diff --git a/usr.sbin/dhcp/client/scripts/netbsd b/usr.sbin/dhcp/client/scripts/netbsd
index 3c2f9ae8a1f3..4cb206b89e3b 100644
--- a/usr.sbin/dhcp/client/scripts/netbsd
+++ b/usr.sbin/dhcp/client/scripts/netbsd
@@ -1,230 +1,256 @@
 #!/bin/sh
 #
-# $NetBSD: netbsd,v 1.12 2001/04/02 23:45:54 mellon Exp $
+# $NetBSD: netbsd,v 1.13 2001/04/11 21:22:53 christos Exp $
+
+ENTERHOOKS=/etc/dhclient-enter-hooks
+EXITHOOKS=/etc/dhclient-exit-hooks
+RESOLV=/etc/resolv.conf
 
 make_resolv_conf() {
-  echo search $new_domain_name >/etc/resolv.conf
-  for nameserver in $new_domain_name_servers; do
-    echo nameserver $nameserver >>/etc/resolv.conf
-  done
+	echo search $new_domain_name > $RESOLV
+	for nameserver in $new_domain_name_servers; do
+		echo nameserver $nameserver >> $RESOLV
+	done
 }
 
 # Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
 exit_with_hooks() {
-  exit_status=$1
-  if [ -x /etc/dhclient-exit-hooks ]; then
-    . /etc/dhclient-exit-hooks
-  fi
-# probably should do something with exit status of the local script
-  exit $exit_status
+	exit_status=$1
+	if [ -x "$EXITHOOKS" ]; then
+		. "$EXITHOOKS"
+	fi
+	# probably should do something with exit status of the local script
+	exit $exit_status
+}
+
+
+add_new_routes() {
+	for router in $new_routers; do
+		route add default $router
+	done >/dev/null 2>&1
+
+	set -- $new_static_routes
+	while [ $# -gt 1 ]; do
+		route add $0 $1
+		shift; shift
+	done
+}
+
+delete_old_routes() {
+	for router in $old_routers; do
+		route delete default $router >/dev/null 2>&1
+	done
+	if [ ! -z "$old_static_routes" ]; then
+		set -- $old_static_routes
+		while [ $# -gt 1 ]; do
+			route delete $1 $2
+			shift; shift
+		done
+	fi
+	arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' | sh
 }
 
 # Invoke the local dhcp client enter hooks, if they exist.
-if [ -x /etc/dhclient-enter-hooks ]; then
-  exit_status=0
-  . /etc/dhclient-enter-hooks
-  # allow the local script to abort processing of this state
-  # local script must set exit_status variable to nonzero.
-  if [ $exit_status -ne 0 ]; then
-    exit $exit_status
-  fi
+if [ -x $ENTERHOOKS ]; then
+	exit_status=0
+	. $ENTERHOOKS
+	# allow the local script to abort processing of this state
+	# local script must set exit_status variable to nonzero.
+	if [ $exit_status -ne 0 ]; then
+		exit $exit_status
+	fi
 fi
 
-if [ x$new_host_name != x ]; then
-   echo New Host Name: $new_host_name
+if [ ! -z "$new_host_name" ]; then
+	echo New Host Name: $new_host_name
 fi
 
-if [ x$new_nis_domain != x ]; then
-   echo New NIS Domain: $new_nis_domain
+if [ ! -z "$new_nis_domain" ]; then
+	echo New NIS Domain: $new_nis_domain
 fi
 
-if [ x$new_network_number != x ]; then
-   echo New Network Number: $new_network_number
+if [ ! -z "$new_network_number" ]; then
+	echo New Network Number: $new_network_number
 fi
 
-if [ x$new_broadcast_address != x ]; then
- echo New Broadcast Address: $new_broadcast_address
-  new_broadcast_arg="broadcast $new_broadcast_address"
-fi
-if [ x$old_broadcast_address != x ]; then
-  old_broadcast_arg="broadcast $old_broadcast_address"
-fi
-if [ x$new_subnet_mask != x ]; then
-  new_netmask_arg="netmask $new_subnet_mask"
-fi
-if [ x$old_subnet_mask != x ]; then
-  old_netmask_arg="netmask $old_subnet_mask"
-fi
-if [ x$alias_subnet_mask != x ]; then
-  alias_subnet_arg="netmask $alias_subnet_mask"
+if [ ! -z "$new_broadcast_address" ]; then
+	echo New Broadcast Address: $new_broadcast_address
+	new_broadcast_arg="broadcast $new_broadcast_address"
 fi
 
-if [ x$reason = xMEDIUM ]; then
-  eval "ifconfig $interface $medium"
-  eval "ifconfig $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1
-  sleep 1
-  exit_with_hooks 0
+if [ ! -z "$old_broadcast_address" ]; then
+	old_broadcast_arg="broadcast $old_broadcast_address"
 fi
 
-if [ x$reason = xPREINIT ]; then
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
-  fi
-  ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \
-		broadcast 255.255.255.255 up
-  exit_with_hooks 0
+if [ ! -z "$new_subnet_mask" ]; then
+	new_netmask_arg="netmask $new_subnet_mask"
 fi
 
