Displaying the ARP, Removing an ARP Cache Entry | 3Com 2500 specs

9-14 CHAPTER 9: ADMINISTERING IP ROUTING

Displaying the ARP						You can display the contents of the ARP cache for your system.
			Cache			To display the contents of the ARP cache, enter the following command
Top-Level Menu
Top-Level Menu						string from the top level of the Administration Console:
system						string from the top level of the Administration Console:
ethernet	interface					ip arp	display
fddi	route					ip arp	display
atm	➧arp		➧display
bridge	atmArpServer		remove
➧ip	atmArpServer		remove
➧ip	multicast		flush
ipx	udpHelper					Example display of the contents of the ARP cache:
appletalk	routing					Example display of the contents of the ARP cache:
snmp	icmpRouterDiscovery
analyzer	rip			IP routing is enabled, RIP is active,
script	ping			IP routing is enabled, RIP is active,
script	ping			ICMP router discovery is disabled
logout	statistic s			ICMP router discovery is disabled
				IP address			I/F	Hardware address	Circuit
			158.101.112.2				1	00-40-0b-40-64-e6	-/-
			158.101.112.7				1	08-00-20-76-a2-f2	-/-
			158.101.116.7				2	00-80-3e-02-68-00	-/-
			158.101.112.14				1	08-00-09-4e-24-20	-/-
			158.101.116.16				2	00-80-3e-02-8e-6a	-/-
			158.101.116.17				2	00-80-3e-02-8e-7f	-/-
			158.101.116.18				2	00-80-3e-02-8e-94	-/-
			158.101.112.22				1	08-00-20-04-d1-5e	-/-
			158.101.116.19				2	00-80-3e-02-8e-2b	-/-
			158.101.112.28				1	08-00-09-8c-de-3a	-/-
			158.101.112.29				1	08-00-09-82-d8-1b	-/-
			158.101.116.27				2	00-80-3e-1d-75-00	-/-

Removing an ARP

		Cache Entry
Top-Level Menu
system
ethernet	interface
fddi	route
atm	➧arp		display
bridge	atmArpServer		➧remove
➧ip	multicast		flush
ipx	udpHelper
appletalk	routing
snmp	icmpRouterDiscovery
analyzer	rip
script	ping
logout	statistics

You might want to remove an entry from the ARP cache if the MAC address has changed. To remove an entry from the ARP cache:

1From the top level of the Administration Console, enter:

ip arp remove

2Enter the IP address you want to remove.

The address is immediately removed from the table. If necessary, the system subsequently uses ARP to ﬁnd the new MAC address corresponding to that IP address.

Image 108

3Com 2500 Displaying the ARP, String from the top level of the Administration Console, Removing an ARP Cache Entry

