References, Forwarding to Nodes within an LIS | 3Com 2500 specs

IP Routing References

4-11

Forwarding to Nodes within an LIS

Nodes can forward packets directly to other nodes in the same LIS. To forward a packet within the same LIS, the sending node requests a translation from the destination IP address to the corresponding ATM address from the ATM ARP server.

■If the address is known to the server, the server returns a message with this address

■If the address is not known to the server, the server returns a message to advise the sending node that the packet is discarded.

When the server returns a destination address, the sending node uses this learned address to create a virtual circuit (VC) and to forward this and all subsequent packets to the destination address. The sending node adds this VC to its ATM ARP cache.

IP Routing	Comer, Douglas E. Internetworking with TCP/IP. Volume I: Principles, Protocols,
References	and Architecture. Englewood Cliffs, New Jersey: Prentice Hall, Inc., 1991.
	Perlman, Radia. Interconnections: Bridges and Routers. Reading,
	Massachusetts: Addison-Wesley Publishing Company, Inc., 1992.
	Sterns, Richard. TCP/IP Illustrated. Volume 1: The Protocols. Reading,
	Massachusetts: Addison-Wesley Professional Computing Services, 1992.
	RFC 791. Internet Protocol Speciﬁcation.
	RFC 792. Internet Control Message Protocol Speciﬁcation.
	RFC 1009. Requirements for Internet Gateways.
	RFC 1042. A Standard for the Transmission of IP Datagrams over IEEE 802
	Networks.
	RFC 1058. Routing Information Protocol.
	RFC 1122. Requirements for Internet Hosts.
	RFC 1577. Classical IP over ATM.

