Cabletron Systems CSX1000, CSX1200 manual Proxy ARP Operation

USER’S GUIDE

2.Make sure that the maximum addresses to obtain for the interface is non-zero.

3.Make sure that the number of addresses to pre-fetchfor the interface is non-zero.

4.The DHCP Server must be configured to distribute addresses to clients on the DHCP Client’s subnetwork.

Problem:

The DHCP Proxy Client is enabled, and it has opened its UDP port, but there aren’t any “DHCP- obtained” addresses in the IP Address Pool.

Action:

1.Check the DHCP-related configuration for WAN and WAN (Direct Host) IP network interfaces which should have IP addresses obtained from DHCP servers for them. Use CFGEDIT, or use the ipnetif command from Manage Mode. Correct if necessary.

2.Make sure that the LAN port to reach the DHCP server on for the interface is correct.

3.If the DHCP server is on a directly-connected LAN, you should be able to ping it successfully from the CyberSWITCH. If you cannot, check the LAN port IP configuration; make sure the DHCP server is operational.

4.If the DHCP server is not on the directly-connected LAN, a DHCP Relay Agent must be. A relay agent is required in order to successfully forward DHCP packets to a DHCP server on a different sub-network.

5.Assuming that a DHCP Relay Agent is present on the directly-connected LAN, you can attempt to ping the DHCP server. This may require the addition of IP static routes on both the CyberSWITCH and the DHCP server. These static routes are required for smooth operation of the DHCP protocol.

6.If the DHCP server is not on a directly-connected LAN, another test may be performed. If at all feasible, place a DHCP client workstation on the same LAN with the server. See if this DHCP client can obtain an IP address from the DHCP server.

PROXY ARP OPERATION

Problem:

Two IP hosts devices on different subnets in an IP network are unable to communicate across the WAN.

Action:

1.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.

2.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.

416 CyberSWITCH