Gigabit Ethernet TCP/IP Error Recovery

Resolving The Problem

This document provides information on the error recovery path for Gigabit Ethernet running TCP/IP; it is different than on older interfaces.

Sometimes you will see an IP interface active and working, even though the Ethernet line description is in a status of RCYPND.

This is normal.

Answering message CPA57E9 (with G or R) will initiate recovery of the system objects and should not affect TCP/IP.

(You could also an IP interface active and working, even though the Ethernet line description is in a status of RCYCNL. )

To automate the answering of message CPA57E9, use the Work with Reply List Entries (WRKRPYLE).

The communications path used by TCP/IP for Gigabit Ethernet interfaces is different than older interfaces. Therefore, TCP/IP handles its recovery separately from the recovery processing for the system for the line, controller, and device objects. TCP/IP recovers when it is informed that the link is back up. The system recovery is driven by the CMNRCYLMT configured for the line. If those recovery limits are exceeded, recovery of the system objects waits for a response to an operator message without regard to the physical link status.

The system object recovery method for Gigabit is the same as for any other line and is not considered an error. In this case, forcing the TCP/IP recovery to wait for the system object recovery does not seem desirable. This is considered a permanent restriction.