-if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
-  exit_with_hooks 0
+if [ ! -z "$old_subnet_mask" ]; then
+	old_netmask_arg="netmask $old_subnet_mask"
 fi
-  
-if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
-   [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
-  if type domainname > /dev/null 2>&1; then
-    if [ x$new_nis_domain != x ]; then
-      domainname $new_nis_domain
-    fi
-  fi
-  if type hostname > /dev/null 2>&1; then
-    current_hostname=`hostname`
-    if [ x$current_hostname = x ] || \
-       [ x$current_hostname = x$old_host_name ]; then
-      if [ x$current_hostname = x ] || \
-         [ x$new_host_name != x$old_host_name ]; then
-        hostname $new_host_name
-      fi
-    fi
-  fi
+
+if [ ! -z "$alias_subnet_mask" ]; then
+	alias_subnet_arg="netmask $alias_subnet_mask"
+fi
+
+case "$reason" in
+MEDIUM)
+	eval "ifconfig $interface $medium"
+	eval "ifconfig $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1
+
+	sleep 1
+
+	exit_with_hooks 0
+	;;
+
+PREINIT)
+	if [ ! -z "$alias_ip_address" ]; then
+		ifconfig $interface inet \
+		    -alias $alias_ip_address >/dev/null 2>&1
+		route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+	fi
+
+	ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \
+	    broadcast 255.255.255.255 up
+
+	exit_with_hooks 0
+	;;
+
+ARPCHECK|ARPSEND)
+	exit_with_hooks 0
+	;;
+
+BOUND|RENEW|REBIND|REBOOT)
+	if [ ! -z "$new_nis_domain" ]; then
+		if type domainname > /dev/null 2>&1; then
+			domainname $new_nis_domain
+		fi
+	fi
+
+	if type hostname > /dev/null 2>&1; then
+		if [ \( -z "$current_hostname" \) -o \
+		    \( "x$new_host_name" = "x$old_hostname" \) ]; then
+			current_hostname=`hostname`
+		fi
+		if [ \( -z $current_hostname \) -o \
+		    \( "x$new_host_name" != "x$old_hostname" \) ]; then
+			hostname $new_host_name
+		fi
+	fi
     
-  if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
-		[ x$alias_ip_address != x$old_ip_address ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
-  fi
-  if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]
-   then
-    eval "ifconfig $interface inet -alias $old_ip_address $medium"
-    route delete $old_ip_address 127.1 >/dev/null 2>&1
-    for router in $old_routers; do
-      route delete default $router >/dev/null 2>&1
-    done
-    if [ "$old_static_routes" != "" ]; then
-      set $old_static_routes
-      while [ $# -gt 1 ]; do
-	route delete $1 $2
-	shift; shift
-      done
-    fi
-    arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' |sh
-  fi
-  if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
-     [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
-    eval "ifconfig $interface inet $new_ip_address $new_netmask_arg \
-					$new_broadcast_arg $medium"
-    route add $new_ip_address 127.1 >/dev/null 2>&1
-    for router in $new_routers; do
-      route add default $router >/dev/null 2>&1
-    done
-    if [ "$new_static_routes" != "" ]; then
-      set $new_static_routes
-      while [ $# -gt 1 ]; do
-	route add $1 $2
-	shift; shift
-      done
-    fi
-  fi
-  if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
-   then
-    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
-    route add $alias_ip_address 127.0.0.1
-  fi
-  make_resolv_conf
-  exit_with_hooks 0
-fi
+	if [ \( ! -z "$old_ip_address" \) -a \( ! -z "$alias_ip_address" \) -a \
+	    \( "x$alias_ip_address" != "x$old_ip_address" \) ]; then
+		ifconfig $interface inet \
+		    -alias $alias_ip_address > /dev/null 2>&1
+		route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+	fi
 
-if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ]; then
-  if [ x$old_nis_domain != x ]; then
-    # delete the old nis domain name
-    domainname ""
-  fi
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
-  fi
-  if [ x$old_ip_address != x ]; then
-    eval "ifconfig $interface inet -alias $old_ip_address $medium"
-    route delete $old_ip_address 127.1 >/dev/null 2>&1
-    for router in $old_routers; do
-      route delete default $router >/dev/null 2>&1
-    done
-    if [ "$old_static_routes" != "" ]; then
-      set $old_static_routes
-      while [ $# -gt 1 ]; do
-	route delete $1 $2
-	shift; shift
-      done
-    fi
-    arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' \
-						|sh >/dev/null 2>&1
-  fi
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
-    route add $alias_ip_address 127.0.0.1
-  fi
-  exit_with_hooks 0
-fi
+	if [ \( ! -z "$old_ip_address" \) -a \
+	    \( "x$old_ip_address" != "x$new_ip_address" \) ]; then
+		eval "ifconfig $interface inet -alias $old_ip_address $medium"
+		route delete $old_ip_address 127.0.0.1 >/dev/null 2>&1
 
