Knowledgebase

Issue:

Cannot ping or telnet to Iolan+ after creating ARP entry.

Cause:

1. Unit already has a preconfigured IP Address
2. Iolan+ has recieved an IP Address from a BootP server.
3. Mismatch of the Ethernet (MAC) address.

Solution:

By default the Iolan+ will broadcast a BootP request to obtain an IP Address if there is none configured. Verify with your BootP server if an IP Address has been allocated to the unit.

Note: Windows 2000 and server 2003 DHCP service also supports BootP requests if enabled.

Ensure that the Ethernet (MAC) address used in the "arp -s" command matches the Ethernet address printed on the bottom of the unit.
Use "arp" or "arp -a" to display the workstation's ARP table.

In some cases the MAC address may not have been properly set or has been changed so it does not match the Ethernet Address printed on the unit.
There are two methods of editing the MAC address:
1. Bootstrap menu - Reset option
2. Server Configuration screen

In both cases you will need to attach a terminal to the RJ45 serial Port of the Iolan+ to obtain these screens.

1. The bootstrap menu can be accessed through Port 1 (9600 8 N 1 No Flow Control) by typing [Control] + "b" 5-7 times while the unit is boot up.
You will be presented with the Bootstrap menu and choose the Reset option then Ethernet Address.
Enter in the Ethernet Address as it appears on the bottom of the unit.
Then quit and reboot.

Note: you can also configure the IP Address from the Bootstrap Reset menu

2. If you log into the Iolan+ and get to the Server Configuration you can change the MAC address (see the link below for details).

Related Articles:
1.) Setting an ethernet MAC address in the IOLAN+ serial server.
2.) RS422 to RS232 cable converter

1.) 

Cabling pinout diagrams