Index: etc/network.subr
===================================================================
--- etc/network.subr	(revision 255712)
+++ etc/network.subr	(working copy)
@@ -1027,9 +1027,8 @@ ifalias_af_common()
 	_action=$3
 
 	# ifconfig_IF_aliasN which starts with $_af
-	alias=0
-	while : ; do
-		ifconfig_args=`get_if_var $_if ifconfig_IF_alias${alias}`
+	for alias in `list_vars ifconfig_${_if}_alias[0-9]\*`; do
+		eval ifconfig_args=\"\$$alias\"
 		_iaf=
 		case $ifconfig_args in
 		inet\ *)	_iaf=inet ;;
@@ -1051,15 +1050,13 @@ ifalias_af_common()
 			warn "\$ifconfig_${_if}_alias${alias} needs " \
 			    "\"inet\" keyword for an IPv4 address."
 		esac
-		alias=$(($alias + 1))
 	done
 
 	# backward compatibility: ipv6_ifconfig_IF_aliasN.
 	case $_af in
 	inet6)
-		alias=0
-		while : ; do
-			ifconfig_args=`get_if_var $_if ipv6_ifconfig_IF_alias${alias}`
+		for alias in `list_vars ipv6_ifconfig_${_if}_alias[0-9]\*`; do
+			eval ifconfig_args=\"\$$alias\"
 			case ${_action}:"${ifconfig_args}" in
 			*:"")
 				break
@@ -1071,7 +1068,6 @@ ifalias_af_common()
 				    "instead."
 			;;
 			esac
-			alias=$(($alias + 1))
 		done
 	esac
 
Index: etc/rc.subr
===================================================================
--- etc/rc.subr	(revision 255712)
+++ etc/rc.subr	(working copy)
@@ -54,6 +54,20 @@ JID=`$PS -p $$ -o jid=`
 #	functions
 #	---------
 
+# list_vars pattern
+#	List vars matching pattern.
+# 
+list_vars()
+{
+	set | { while read LINE; do
+		var="${LINE%%=*}"
+		case "$var" in
+		"$LINE"|*[!a-zA-Z0-9_]*) continue ;;
+		$1) echo $var
+		esac
+	done; }
+}
+
 # set_rcvar_obsolete oldvar [newvar] [msg]
 #	Define obsolete variable.
 #	Global variable $rcvars_obsolete is used.