Reverse ARP, Proxy ARP, Inverse ARP | Cabletron Systems DMS-100

162Appendix E: Understanding IP and IP addressing

Included in the family of address resolution protocols are reverse address resolution protocol (RARP), proxy address resolution protocol (proxy ARP), and inverse address resolution protocol (InARP).

ARP is deﬁned in RFC826.

Reverse ARP

RARP is used to determine or assign a particular station IP address when only the station LAN MAC address is known.

There are many reasons why an end system does not already have an IP address. The end-system could be a diskless workstation homed off a server. Or, it could be a portable computer belonging to an itinerant user, sharing a pool of IP addresses with other itinerant users.

RFC903 deﬁnes RARP.

Proxy ARP

The proxy ARP is used to help an IP device locate a destination device, when the destination device is on a remote IP network or wire. When a source station broadcasts an ARP request on the local wire, and there is no station matching the destination IP address on the wire, the source does not receive an ARP response from the actual destination. Instead, the router derives the destination IP wire address and searches for a match in its IP routing table.

If the destination IP wire address is present in the routing table, the router responds with its MAC address. This tells the source that the MAC address for the router is the MAC address for the destination station. The source IP station has no idea that the destination is on another wire.

Proxy ARP is deﬁned in RFC1027.

Inverse ARP

The inverse address resolution protocol (InARP) determines the IP address for a remote router on a particular frame relay data link connection identiﬁer (DLCI). This IP address is the local frame relay address of a permanent virtual circuit (PVC) to a remote router.

Inverse ARP is deﬁned in RFC2390.

Bootstrap Protocol

The bootstrap protocol (BOOTP) is a UDP/IP-based protocol that permits a booting host to conﬁgure itself dynamically and without user supervision.

BOOTP provides a means to notify a host of the following:

•its assigned IP address

297-8991-910 Standard 03.01 August 1999

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Cabletron Systems DMS-100 manual Reverse ARP, Proxy ARP, Inverse ARP, Bootstrap Protocol

Contents

Ethernet Interface Unit Page Ethernet Interface Unit Standard 03.01 August May Publication historyAugust March Vi Publication history Standard 03.01 August Contents EIU messaging protocols Chapter EIU datafill Appendix D Using telnet 141 EIU maintenance 103Appendix C Using FTP 117 Volume listing Appendix H ASU background information 177 Appendix I Obtaining a MAC address 185List of terms 189 List of figures Xii List of tables Xiii Xiv About this document When to use this documentHow to check the version and issue of this document References in this document Internet request for comment documents Xvi What precautionary messages mean Possible loss of serviceXvii Risk of electrocution How commands, parameters, and responses are representedRisk of personal injury Input prompt Commands and ﬁxed parameters VariablesResponses Standard 03.01 August Introduction to the EIU Possible loss of network security Overview of the EIU System architecture IOC DMS-bus interface and expansionSLM SOS Unix EIU Inter-message switch links required with LPP Data communications interface architecture Ethernet interface data ﬂow LAN Introduction to the EIU Hardware description AUI PBUTP PB Rear paddle boards Slot EIUFront cards DMS SuperNode switch LPP with an EIU SSLPP, with 2-slot EIU locations Top view of Sslpp shelf Ethernet interface card NT9X84 DMS SuperNode Flis with an EIU LPP NTEX22 CPU/IPF Ethernet physical interfacesAttachment unit interface-NT9X85AA MAU Capabilities, limitations, and restrictions Unshielded twisted-pair NT9X85BAGrounding requirements EIU hardware capabilities and limitations Introduction to the EIU Limitations associated with maintenance System-wide limitations Limitations associated with protocols Routing information protocol Internet Protocol and Internet Control Message Protocol Feature packagingDMS-Core feature packages Package Title Description NTXF05AA EIU provisioning requirements DMS-bus inter-MS provisioningSheet 2 Example of DMS-bus intermessage switch conﬁguration DMS-bus external MS provisioning EIU provisioning EIU sparing and redundancyNT9X17AA NT9X23BA Service orders User interface characteristicsBilling Possible loss of information Logs, alarms, and OMsAlarms Log reports Introduction to the EIU Standard 03.01 August EIU messaging protocols Shows the structure of the DMS-100 switch EIU protocol stack Software architecture FTP Telnet Snmp Bootp RIP TCP UDP Icmp ARPFTS Ethernet Ethernet LAN Workstation TCP/UDP FTSDMS-bus TCP Boot protocol Supported protocols File transfer protocol Wsls Internet Protocol Telnet User datagram protocol Address resolution protocolTransmission control protocol Internet control message protocol Addressing MAC addressesInternet addresses EIU messaging protocols How to get IP addresses for SuperNode What is the SuperNode network topology? Routing EIU messaging protocols APX LMS APUX10 LIU7APUX20 LIU7 Routing tables IP throttling Protocol engineeringIP Screening TCP connection management EIU APU UDP connection limits by SuperNode subsystemSubsystem Maximum UDP connections FTP session control Protocol buffer engineering Receive 1518 Icbm common pool 1024 128 Transmit TCP own IP throttling IP throttling for LPP IP throttling for Sslpp Application Sheet 2 EIU dataﬁll Interdependency and auto-conﬁguration Table Liuinv Link interface unit name Dataﬁll sequence and implicationsTable Liuinv dataﬁll Link interface unit type Link interface unit number Message switch cardMessage switch port Location Processor information Link interface slotSoftware load name Processor product engineering code EIU MAC addresses Sheet 4 Table Ipnetwrk IP addressesSample dataﬁll for table Liuinv Dataﬁll for table Ipnetwrk Ipnetwrk Ethernet interface unit. Enter EIU Computing module Internet ProtocolInternet Protocol network subnet range Ethernet interface unit range. Enter Dfltgtwyip Parm ScrnflagEiuinterface Addr Iomnum Sample dataﬁll for table IpnetwrkGtwyipaddr Packlet Table Iprouter Supplementary information Dataﬁll Table Iphost Ethernet address resolution protocolEthernet proxy address resolution Sample dataﬁll for table Iprouter Nodeidx IndexIndex Node index Node name Node Transmission control Protocol File processor indexInternet porotocol address SuperNode Connections Support Operating Switch Application processor Unix indexInternet protocol host identification for Cmindex Computing module index Internet protocol address for node EiuindexEthernet interface unit index Lanaddr Eliuindex Second IP address for Eliu host Nodename = MS Apux Sample dataﬁll for table Iphost Message switch indexTable Ipthron Msindex EIU datafill Local message switch node Transmit capacityReceive capacity Synchronized and matched node index OptionSuperNode node Application processor unit index Field descriptions for table Ipthron for EIU datafill Table IpprotoSample dataﬁll for table Ipthron Field Subfield or Entry Explanation and action Refinement Sample