Contents

Lanplex 2500 Extended Switching User Guide 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents What Is Routing? Default Route Address Resolution Protocol ARPOverlapped IP VLANs Example Mbone Multicast Routing Algorithms Flooding PruningDvmrp Metric Value Elements IPX Routing Administering interfaces LIS Interfaces Administering RoutesAbout Aarp Displaying Interfaces Deﬁning a Static Route Displaying the ATM ARP Cache10-2 10-3 Displaying Routes Displaying the Multicast Cache 11-211-3 11-3 Modifying an Interface What Is RMON? MIB Objects 13-4 Alarms12-11 12-12 Support from 3Com A-4 Returning Products for Repair A-4 When you conﬁgure your LANplex 2500 system About this GuideIntroduction Monitoring Rmon Conventions List conventions that are used throughout this guideIcon Type Description Information Note Instructions LANplex 2500 Documentation LANplex 2500 Software Release Notes 801-00322-000 Module Installation Guides 2-5 , About this Guide Features SwitchingAbout LANplex Extended Using Menus Switching software Bridge Menu Hierarchy IP Menu Hierarchy IPX Menu Hierarchy Appletalk Menu Hierarchy For the network administrator Vlans onAbout VLANs Vlan concept in LAN technology helps minimize broadcast Vlans on the Lanplex System SNA Services over Ethernet Ethertype Vlan Conﬁguration Protocol SuiteEthertype, Snap PID DECnet Switch Ports Layer 3 Addressing Information About VLANs VLAN, so the Default Vlan is used Index 1 2 Data received onIP port Source port So the Default Vlan is used Default NoneData received on Is flooded on Because XNS port System Data received on Is flooded on Because IP subnet 158.103.122.2On port IP subnet 158.103.123.2 About VLANs Vlan Examples Example Example of a Protocol-Sensitive Vlan Conﬁguration Example A Vlan Conﬁguration with Servers on Separate 100BASE-T ports Vlans on the Lanplex System Bridging and Routing Lanplex System Subnetted Architecture with LANplex Switching Hubs Multiple Ports per Subnets with the LANplex 2500 System Bridging Routing Models 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 Routing with IP Technology IP RoutingOSI Model Elements of IP RoutingSection 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 Dynamic Routes Using RIP Static Routes Example of an ARP Cache Example of ARP Cache Updated with ARP Reply Errors Transmission Routing with Classical IP over References Forwarding to Nodes within an LIS Routing with IP Technology Routing with IP Multicast About IPMulticast Routing To a multicast router ProviderTunnels on page 6 for more information about tunnels Multicast tunnel only if the Time-To-Live TTL value present Algorithms routing Flooding Spanning Trees Reverse Path Forwarding Simple Network Implemented Without Using Spanning Tree Shows a simple network with ﬁve links Multicast InterfacesWhich are described in this section Routing with IP Multicast IPX Routing NetWareEnvironment Be provided by protocols above IPX NetWare Protocols and the OSI Reference Model Protocol RIP Shows the IPX packet format How IPX Routing Works IPX Packet Routing How IPX Routing Works Service Advertising Protocol SAP ElementsIntranetwork Aging Timer The time since the network’s last update Shows an example of a typical routing information table Internetwork Service Information IPX Packet Format Routing with IPX Server Information Table Server Information Maintenance Elements of IPX Routing Routing with IPX Routing in AN Appletalk Environment About AppleTalkAppleTalk 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 About Aarp Description language used by many printersMapping for both extended and nonextended networks Another probe packet About Aarp Routing in AN Appletalk Environment Administering Vlans From the top level of the Administration Console, enterDisplaying Vlan Information Example of a detailed display for the VLANs Describes these statisticsFields for Vlan Information Description Index Layer Deﬁning Vlan Information Modifying Vlan Information Vlan Information Removing Vlan Follow these steps to remove a Vlan deﬁnitionEnter the indexes for the VLANs you want to remove Example Administering Vlans Administering IP Routing Administering Administering IP Routing Ip interface summary Ip interface detail Example summary display Example detail displayDeﬁning an IP LIS Interface LIS interface example with both PVCs and SVCs Atm Route Arp Detail Accept the default yes if you want to delete the interface Modifying an InterfaceRemoving an Removing an Advertisement Address Routes Adding a Permanent Virtual Circuit PVCRemoving a Permanent Virtual Circuit PVC Automatically Static Route was statically configured Learned Interface Status Information Description DirectTiming out Timed out Displaying Routing Table Removing a Route Flushing a Route Default route is immediately removed from the routing table ARP CacheCorresponding MAC addresses String from the top level of the Administration Console Example display of the contents of the ARP cacheDisplaying the ARP Cache Administer the ATM ARP cache ATM ARP ServersFlushing the ARP Cache ARP cache entries are immediately removed from the table ATM switch, such as 3Com’s CELLplex 7000 system Removing an ATM ARP Server Removing an ATM ARP Cache Entry Ip atmArpServer arp Display Bootp including Dhcp = Time = DNS = UDP HelperFlushing the ATM Are modiﬁed and then forwarded through the router Displaying UDP Helper Information Enabling Disabling IP Routing Setting the RIP Enabling Disabling Icmp Router DiscoveryMode Operate in any of three modes Pinging an IP Station Enter the IP address of the station you want to pingYou may receive one of the following responses Displaying IP Statistics Describes the IP statistics Administering IP Routing Administering IP Multicast Routing Enabling and Disabling Dvmrp EnablingDisabling Igmp Methods to make this determination Administering IP From the top level of the Administration Console, enter Rate LimitExample multicast interface conﬁguration Disabling Multicast Interfaces Enabling Multicast Interfaces Multicast Tunnels Administration Console, enter Multicast TunnelsIP address of the remote multicast router Displaying Deﬁning a To deﬁne an IP multicast tunnel Multicast Tunnel Removing a Multicast TunnelTunnel is removed Displaying Routes Describes the ﬁelds in the route display Displaying the Multicast Cache You are prompted for the multicast source address Following display shows the multicast cache conﬁguration Describes the ﬁelds in the cache display Administering IP Multicast Routing Administering IPX Routing Deﬁne an associated interface Address. Each address within the network should be uniqueFormats and two Fddi encapsulation formats. The Ethernet Is available for communications Up or unavailable Down From the Administration Console top-level menu, enter Deﬁning an IPX Ipx interface modify Administration Console Known to the routerRouters Segment. a tic is approximately 55 milliseconds As well as the routing table Deﬁning a Static RouteConsole top-level menu, enter Ipx route remove Server table using the Administration Console Servers Console top-level menu, enter Deﬁning a Static Server From the Administration Console top-level menu, enter Enter the number of hops to the server. ExampleRemoving a Server To remove a server Flushing Servers Setting IPX Forwarding Setting Enhanced RIPFollow the IPX router implementation guidelines Brackets, press Return at the prompt Setting the SAP Enter the SAP mode off, passive, or active. To use the value Displaying Statistics Example below Describers the IPX RIP statistics Describes the IPX SAP statistics SAP RequestsSAP Entries Number of servers in the server table Been received Describes the IPX forwarding statistics Ipx statistics forwarding Hdr Errors Layer header errorsErrors in network layer header No Routes Administering Appletalk Routing Associated AppleTalk interface Displaying AppleTalk Interfaces Deﬁning an Interface Enter the zone name Removing an Interface 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 Enter enable or disable at the prompt Conﬁguring ForwardingZone Table by Zones Enter enable or disable at the checksum generation prompt Enter enable or disable at the checksum veriﬁcation promptConﬁguring Checksum Pinging an AppleTalk Node Following is an example of DDP summary statistics Describes the AppleTalk DDP statistics you can view Displaying Rtmp Information An example of summary statistics is shown belowDescribes the Rtmp statistics you can view Displaying ZIP Information Describes the ZIP statistics you can view Displaying NBP Information Describes the NBP statistics you can view Remote Monitoring Rmon and the Lanplex System Remote Monitoring Rmon Technology Remote Monitoring Rmon Technology Remote Monitoring Rmon Technology Alarm Variable and trigger an alarmSegment being monitored History Management Information Base Example of an Rmon MIB Counter Object Alarms Instances of when counters exceed their set thresholdApplication for details on setting up alarms You misleading results Manually Set Thresholds Generates an alarm only under the following conditions Appendix Appendix a Technical Support Services Variety of services. This appendix describes these servicesTechnical Support On-line Technical Access by Digital Modem Press Return to see the 3ComForum Main menu Maintenance, application training, and support services Support fromYour Network Supplier U.S. and Canada, call 800 876-3266 for customer service 3ComSupport contracts are available from 3Com Index Numerics See also RIP See also SAP Mbone MIB See also Fddi station statistics Tunnels IP multicast 5-6