ELSA Cable manual Network technology, Network and its components, Connection modes

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50Technical basics

Network, transmission medium, interfaces

Packets

Cells

Host

Router

Network technology

This section will give you a brief introduction to the basics of network technology. These descriptions do not cover all possible techniques, processes and terms associated with network technology. They only cover the topic to the degree necessary to provide an understanding of the product information.

The network and its components

Whenever several computers communicate with one another, this connection is called a network. For computers to be able to communicate, they need a physical medium through which the information can be transmitted. This can be a cable or radio link, for example, that is connected to the computers using special interfaces (e.g. network adapters).

The term network cable (or simply cable) in the following text also refers to any other physical medium that can take on the function of the cable, such as wireless links.

The individual bits of electronic information that are sent from one computer to another through a medium are called packets or cells, depending on the process.

For most of the following explanations, the difference between packets and cells is irrelevant. Therefore, we will use the term packet or data packet in a general sense and only detail the special characteristics of cells as necessary.

The computer and other terminal devices (e.g. the printer) in a network that generate or process information are called hosts. Ideally, a host is not responsible for the task of forwarding information. A host normally has exactly one interface to the network.

The transport of packets between two hosts occurs indirectly through exchanges that pass packets on to the target computer. These exchanges are called routers. A router has at least two interfaces so that it can receive the data from a sender and pass them on to a recipient. Apart from the exchange function, the router also has the properties of a host so that it can also be the recipient of data packets, for configuration purposes for example.

Point-to-point connection

Connection modes

The connection of exactly two hosts via a medium is called a “point-to-point connection”. In this case a host sends packets that can only be received by one specific recipient (unambiguous connection).