dataﬁll for table Ipproto IprsmtmoArprftmo Sample dataﬁll for table Ensites Table EnsitesTable Entypes Alphanumeric Entype Table ExndinvSample dataﬁll for table Entypes External node type Pmloads External node number External node keyExternal node peripheral module type External node name Machine address DMS boot protocolInternet Protocol address External node load file name Bay position Floor numberRow External node information External node alarm scan points External node no-link alarmExternal node one-link alarm Critical alarm scan point Sample dataﬁll for table Exndinv Major alarm scan pointMinor alarm scan point Sheet 5 EIU maintenance 103 Out-of-service diagnostics EIU diagnosticsIn-service state EIU MAP level In-service diagnostics In-service leaky bucket audit EIU overload control EIU sparing requirements Automated system maintenance EIU Eliu Manual system maintenance Logs relevant to EIU OA&M OMs relevant to EIU OA&M Appendix a EIU installation checklist 111 Consult the DMS-100 PM Software Release Document SoftwareNTXF05AA EIU Datafill Appendix B EIU troubleshooting 113 Troubleshooting checklist EIU troubleshooting checklist Problem Probable causeTools Sheet 2 Appendix B EIU troubleshooting Standard 03.01 August Appendix C Using FTP 117 What is FTP? Automatic Record Length DetectionWhere DMS FTP cookbook Volume listingFTP on the DMS-100 switch File name conventions DMS FTP client commands FTP commands on the DMS-100 switch Command Description Obtaining the IP address of the SuperNode host Tutorial basic FTP operations Procedure 1 Establishing an FTP session Step ActionWhere Userid Is a valid userID for that host Ftp ‘nnn.nnn.nnn.nnn ’Page Ftp cd ‘/team/bin’ Ftp dirFtp cd pathname Ftp lcd pathname Where Pathname Is a valid directory path Example Tutorial moving ﬁlesIf the file Ftp lcd ‘/S00DTEMP’ If the filenameFtp lrecl Ftp get ‘ﬁle1.dmo ’ Ftp get ‘ﬁle1.txt54 ’Ftp put ‘RECORDFILE’ ‘jan18.log’ Ftp cd ‘ /team/bin’ Ftp get ‘ﬁle1.bin’ Procedure 7 Showing the status of server sessions Tutorial advanced operationsFtp get ‘ﬁle1.bin1020’ Procedure 9 Remove a server userID and unreserve a session Ftp svreserveFtpadduserinfo ‘johnh’ ‘johnh’ ‘/S00DTEMP’ y Where Userid Is the userID Example Procedure 10 Adding a userID with limited set of commandsFtpdeluserinfo ‘johnh’ Ftp commandmask mkdir set Procedure 11 Adding a userID with a new command timeout Ftpcommandtimeout FtpcommandmaskFTP operations reference WS cd /pathname WS ftp IPaddressWS pwd WS lcd /directory WS site Lrecl WS asciiWS get filename WS put filename Newfilename CM Ftpopen ‘IPaddress’ WSput filename.image FilenameWS put filename.sosimage Filenameunipl CM FTP ‘IPaddress’ CM lcd CM cd ‘pathname’CM lcd ‘/PATHNAME’ CM ls CM get ‘filename.load68k’ CM put filenameCM binary CM get ‘filename.bin1020’ Appendix D Using telnet 141 Telnet access to a switch Table Ipnetwrk Appendix D Using telnet Standard 03.01 August What is internetworking? Appendix E Understanding IP and IP addressing145 What is routing? Routing and routed protocols Planning overview Mapping the network Simple network map Detailed network diagram Choosing IP addresses IP address structure Class Range Description Class Range Description IP addressing class a Subnet mask class a Class a subnet masks IP addressing class B Subnet mask class B Class B subnet masks IP addressing class C Address masks IP addressing class D Network numbering example Address mask example Network node Firewalls and network security Simple network numbering Variable-width subnetworks Protocols related to Internet Protocol Internet control message protocol Proxy ARP Bootstrap ProtocolReverse ARP Inverse ARP Open shortest path ﬁrst Page Appendix F EIU supported conﬁgurations 165 Host conﬁguration Router conﬁgurations Host and router conﬁguration Interface conﬁguration part Subnet ClassA .networkidB .subnetX .hostZ 47.105.150.3 Considerations for obtaining IP addresses Appendix G IP network number requestsOverview 171 NIC IP network number request form NIC IP address request formYour Application Must be Typed Sheet 2 Sheet 3 Sheet 4 Appendix G IP network number requests Standard 03.01 August Link interface unit Application-speciﬁc units and supported servicesAppendix H ASU background information Ethernet interface unit Frame relay interface unit 25/X.75 link interface unit Network interface unit Voice processor unit and AdasASUs and Cellular digital packet data Platforms External routersLink peripheral processor LPP architecture ASU Single-shelf link peripheral processor On page 183 provides an overview of the Sslpp conﬁguration SuperNode SE link interface shelf Sslpp architecture SNSE-LIS architecture Shelf Appendix I Obtaining a MAC address MAC address format185 EIU MAC address format How to get the MAC address for an EIU Appendix I Obtaining a MAC address Standard 03.01 August List of terms 189 List of terms LIS MTP List of terms UDP Page Ethernet Interface Unit