Not able to PING printer by Host Name after changing the Printer IP Address

Resolving The Problem

This document discusses an issue where you are unable to PING a printer from the IBM i system using a host name after changing the IP address in the printer or print server hardware. This typically occurs when the ARP cache on the system has been unable to "timeout" old information and replace it with new information. This happens when a writer on the iSeries is constantly attempting to write to the printer. The constant communication does not allow the system to clear the ARP cache entry, so the writer will continue to try sending data to the IP address of the printer.

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Allowing the System to Automatically Clear the ARP Cache

One way to resolve this situation is to end the writer and any other communications to this printer. You should run the following Change TCP/IP Attributes (CHGTCPA) command to set the ARP cache timeout (ARPTIMO) parameter to 15 minutes:

CHGTCPA ARPTIMO(15)

If the writer is not started for 15 minutes, the ARP cache should automatically be cleared, allowing the system to find the new MAC address or IP address for the printer.

Note: Allow 15 to 20 minutes for any network hardware to clear cached data regarding the printer. Then, attempt the PING or start the writer again. The reason this typically arises is because the writer is never ended, and the constant flow of data does not allow for the System i ARP cache to ever time out.


Manually Clearing the ARP Cache using System i Navigator

Another way to resolve this situation is to manually clear the ARP cache using System i Navigator.

In System i Navigator, do the following:

1.	Launch System i Navigator and click on the "+" sign for the IBM i system.
2.	Click on Network > TCP/IP Configuration > IPv4 > Interfaces.
3.	Right-click on the TCP/IP interfaces on the same TCP/IP subnet as the failing printer, and select ARP from the context or pop-up menu.
4.	All known TCP/IP addresses and their associated MAC addresses can be seen. Highlight the TCP/IP address of the printer, and choose Delete Entry.
5.	Attempt to PING the printer. The System i system will re-ARP, and should receive any new changed information for the printer.

Note: For more information on clearing the ARP cache using System i Navigator, refer to the following document:

N1015699, Clearing a Specific ARP Cache Entry: