Enterasys Networks CSX6000 - Manual (Page 472)

USER’S GUIDE
472 CyberSWITCH
P
ROXY
ARP
Use the following graphic to help you in verifying that Proxy ARP is operational. When following
the 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 second
Cabletron platform (for example, another CyberSWITCH product) properly configured. The
two Ethernet segments should be subnets of the same IP network. All IP host devices on the
Ethernet segments (except the CyberSWITCH and the other Cabletron platform) should be
configured with the natural subnet mask so that both Ethernet segments look like one IP
network 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 on
the 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, then
the proxy ARP feature is properly working.
4. If the communication can NOT be established, display the ARP cache on the IP host devices to
see what MAC addresses are mapped to the target IP address. On many operating systems, the
arp -a command displays the ARP cache. If the target IP addresses are mapped into the
nearest CyberSWITCH’s MAC addresses respectively, for example, on Host A, Host B’s IP
address is mapped to the CyberSWITCH A’s MAC address, then the proxy ARP feature is
working properly, but basic IP routing may not be operational. Establish the basic IP
connectivity 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 the ipnetif manage mode command to make
sure that the proxy ARP feature is enabled for the LAN interface. If it is not enabled on one
or both of the CyberSWITCH platforms, enable it through the CFGEDIT configuration
utility. Note that you have to restart the system for the changes to be effective.
b. On both platforms, issue the ipnetif manage mode command to make sure the LAN
interfaces are configured with the proper subnet mask. Configure these platforms with the
proper subnet masks, not the natural masks.
ISDN
CSX5500
"Site1"
CSX1200
"Site2"
Host A: 128.168.1.2 Host B: 128.168.2.2
128.168.1.x 128.168.2.x
WORKGROUP REMOTE ACCESS SWITCH
LAN 10BASE-T RX TX SERVICE CH-2 D-CH CH-1 SYNC POWER LINE 1 CH-2 D-CH CH-1 SYNC
LINE 2 CH-2 D-CH CH-1 SYNC
LINE 3 CH-2 D-CH AGI
CH-1 SYNC
LINE 4