Introduction To IP Addressing And Networking

NETWORKING BASICSA network can be defined as the interconnection of autonomous computers linked together to facilitate communication, and networking is the simple concept of linking and networking have grown exponentially computers.Networks over the past 15 years, is have evolved at light speed just to keep pace with huge increases in basic user needs critical investigation such as sharing data and printers, as well as more advanced research needs of network video conferencing.TYPES local area network (LAN) A LAN (Local Area Network) is a group of computers and network devices connected together, usually in the same building. A Local Area Network (LAN) is a high-speed communications system designed to connect computers and other computing devices together in a small geographic area, examined a workgroup, department or building. Local Area Networks implement shared access technology. This means that all devices connected to the LAN share a single communications medium, usually a coaxial, twisted pair or fiber optic cable.METROPOLITAN AREA NETWORK (MAN) Metropolitan Area Networks or MANs are large computer networks usually cover a city ​​or town. Typically use wireless infrastructure or optical fiber connections to link their sites.The IEEE 802-2001 standard describes a man as: "A man is optimized for a wider geographical area than is a LAN from different blocks of buildings to entire cities. MAN may also depend on the channels of communication to be moderate to high data rates. a man could be owned and managed by one organization, but usually will be used by many people and organizations. MAN could also be owned and operated as public utilities. They often provide means for internetworking of local networks. metropolitan area networks can span up to 50 km. "Wide Area Network (WAN), Wide Area Network (WAN) is a network of computers that covers a large area. A WAN compares to a man, is not limited to a geographical location, although it could be limited to certain geographic locations, may also be limited within the boundaries of one state or country. A WAN connects several LANs and may be limited to company (a company or organization) or accessible to the public.The technology is the high speed and relatively expensive. The Internet is an example of a worldwide audience WAN.NETWORKING Router router devices are used to connect the networks together and route the data packets from one network to another. Routers, by default split a broadcast domain, which is the set of all devices on a network segment that hear all broadcasts sent to segment.Routers So break collision domains. This is a term used to describe an Ethernet network scenario in which a device sends a packet on a particular network segment, forcing every other device on that segment to pay attention to it. At the same time, a different device attempts to transmit, leading to a collision, both devices must retransmit after which one at time.Routers performed on the layer 3 of OSI (Open System Interconnection) reference model.SWITCHESSwitches are used for network-based segmentation MAC addresses. Switches to watch the arriving frame hardware addresses before deciding to forward the frame to break or fall it.Switches collision domains, but the hosts on the switch are members of a great silent transmission domain.HUBA hub is actually a multiple-port repeater. A repeater receives a digital signal and re-boost the signal or bone regeneration, and then sends the digital signal on all active ports without looking at data. An active hub does the same thing. This means that all devices connected to a hub are in the same collision domain as well as in the same broadcast domain, which means that the devices share the same bandwidth. Hubs operate at the physical layer of the OSI IP Address model.IP InGaN is a numerical identifier assigned to each machine on an IP network. It designates the specific location of a device on the network. An IP address is a software designed to help address and host on a network to communicate with a host on a different network, regardless of the type of LANs the hosts are participating in.IP TERMINOLOGIESBit: A bit is a digit, a 1 or a 0.Byte: A byte is 8 bits or 7, depending on whether the parity is used.Octet: an octet consists of 8 bits is just a normal 8-bit binary number. In most cases of bytes and octet are completely address interchangeable.Network: This is the designation used in routing to send packets to a remote network. For example, 10.0.0.0, 172.16.0.0, and 192.168.10.0 network are addresses.Broadcast address: the address used by applications and hosts to send information to all nodes of a network is called a broadcast address. Examples include 255 255 255 255 which is all networks, all nodes, 172.16.255.255, which is all subnets and hosts on the network IP address 172.16.0.0.HEIRARCHICAL SCHEMEAn IP address consists of 32 bits of information (IPv4). IPv6, a new version of IP is composed of 128 information bits. The 32 bits is divided into four sections referred to as IP octets or bytes, each containing 1 byte (8 bits). An IP address is represented with any of these three decimal places methods.Dotted, as in 172.16.30.56Binary, as in 10101100.00010000.00011110.00111000 hexadecimal, as in the examples represent the same AC.10.1E.38All this IP address. But the most commonly used is the dotted decimal notation. The Windows registry stores the IP address of a