Ported from an original script written for Solaris 2.6 Provides basic failover between two network interfaces on your IRIX host

if_check.ksh

#!/bin/sh
#
# See http://www.gaeltd.com/scripts-and-tools/ for more details
#
# 2004-09-14 Tom Kranz <tom@siliconbunny.com>
#
# Ported from an original script written for Solaris 2.6
# Provides basic failover between two network interfaces on your IRIX host
#
# Pre-reqs:
#	- you have two ethernet interfaces which use seperate switches
#	- you have a redundant network point (ie. a default router)
#
# Setup:
#	- configure your two ethernet interfaces with the same IP, but
#	make sure only one is up
#	- run this script from cron
#		- cron interval dictates how long you want the host down for
#	- the script will work out which interface is up and which is down
#
# Error codes:
# 0 - network connectivity is OK
# 1 - something's fubar on the network, and we've had to swap interfaces
# 2 - you didn't enter a IP address to ping to test connectivity - we'll
#     print a nice error message and then leave

# Static vars
PING=/usr/etc/ping
IFCONFIG=/usr/sbin/ifconfig

# Have you specified an IP to test against?
if [ $# -ne 1 ]
then
	echo
	echo "Usage: if_checker.sh <IP_address_to_ping>"
	echo
	echo "Where <IP_address_to_ping> is an always-reachable address you can"
	echo "use to verify connectivity"
	echo
	exit 2
fi

# Do the actual test
if $PING $1
then
	echo "Woohoo!"
	exit 0
else
	UPIF="`$IFCONFIG -a | grep -v LOOPBACK | grep UP | cut -b 1-4`"
	$DOWNIF="`$IFCONFIG -a | grep -v LOOPBACK | grep -v UP | grep RUNNING | cut -b 1-4`"
	$IFCONFIG $UPIF down
	$IFCONFIG $DOWNIF up

fi

# Another final ping check to see if the new interface is OK
$PING $1

exit 1