Xerox 4500 ps eth instruction manual Keepalive support for AIX, AIX Keepalive support

PSF/AIX Printing Using TCP/IP

Xerox 4500 PS ETH, Inst. & Operator's Guide

18.2 KEEPALIVE support for AIX

The TCP/IP components in AIX offer network attachment for printers. However, these TCPIP components do not always detect connection failures if a point-to-point session between the AIX machine and the device has failed (e.g. in connection with a printer being abruptly powered off). This may result in serious problems for IPDS printers in sessions with PSF/AIX

Now, support for the TCP KEEPALIVE facility has been added to the TCP/IP components of AIX to detect all communication failures. PSF/AIX directs TCP to send a KEEPALIVE transmission on a TCP connection remaining inactive for an extended period. If the KEEPALIVE transmission is not acknowledged, the TCP assumes that the connection partner has been lost and subsequently reports a failure to PSF/AIX

The frequency of these transmissions depends upon the configuration of AIX TCP/IP environment. The default for AIX is two hours or more. This, however, can be adjusted. These values apply to all TCP applications that request KEEPALIVE transmissions.

In the following, you are provided with instructions for using the KEEPALIVE support facility added to the TCP/IP components for AIX

18.3 AIX KEEPALIVE support

The "no" (network options) command can be used by the root user to configure KEEPALIVE frequencies.

no -o tcp_keepidle=nnn

no -o tcp_keepintvl=nnn

where nnn is in half-seconds.

The command “tcp_keepidle” specifies the interval of inactivity causing the TCP to generate a KEEPALIVE transmission for an application that requests them.

The default is 14400 (2 hours).

The command “tcp_keepintvl” specifies the interval between the nine retry attempts if a KEEPALIVE transmission is not acknowledged. The default is 150 (75 seconds).

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