machine hex.The 32-bit IP address is a structured or hierarchical address, as opposed to an apartment address is not hierarchical. Although both types of addressing scheme could be used, facing the hierarchical chosen for a good reason. The advantage of this scheme is that it can handle a large number of addresses for sale, Billion That is to say 4.3 (32-bit address space, with two possible values ​​for each position that is either 1 or 0, and gives 237 or 4294967296). The disadvantage of the plan addressing scheme reference to routing. If every address were unique, all routers on the Internet would need to store the address of every machine on the Internet. This would make efficient routing ADDRESS impossible.NETWORK RANGEThe network address uniquely identifies each network. Every machine on the network shares the same network address as part of its IP address. The IP address of 172.16.30.56, 172.16 is the address of the network node is assigned to address.The and uniquely identifies each machine on the network. This number can be referred to as the host address. In 172.16.30.56, 30.56 is the address of the node. Class A network is used when a small number of networks posse sing a very large number of nodes are needed. Class C network is used when many networks with a small number of node A is needed.CLASS ADDRESSESThe first bit of the first byte in a class A address of the network must always be turned off or 0th This means that a class A address must be between 0 and 127, we turn the other 7 bits all off and then turn inclusive.0xxxxxxx.hhhhhhhh.hhhhhhhh.hhhhhhhhIf of all, we will find the class of a series of network addresses.00000000 001111111 = A = 127Class network.node.node.node is format, so for example the IP address 49.22.102.70, 49 is the network address and 22.102.70 is the address of the node. Every machine on the network may have a particularly distinctive network address bits B 49.CLASS ADDRESSESThe before the first byte must always be on, but the second bit must always be directed off.01xxxxxx.xxxxxxxx.hhhhhhhh.hhhhhhhhIf we can address the first bits on and off and the second bit if the other six pieces all out and then all one, we will find the class B network range addresses.10000000 = format = 12810111111 191Class network.network.node.node B is, so far address IP 132.163.40.57, the 132 163 is the network address of the node and 40.57 is the first and the second ADDRESSESThe address.CLASS bit C of the first byte must be always on, but the third bit can never be on. 110xxxxx. xxxxxxxx.xxxxxxxx.hhhhhhhhIf turn the tip first and second and third bit off and then all the other 5 bits all off and all of them away, we will find the range of Class C network address.11000000 = 19211011111 = C network.network 223Class format. network.node is, for example the IP address 195.166.231.75, the 195 166 231 is the network address and the node 75 is address.CLASS D and class E address ADDRESSESThe between 224 and 255 are reserved for the class DE and networks. Class D (224-239) is used for multicast addresses and Class E (240-255) for scientific purposes.PRIVATE ADDRESSESPrivate IP IP addresses are those that can be used on a private network, but are not routable over the internet. This is designed to create a measure of well-needed security, but also conveniently saves valuable IP address space. If every host on each network had to have real IP addresses routing, we would run out of IP addresses to distribute ago.Class years A 10.0.0.0 B 172.16.0.0 through 10.255.255.255Class 172.31.255.255Class C with 192,168. 0.0 192.168.255.255TROUBLESHOOTING IP troubleshooting steps are ADDRESSINGHere to solve a problem until network.1 IP. Open a DOS window and ping 127.0.0.1. This is the address or loopback diagnostic, and if you get a successful ping, the IP stack is considered to be initialized. If it fails, then you have an error in the IP stack and the need to reinstall the TCP / IP on host.2. From the DOS window, ping the local host IP addresses. If this is successful, then your Network Interface Card (NIC) card is working. If it fails, then there is a problem with the NIC. This does not mean that a cable is connected to the network card, only the IP protocol stack on the host can communicate to NIC.3. From the DOS window, ping the default gateway. If ping works, means that the adapter is connected to the network and can communicate on the local network. If it fails, then you have a local physical network problem that could happen anywhere from the NIC to gateway.4. If steps 1 through 3 were successful, try to ping the remote server. If this works then you have the IP communications between then localhost and the remote server, then you know that the physical network remote working.5. If you silently communicate with the server after steps 1 to 4 have been successful can not, then there is probably a resolution problem and there is no need to check the domain name server (DNS), Network settings.NETWORK ADDRESS Address Translation Translation (NAT) is used mostly to translate addresses within a private network to a global address to the outside. The main idea is to save the global Internet address space, but also increases network security by hiding internal IP addresses from external networks.TABLE 3: BENEFITS AND NAT DISADVANTAGESADVANTAGESConserves addresses.Reduces legally registered address overlap occurrence.Increases flexibility in connection internet.Eliminates address renumbering as