Image 53

3Com 2500 manual References, Forwarding to Nodes within an LIS

Contents

Lanplex 2500 Extended Switching User Guide 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents Default Route Address Resolution Protocol ARP What Is Routing?Overlapped IP VLANs Example Pruning Mbone Multicast Routing Algorithms FloodingDvmrp Metric Value Elements IPX Routing Administering Routes Administering interfaces LIS InterfacesAbout Aarp Displaying Interfaces Displaying the ATM ARP Cache Deﬁning a Static Route10-2 10-3 11-2 Displaying Routes Displaying the Multicast Cache11-3 11-3 Modifying an Interface MIB Objects 13-4 Alarms What Is RMON?12-11 12-12 Support from 3Com A-4 Returning Products for Repair A-4 About this Guide When you conﬁgure your LANplex 2500 systemIntroduction Monitoring Rmon List conventions that are used throughout this guide ConventionsIcon Type Description Information Note Instructions LANplex 2500 Documentation 801-00322-000 LANplex 2500 Software Release Notes 2-5 , Module Installation Guides About this Guide Switching FeaturesAbout LANplex Extended Switching software Using Menus Bridge Menu Hierarchy IP Menu Hierarchy IPX Menu Hierarchy Appletalk Menu Hierarchy Vlans on For the network administratorAbout VLANs Vlan concept in LAN technology helps minimize broadcast Vlans on the Lanplex System Vlan Conﬁguration Protocol Suite SNA Services over Ethernet EthertypeEthertype, Snap PID DECnet Layer 3 Addressing Information Switch Ports About VLANs Index 1 2 Data received on VLAN, so the Default Vlan is usedIP port Source port Default None So the Default Vlan is usedData received on Is flooded on Because XNS port System 158.103.122.2 Data received on Is flooded on Because IP subnetOn port IP subnet 158.103.123.2 About VLANs Example of a Protocol-Sensitive Vlan Conﬁguration Vlan Examples Example A Vlan Conﬁguration with Servers on Separate 100BASE-T ports Example Vlans on the Lanplex System Lanplex System Bridging and Routing Subnetted Architecture with LANplex Switching Hubs Multiple Ports per Subnets with the LANplex 2500 System Routing Models Bridging Bridging in the Traditional Bridging and Routing Model Bridging in the LANplex Bridging and Routing Model Routing in the LANplex Bridging and Routing Model Bridging and Routing in the Lanplex System OSI Model Routing with IP TechnologyIP Routing Routing Elements of IPSection Hardware-conﬁgured 48-bit addresses Address Classes How a Subnet Mask Is Applied to the IP Address Shows the routing table of the router in Figure Static Routes Dynamic Routes Using RIP Example of an ARP Cache Example of ARP Cache Updated with ARP Reply Transmission Errors Classical IP over Routing with Forwarding to Nodes within an LIS References Routing with IP Technology Multicast Routing Routing with IP MulticastAbout IP Provider To a multicast routerTunnels on page 6 for more information about tunnels Multicast tunnel only if the Time-To-Live TTL value present Flooding Spanning Trees Reverse Path Forwarding Algorithms routing Shows a simple network with ﬁve links Simple Network Implemented Without Using Spanning Tree Which are described in this section MulticastInterfaces Routing with IP Multicast Environment IPX RoutingNetWare NetWare Protocols and the OSI Reference Model Be provided by protocols above IPX Protocol RIP Shows the IPX packet format How IPX Routing Works IPX Packet Routing How IPX Routing Works Intranetwork Service Advertising Protocol SAPElements Shows an example of a typical routing information table Aging Timer The time since the network’s last update Internetwork Service Information IPX Packet Format Routing with IPX Server Information Table Server Information Maintenance Elements of IPX Routing Routing with IPX About AppleTalk Routing in AN Appletalk EnvironmentAppleTalk Network Named Entities AppleTalk Networks and AppleTalk Zones Protocols AppleTalk Protocols and the OSI Reference Model Routing in AN Appletalk Environment AppleTalk Protocols Network Router Interface AppleTalk Protocols Description language used by many printers About AarpMapping for both extended and nonextended networks Another probe packet About Aarp Routing in AN Appletalk Environment Displaying Vlan Information Administering VlansFrom the top level of the Administration Console, enter Describes these statistics Example of a detailed display for the VLANsFields for Vlan Information Description Index Layer Deﬁning Vlan Information Vlan Modifying Vlan Information Enter the indexes for the VLANs you want to remove Example InformationRemoving Vlan Follow these steps to remove a Vlan deﬁnition Administering Vlans Administering Administering IP Routing Administering IP Routing Ip interface summary Ip interface detail Deﬁning an IP LIS Interface Example summary displayExample detail display LIS interface example with both PVCs and SVCs Atm Route Arp Detail Removing an Accept the default yes if you want to delete the interfaceModifying an Interface Removing an Advertisement Address Adding a Permanent Virtual Circuit PVC RoutesRemoving a Permanent Virtual Circuit PVC Automatically Interface Status Information Description Direct Static Route was statically configured LearnedTiming out Timed out Displaying Routing Table Flushing a Route Removing a Route Corresponding MAC addresses Default route is immediately removed from the routing tableARP Cache Example display of the contents of the ARP cache String from the top level of the Administration ConsoleDisplaying the ARP Cache ATM ARP Servers Administer the ATM ARP cacheFlushing the ARP Cache ARP cache entries are immediately removed from the table Removing an ATM ARP Server ATM switch, such as 3Com’s CELLplex 7000 system Ip atmArpServer arp Display Removing an ATM ARP Cache Entry UDP Helper Bootp including Dhcp = Time = DNS =Flushing the ATM Are modiﬁed and then forwarded through the router Displaying UDP Helper Information Enabling Disabling IP Routing Enabling Disabling Icmp Router Discovery Setting the RIPMode Operate in any of three modes You may receive one of the following responses Pinging an IP StationEnter the IP address of the station you want to ping Describes the IP statistics Displaying IP Statistics Administering IP Routing IP Multicast Routing Administering Enabling Enabling and Disabling DvmrpDisabling Igmp Methods to make this determination Administering IP Example multicast interface conﬁguration From the top level of the Administration Console, enterRate Limit Enabling Multicast Interfaces Disabling Multicast Interfaces Multicast Tunnels Multicast Tunnels Administration Console, enterIP address of the remote multicast router Displaying Tunnel is removed Deﬁning a To deﬁne an IP multicast tunnel Multicast TunnelRemoving a Multicast Tunnel Describes the ﬁelds in the route display Displaying Routes You are prompted for the multicast source address Displaying the Multicast Cache Following display shows the multicast cache conﬁguration Describes the ﬁelds in the cache display Administering IP Multicast Routing Administering IPX Routing Address. Each address within the network should be unique Deﬁne an associated interfaceFormats and two Fddi encapsulation formats. The Ethernet Is available for communications Up or unavailable Down Deﬁning an IPX From the Administration Console top-level menu, enter Ipx interface modify Known to the router Administration ConsoleRouters Segment. a tic is approximately 55 milliseconds Console top-level menu, enter As well as the routing tableDeﬁning a Static Route Ipx route remove Servers Server table using the Administration Console Deﬁning a Static Server Console top-level menu, enter Enter the number of hops to the server. Example From the Administration Console top-level menu, enterRemoving a Server To remove a server Flushing Servers Forwarding Setting IPX Enhanced RIP SettingFollow the IPX router implementation guidelines Brackets, press Return at the prompt Enter the SAP mode off, passive, or active. To use the value Setting the SAP Statistics Displaying Describers the IPX RIP statistics Example below SAP Requests Describes the IPX SAP statisticsSAP Entries Number of servers in the server table Been received Ipx statistics forwarding Describes the IPX forwarding statistics Layer header errors Hdr ErrorsErrors in network layer header No Routes Administering Appletalk Routing Associated AppleTalk interface Deﬁning an Interface Displaying AppleTalk Interfaces Removing an Interface Enter the zone name Appletalk route display Following example shows a routing table display 12-7 Following example shows an Aarp cache display Removing an Entry To remove an Aarp cache entry Cache Displaying the Zone Table Zone Table by Zones Enter enable or disable at the promptConﬁguring Forwarding Enter enable or disable at the checksum veriﬁcation prompt Enter enable or disable at the checksum generation promptConﬁguring Checksum Pinging an AppleTalk Node Describes the AppleTalk DDP statistics you can view Following is an example of DDP summary statistics Describes the Rtmp statistics you can view Displaying Rtmp InformationAn example of summary statistics is shown below Displaying ZIP Information Describes the ZIP statistics you can view Displaying NBP Information Describes the NBP statistics you can view Remote Monitoring Rmon Technology Remote Monitoring Rmon and the Lanplex System Remote Monitoring Rmon Technology Remote Monitoring Rmon Technology Variable and trigger an alarm AlarmSegment being monitored History Information Base Management Example of an Rmon MIB Counter Object Instances of when counters exceed their set threshold AlarmsApplication for details on setting up alarms You misleading results Manually Set Thresholds Generates an alarm only under the following conditions Appendix a Technical Support Appendix Variety of services. This appendix describes these services ServicesTechnical Support On-line Technical Press Return to see the 3ComForum Main menu Access by Digital Modem Support from Maintenance, application training, and support servicesYour Network Supplier Support contracts are available from 3Com U.S. and Canada, call 800 876-3266 for customer service3Com Numerics Index See also RIP See also SAP Mbone MIB See also Fddi station statistics Tunnels IP multicast 5-6