Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

USER’S GUIDE472 CyberSWITCHP ROXY ARPUse the following graphic to help you in verifying that Proxy ARP is operational. When followingthe verification steps, substitute your addresses for the addresses used in the example.1. Create two Ethernet LANs connected across the WAN with a CyberSWITCH and a secondCabletron platform (for example, another CyberSWITCH product) properly configured. Thetwo Ethernet segments should be subnets of the same IP network. All IP host devices on theEthernet segments (except the CyberSWITCH and the other Cabletron platform) should beconfigured with the natural subnet mask so that both Ethernet segments look like one IPnetwork to all the IP host devices on the segments.2. Try to have an IP host device on one Ethernet segment communicate with an IP host device onthe other Ethernet segment. For example, ping from Host A to Host B.3. If the communication between two IP devices across the WAN is successfully established, thenthe proxy ARP feature is properly working.4. If the communication can NOT be established, display the ARP cache on the IP host devices tosee what MAC addresses are mapped to the target IP address. On many operating systems, thearp -a command displays the ARP cache. If the target IP addresses are mapped into thenearest CyberSWITCH’s MAC addresses respectively, for example, on Host A, Host B’s IPaddress is mapped to the CyberSWITCH A’s MAC address, then the proxy ARP feature isworking properly, but basic IP routing may not be operational. Establish the basic IPconnectivity first, then try to use the proxy ARP feature. If the target IP addresses are not shown(or are mapped to MAC addresses that are not displayed), try the following:a. On both CyberSWITCH platforms, issue theipnetif manage mode command to makesure that the proxy ARP feature is enabled for the LAN interface. If it is not enabled on oneor both of the CyberSWITCH platforms, enable it through the CFGEDIT configurationutility. Note that you have to restart the system for the changes to be effective.b. On both platforms, issue theipnetif manage mode command to make sure the LANinterfaces are configured with the proper subnet mask. Configure these platforms with theproper subnet masks, not the natural masks.ISDNCSX5500"Site1" CSX1200"Site2"Host A: 128.168.1.2 Host B: 128.168.2.2128.168.1.x 128.168.2.xWORKGROUP REMOTE ACCESS SWITCHLAN10BASE-TRXTXSERVICE CH-2D-CHCH-1SYNCPOWERLINE1CH-2D-CHCH-1SYNCLINE2CH-2D-CHCH-1SYNCLINE3CH-2D-CHAGICH-1SYNCLINE4