changes.Translation delaysDISADVANTAGESLoss path switching network introduces end-to-end application does not work with NAT traceabilityCertain enabled.TYPES NATStatic THE NAT: This type of NAT is designed to allow one-to-one between local and global addresses. Static NAT requires that there is a real IP address for each host on your internet network.Dynamic NAT: This version gives the possibility to map the IP address registered to a registered IP address from outside of a pool of registered IP addresses.Overloading: This is also known as Port Address Translation (PAT). And 'the most popular type of NAT configuration. Overloading is a form of dynamic NAT that maps multiple IP addresses registered to a single registered IP address using different ports. With thousands of users overloading you can connect to the internet using a single global address.NAT IPIndirizzi local real Terminologies: Name of local host addresses before translation.Global: Name of local addresses after translation.Inside: Name inside source address first translation.Outside local hostname of the destination before the global translation.Inside: Name of hosts after translation inside outside global host name of the destination switching off after translation.LAYER2 SWITCHINGLayer2 is the process of using the hardware address of devices on a LAN to a network segment. The term is used because Layer2 switching switches operate on the data link layer, which is the second layer of the OSI reference model.Layer2 Considered switching is based on hardware bridge because it uses specialized hardware called application specific integrated circuit (ASIC). ASICs can run up to gigabit speeds with very low latency rates.Switches read every frame that passes through the network, layer 2 device then puts the source hardware address in a filter table and keeps track of which port has been received frames. The information (recorded in the table filter of the switch) is what helps my deterministic machine the position of a sending device specific. After a filter table is built on layer2 device, it will only forward frames to the segment which is the target hardware. If the target device is on the same segment as the frame, the layer 2 device will block the frame from going to any other segment. If the destination is a different segment, the frame can be transmitted to the segment. This is called a transparent BRIDGING.When interface switch receives a frame with a hardware address of destination that is not found in the table device filters, it will forward the frame to all the connected line segments. If the unknown device that was sent responses of frame relay to this action, updates exchange the filter table on which the device location.ADVANTAGES OF Layer2 SWITCHINGThe biggest benefit of LAN switching hub-centered implementations is that each device on each segment connected to a switch that will send silmatenously whereas the hubs only allow one device to the network segment to communicate at a faster router time.Switches why not take time to look at the network layer header information. On the contrary, look at the hardware address of the frame before deciding whether to forward or drop the frame it.Switches create collision domains dedicated private and to provide the bandwidth independent of each port in contrast to hub. The following figure shows five hosts connected to a switch, all running 10Mbps half duplex on the server. Unlike the hub, each host has 10Mbps dedicated communication to server.LIMITATIONS OF Layer 2 switching switched networks break up collision domains, but the network is still a large broadcast domain. This not only limits the size of the network and the potential for growth, but may also reduce its overall performance.FUNCTIONS There are three distinct Layer2 switching functions of layer2 switching, these avoidance.ADDRESS decisionLoop areAddress learning.Forward / filter Learn If a sensor is first turned on, the attacker / MAC filter table is empty. When a device receives and transmits the frame interface, the switch places the source address frame forward / filter MAC table, which reminds you that the interface of the sending device is located. The switch then has no choice but to flood the network with this frame from every port except the source port because it has no idea where the destination device is actually a device located.If meets the frame and sends a frame flooded again, then the switch will have source address from that frame and place the MAC address in its database as well, associating this address with the interface that received the frame. Since the switch has now both relevant MAC addresses in its filtering table, the two devices can make a point to point connection. The switch does not need to flood the frame as did the first time.If there is no communication to address within a particular A certain amount of time, the sensor wire entry from the database to keep it as updated can. FORWARD / filter decision When a frame arrives at the switch interface, the target hardware address is compared to the forward / filter MAC database. If the destination address is unknown and hardware listed in the database, the frame is only sent out the correct switch interface.The interface does not transmit any frame except for the destination interface. This conserves the bandwidth on the network segment and another is called FRAME two switches are connected together FILTERING.LOOP AVOIDANCEWhen, redundant links