-if [ x$reason = xTIMEOUT ]; then
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
-  fi
-  if [ x$new_host_name != x ]; then
-    hostname $new_host_name
-  fi
-  if [ x$new_nis_domain != x ]; then
-    domainname $new_nis_domain
-  fi
-  eval "ifconfig $interface inet $new_ip_address $new_netmask_arg \
-					$new_broadcast_arg $medium"
-  sleep 1
-  if [ "$new_routers" != "" ]; then
-    set $new_routers
-    if ping -n -q -c 1 -w 1 $1; then
-      if [ x$new_ip_address != x$alias_ip_address ] && \
-			[ x$alias_ip_address != x ]; then
-	ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
-	route add $alias_ip_address 127.0.0.1
-      fi
-      route add $new_ip_address 127.1 >/dev/null 2>&1
-      for router in $new_routers; do
-	route add default $router >/dev/null 2>&1
-      done
-      set $new_static_routes
-      while [ $# -gt 1 ]; do
-	route add $0 $1
-	shift; shift
-      done
-      make_resolv_conf
-      exit_with_hooks 0
-    fi
-  fi
-  eval "ifconfig $interface inet -alias $new_ip_address $medium"
-  for router in $old_routers; do
-    route delete default $router >/dev/null 2>&1
-  done
-  if [ "$old_static_routes" != "" ]; then
-    set $old_static_routes
-    while [ $# -gt 1 ]; do
-      route delete $1 $2
-      shift; shift
-    done
-  fi
-  arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' \
-							|sh >/dev/null 2>&1
-  exit_with_hooks 1
-fi
+		delete_old_routes
+	fi
 
-exit_with_hooks 0
+	if [ \( -z "$old_ip_address" \) -o \
+	    \( "x$old_ip_address" != "x$new_ip_address" \) -o \
+	    \( "x$reason" = "xBOUND" \) -o \( "x$reason" = "xREBOOT" \) ]; then
+		eval "ifconfig $interface inet $new_ip_address \
+		    $new_netmask_arg $new_broadcast_arg $medium"
+		route add $new_ip_address 127.0.0.1 >/dev/null 2>&1
+
+		add_new_routes
+	fi
+
+	if [ \( ! -z "$alias_ip_address" \) -a \
+	    \( "x$new_ip_address" != "x$alias_ip_address" \) ]; then
+		ifconfig $interface inet alias $alias_ip_address \
+		    $alias_subnet_arg
+		route add $alias_ip_address 127.0.0.1
+	fi
+	make_resolv_conf
+	exit_with_hooks 0
+	;;
+
+EXPIRE|FAIL)
+	if [ ! -z "$old_nis_domain" ]; then
+		if type domainname > /dev/null 2>&1; then
+			# delete the old nis domain name
+			domainname ""
+		fi
+	fi
+
+	if [ ! -z "$alias_ip_address" ]; then
+		ifconfig $interface inet -alias $alias_ip_address 
+		route delete $alias_ip_address 127.0.0.1
+	fi > /dev/null 2>&1
+
+	if [ ! -z "$old_ip_address" ]; then
+		eval "ifconfig $interface inet -alias $old_ip_address $medium"
+		route delete $old_ip_address 127.0.0.1 >/dev/null 2>&1
+		delete_old_routes
+
+	fi
+
+	if [ ! -z "$alias_ip_address" ]; then
+		ifconfig $interface inet alias $alias_ip_address \
+		    $alias_subnet_arg
+		route add $alias_ip_address 127.0.0.1
+	fi
+
+	exit_with_hooks 0
+	;;
+
+TIMEOUT)
+	if [ ! -z "$alias_ip_address" ]; then
+		ifconfig $interface inet -alias $alias_ip_address
+		route delete $alias_ip_address 127.0.0.1
+	fi > /dev/null 2>&1
+
+	if [ ! -z "$new_host_name" ]; then
+		if type hostname > /dev/null 2>&1; then
+			hostname $new_host_name
+		fi
+	fi
+
+	if [ ! -z "$new_nis_domain" ]; then
+		if type domainname > /dev/null 2>&1; then
+			domainname $new_nis_domain
+		fi
+	fi
+
+	eval "ifconfig $interface inet $new_ip_address $new_netmask_arg \
+	    $new_broadcast_arg $medium"
+	sleep 1
+
+	if [ ! -z "$new_routers" ]; then
+		set -- $new_routers
+		if ping -n -q -c 1 -w 1 $1; then
+			if [ \( ! -z "$alias_ip_address" \) -a \
+			    \( "x$new_ip_address" != "x$alias_ip_address" \) ]
+			then
+				ifconfig $interface inet alias \
+				    $alias_ip_address $alias_subnet_arg
+				route add $alias_ip_address 127.0.0.1
+			fi
+
+			route add $new_ip_address 127.0.0.1 >/dev/null 2>&1
+
+			add_new_routes
+			make_resolv_conf
+			exit_with_hooks 0
+		fi
+	fi
+
+	eval "ifconfig $interface inet -alias $new_ip_address $medium"
+
+	delete_old_routes
+
+	exit_with_hooks 1
+	;;
+*)
+	exit_with_hooks 0
+	;;
+esac