ELSA MicroLink Cable

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Contents Manual Aachen ELSA, IncSonnenweg GermanyThank you for placing your trust in this Elsa product Introducing the Elsa MicroLink CablePage Content Elsa Cable ModemVI Content Setup/SNMP-module Viii Content Introducing the Elsa MicroLink Cable What does the unit look like?Elsa MicroLink Cable Meanings of the specific blink codes SyncBC D E F G These LEDs show the corresponding network controller statusFast Internet Highlights of the Elsa MicroLink CableNode or hub? Cable networkMore than just Internet Regional contentInternet at all times-always online BackboneProxy servers CE conformity and FCC radiation standard CE and FCCIntroducing the Elsa MicroLink Cable Installation and configuration Elsa MicroLink CableConfiguring the Elsa MicroLink Cable First StepsConfiguration as a bridge Quick Start Quick configurationsPreparations LAN Configuration as a router Off you go into the Web with a whole new sensation of speedOn the Router tab, enable the IP Router option Configuring fixed IP addresses not using Dhcp TCP/IP installationObtain IP addresses automatically use Dhcp Checking the IP configuration Configuration modes Requirements for inband configurationUser-friendly method inband Starting inband configuration using Elsa LANconfig Start up inband configuration using telnetConfiguration commands This command Means this For instanceSet/se/snmp/admin The Administrator Whats happening on the line? How to start a traceCommand to call up a trace follows this syntax Trace OutputsThis is how FirmSafe works New firmware with FirmSafeExamples How to load new software Elsa LANconfigConfiguration using Snmp General TftpAccess protection in Snmp Accessing tables and parameters using SnmpCommand Target/Source Function Appending rows to tables using Snmp Deleting rows in tables using SnmpIP address IP-netmask Router name Distance Error messages via Snmp trap Management Information Base MIBConfiguration modes Login barring Security for your configurationPassword protection Operating modes and functionsSecurity for your LAN Access control via TCP/IPGlobally to TCP/IP packet filters EncryptionHiding place-IP masquerading NAT, PAT IP routing table IP routingIP address IP netmask Router Dis Tance IP address IP netmask Router name Dist This is what happens 192.168.130.0 255.255.255.0What do the entries mean? Dynamic routing with IP/RIPWhat information is propagated by IP/RIP? IP address IP netmask Time Distance RouterLocal routing Interaction of static and dynamic tablesIP masquerading NAT, PAT Two addresses for the routerCable TV net How does IP masquerading work?Simple and inverse masquerading WorkDNS forwarding Which protocols can be transmitted using IP masquerading?Only small difference is that Bridging RatorAutomatic address administration with Dhcp What are the filter options?Cable modem really belongs to two LANs Dhcp clientDhcp server IP address Network mask Broadcast addressHow are the addresses assigned? Default state is autoDhcp on, off or auto? IP address assignmentBroadcast address assignment Default gateway assignmentNetwork mask assignment DNS server assignmentPriority for the Dhcp server Request assignment Priority for a workstation-overwriting an assignmentOperating modes and functions Operating modes and functions Elsa MicroLink Cable Cable modem technology AccessTwo standards get around this problem StandardsNetwork of the cable network Cable TV net Registration in the cable networkOperator Work Registration Network and its components Network technologyConnection modes Host IP addressing Kinds of networksSame IP address, this time with another netmask ExamplesThis address Bytes Looks like this in bits IP address Netmask Remark 10.0.0.0 255.0.0.0There are two considerations when using these IP addresses IP routing and hierarchical IP addressingHost Smith External host Marketing Example Expansion through local networks Easy as possible Why a LAN is called multiprotocol-capable80-C7-6D-A4-6E That is processed by all computers in the LANInterface only understands MAC addresses Data transfer within the LANLAN as easy as possible Host Smith Data transfer from the LAN onto the Internet LAN coupling on MAC basisTechnical basics Elsa MicroLink Cable Technical data AppendixPackage contents ServiceWarranty period Warranty conditionsWarranty coverage Warranty procedureOperating mistakes Additional regulationsDeclaration of conformity TypenbezeichnungAppendix Elsa MicroLink Cable Index 17, 32 Inde7032, 40 Gateway Heap reserve 17, 18Setup TraceWireless links Inde72Symbols Description of the menu options R73R74 Description of the menu options Overview of the menusDescription of the menu options R75 StatusStatus Running status displays Status/Cable-statistics Status/Operating-timeStatus/Current-time R76 Description of the menu optionsDescription of the menu options R77 Status/LAN-statisticsLAN-statistics Running status displays Cannot be modified manually Status/Bridge-statisticsR78 Description of the menu options Bridge-statistics Running status displaysStatus/TCP-IP-statistics/ARP-statistics Status/TCP-IP-statisticsDescription of the menu options R79 These statistics include the following valuesStatus/TCP-IP-statistics/IP-statistics R80 Description of the menu optionsStatus/TCP-IP-statistics/ICMP-statistics Status/TCP-IP-statistics/TCP-statistics Description of the menu options R81Status/TCP-IP-statistics/TFTP-statistics R82 Description of the menu options Status/TCP-IP-statistics/DHCP-statisticsShrinks accordingly. It has the following layout Status/IP-router-statisticsDescription of the menu options R83 IP-router-statistics Statistics from the IP router areaProtocol LAN-tx Cable-tx R84 Description of the menu optionsStatus/IP-router-statistics/RIP-statistics IP-address IP-netmask Time Distance RouterStatus/Queue-statistics Status/Config-statisticsConfig-statistics Remote configuration statistics Description of the menu options R85R86 Description of the menu options IPr-RIP-queue-packetsDescription of the menu options R87 Status/MCNS-statisticsStatus/Init-status MCSN-statisticsStatus/DHCP-client-statistics SetupSystem configuration R88 Description of the menu optionsEntering the following command Setup/Cable-moduleSetup/LAN-module Default configuration, no name is enteredSetup/Bridge-module R90 Description of the menu optionsDescription of the menu options R91 Setup/TCP-IP-moduleMAC-address field Configuration, the TCP/IP module is activated R92 Description of the menu optionsDescription of the menu options R93 IP-address Node-ID Last-access Connect Setup/IP-router-moduleConfiguration, the IP router module is activated IP-router-module IP router module settingsDescription of the menu options R95 IP-address IP netmask Router-name DistanceRouting-method Routing method settings Setup/IP-router-module/Routing-methodR96 Description of the menu options Settings have the following meaning Setup/IP-router-module/RIP-configurationDifferent settings have the following meaning Description of the menu options R97R98 Description of the menu options Setup/IP-router-module/MasqueradingFollowing layout Setup/IP-router-module/firewall Description of the menu options R99R10 Description of the menu options Description of the menu options R10 Setup/SNMP-moduleSetup/DHCP-server-module On The device operates as a Dhcp serverOff The device does not operate as a Dhcp server Default value of 6000 minutes equals approximately 4 daysR102 Description of the menu options Network mask is assigned in the same way as the IP addressConfig-module Configuration module settings Setup/Config-moduleIP-address Node-ID Timeout Hostname Type Description of the menu options R103Firmware Firmware Display and keyboard settingsR104 Description of the menu options Module Version Description of the menu options R105Position Status Version Date Size Index R106 Description of the menu options This option allows you to reboot the deviceOther Other menu allows you to manage the following functions