between switches are a good idea because they help complete preventDefault network errors in the connection where a stop link working.Redundant are extremely useful but often cause more problems than they solve, this is because frames can be flooded down all redundant links silmatenously the creation of a network protocol called loops.Switches use STP (Spanning Tree Protocol) created by Digital Equipment Corporation (DEC), Compaq now to avoid network loops by shutting down redundant links. With STP running, frames will be transmitted only on the STP-picked premium link.CONFIGURING THE SWITCH CISCO Catalyst 2950 Switch House 2950 is a Cisco Catalyst family of high-end model. The 2950 is available in many flavors and run all the way up to 10Mbps switched ports and 1 Gbps twisted pair or fiber. They can provide basic data, video and voice services.2950 start switch when the switch is turned on for the first 2950, ​​you go through a Power-On Self Test (POST). At first, all port LEDs are green, and if after the completion of mining deterministic post that all doors are in good shape, all LEDs flash and then turn off But if POST finds a port that has failed both the system is LED and LED port amber.However turn, unlike a router, the switch is actually usable in the Fresh-out-of-the-box condition. You can just connect the switch to the network and connect network segments, with no configuration.To connected to Cisco switches, use a rolled Ethernet cable to connect a host to a switch port serial communication console Once you have connected the correct cable from your PC to a Cisco switch, you can start HyperTerminal to create a console connection and configure the device as follows: 1 Open HyperTerminal by clicking Start, then All Programs, then Accessories, then Communications, then click HyperTerminal. Enter a name for the connection. It is irrelevant what you name it. Then click OK.2. Choose the communication port COM1 or COM2 is, whatever is open on the PC.3. Now the port settings. The default values ​​(2400bps and no flow control hardware) does not work, you must set the port settings as shown in the figure that the bit rate is below.Notice in 9600 and set the flow control is set to none. Then click OK and press Enter, and you should be connected to your Cisco switch console port.Here 's initial release of the 2950 switch: --- System Configuration Dialog --- Would you like to enter the window initial configuration? [Yes / no]: RETURN noPress to start 00:04:53:% LINK-5-CHANGED: Interface vlan1, changed state to administratively down00: 04:54:% LINEPROTO-5-UPDOWN: Line protocol on Interface vlan1 , changed state bassoSwitch the> switch CONFIGURATIONThe> request user exec mode is called and is mostly used to display statistics. You can view and modify the configuration of a Cisco switch in privileged exec mode you get into with the enable command.Switch> Switch> Switch # # EnableSwitch disableSwitch> The global configuration mode can be entered from privileged mode using the configure terminal t control or configuration breve.Passa tImmettere # config configuration commands, one per line, ending with CNTL / Z.Switch (config) # zenithZenith hostname (config) # hostname command is used in naming the switch. The host name of a switch is significant only locally, but it is still useful to set a hostname on a switch that you can identify the switch when the connection to the Sun it.SETTING OF WAY LINE AND PASSWORD TO ENABLE PASSWORD.Zenith > # config enableZenith tenter configuration commands, one per line, end with CNTL / Z.Zenith (config) # enable password database zenith (config) # enable secret database middleThe enable password command sets the enable password as the secret banking and central command sets the enable password enable secret as middleware. The enable secret password is more secure and supersedes the enable password if set. The enable secret password and the enable password can not be the same on switch.Zenith 2950 (config) # line? First lineNumber console Primary terminal linevty Virtual Terminal Zenith (config) # line vty? First lineNumber zenith (config) # line vty 0 15Zenith (config-line) # login zenith (config-line) # password alexZenith (config) # line with 0Zenith (config-line) # login zenith (config-line) # password maloudaZenith (config) # exit zenith (config) # exit # zenith line vty 0 15 login and password commands to set the password telnet alex Alex and the line with 0, login and password commands Malouda set the password for console INFORMATIONYou IP Malouda . SETTING is not necessary to set an IP configuration on the switch to make it work. Just plug it in. But there are two reasons why the information about the IP address on September software.To switch.To manage the switch via telnet or other managers to configure the switch with different VLANs and other network functions.Zenith (config) # int vlan 1Zenith (config-if) # ip address 172.16.10.17 255.255.255.0Zenith (config-if) # no shutdown zenith (config-if) # exit zenith (config) # ip default-gateway 172.16.10.1Zenith (config ) # The IP address is 172.16.10.17 and set the shutdown command should not be applied to allow interface.CONFIGURING INTERFACE DESCRIPTIONSYou can administratively set a name for each interface on the switches with the description command.Zenith (config) # int fastethernet 0 /? Fast Ethernet interface number.Zenith (config) # int fastethernet 0/1Zenith (config-if) # description Sales LANZenith (config-if) # int f0/12Zenith (config-if) # description connection to the mail server zenith ( config-if) # CNTL / ZZenith # You can look at the descriptions at any time either with the command show interface or show running-config command from global configuration mode.ERASING and saving the configuration of switchZenith # copy running-config startup-configZenith # erase startup-configuration command copies the first configThe in NVRAM (Non-Volatile RAM), while the erase startup-config command to erase the switch configuration.Zenith # erase startup-configErasing the nvram filesystem will remove all files! Continue? [Confirm] [Enter] [OK] to erase nvram: complete zenith # Virtual LAN (VLAN) A virtual LAN (VLAN) is a logical grouping of network users and resources connected to administratively defined ports on a switch. When creating the VLANs, it creates smaller broadcast domains within a system of switched networks by assigning different ports on the switch to different subnets. A VLAN is treated like its own subnet or broadcast domain, which means that the frame of broadcast network are only switched between ports logically grouped within the same VLAN.Per default, no host in a specific VLAN can communicate with other hosts that are members of another VLAN.1.5 ADVANTAGES OF VLANA group of users who need security can be put into a VLAN that Sun users can not communicate with VLAN them.As out of a logical grouping of users by function , VLANs can be independent of their physical or geographic Considered locations.VLANs can improve network security.It can block broadcast storms caused by a faulty NIC (Network Interface Card) card.VLANs increase the number of broadcast domains while reducing Their MEMBERSHIPVLANs sizes.VLAN are usually created by the administrator, who assigns switch ports to each VLAN. This VLAN is called static VLANs. If the administrator wants to do the job a little 'earlier and assign all the host device hardware addresses into a database, so the switch can be configured to assign VLANs dynamically whenever a host is connected to a switch. This is called dynamic VLAN VLAN.STATIC VLANsStatic are the usual way to create VLANs, and are also the safest. The switch port that you assign a VLAN association to always maintain that association until an administrator manually changes that port assignment.DYNAMIC VLANsA mines deterministic dynamic VLAN assignment for a node automatically. Using intelligent management software, you can base the allocation to hardware addresses, protocols, or even to create dynamic applications VLANs.An example is a service of the VLAN Management Policy Server (VMPS) used to create a database of MAC addresses that can be used for the dynamic addressing of VLANs. A VMPS database maps MAC addresses to VLANs.FRAME frames were inserted TAGGINGAs the network, switches must be able to keep track of all the frames. Frames are handled differently depending on the type of connection you're going through. The identification method of the frame assigns uniquely defined by the user ID for each frame. This is sometimes referred to as the "VLAN ID". Each switch that the frame reaches must first identify the VLAN ID tag from the frame, and then finds out what to do with the frame, looking for information in the filter table. If the frame reaches a switch that has another link frame, the frame will be transmitted on the trunk link frame port.Once reaches out to access the appropriate link to the frame VLAN ID, the switch removes the VLAN identifier. This is so the destination device can receive the frame without understanding their identification.There VLANs are two types of links in a switched environment, are: Link Access: This type of connection is only a part of a VLAN. Each device connected to the link to access is not aware of a VLAN, the device takes only part of a broadcast domain. Connecting devices to access can not communicate with devices outside their VLAN unless the packet is scheduled instradato.Collegamenti: trunk links can carry multiple VLANs. A trunk link is a 100 or 1000 Mbps point to point link between two switches, between a switch and server. These carry traffic of VLANs 1-1005 at a time. Trunking allows you to make a single port to multiple VLANs at the same time. It also allows VLAN to span multiple IDENTIFICATION switches.VLAN There are basically two ways Method frame tagging.Inter-Switch Link (ISL), IEEE 802.1QThe main purpose of the ISL and 802.1Q frame tagging methods is to provide interswitch VLAN communication. Inter-Switch Link (ISL) Protocol: This is owned by Cisco, and is used for Fast Ethernet and Gigabit Ethernet links only. ISL routing can be used on a switch port, router interfaces, and interface cards to trunk a server server.IEEE 802.1Q: Created by the IEEE as a standard method of frame tagging, Cisco proprietary trunking is not as if you're between Cisco switched link and a different brand of switch, you must use 802.1Q for the trunk link work.VLAN Trunking Protocol (VTP) was created this protocol from Cisco, but not the owner. The key goals of VLAN Trunking Protocol (VTP), all VLANs are configured to manage through a switched internetwork and to maintain consistency across the network. VTP allows an administrator to add, delete and rename VLANs on a switch, that information is then propagated to all other switches in the VTP domain.Before you can get VTP to manage VLANs across the network, you must create a VTP server ....