also be connected with other Government Offices at Sub Division/ Block level using n x 64 Kbps leased circuits. The co-located departments within the Block PoPs building will be accessing JKSWAN using LAN technologies directly on the LAN switch at BHQ.

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JKSWAN BHQ CONNECTIVITY SIMULATION

5. BIBLIOGRAPHY Books referred: 1. CCNA Cisco Certified Network Associate STUDY GUIDE by Todd Lammle 2. Computer networks by Andrew S. Tanenbaum3. Cisco IP Routing Protocols: Troubleshooting Techniques

CCNA Practical Studies Websites and eBooks: http://en.wikipedia.org/wiki/Ccna http://en.wikipedia.org/wiki/Routers http://en.wikipedia.org/wiki/switches http://en.wikipedia.org/wiki/ip protocols http://en.wikipedia.org/wiki/ipv6 http://en.wikipedia.org/wiki/frame relay www.lammle.com CCNA Study Guide an E-Book to clear CCNA CCNA v/s MCSE 36

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