diff --git a/package/base-files/default/lib/network/config.sh b/package/base-files/default/lib/network/config.sh
index a66c92bc03..25c7278e99 100755
--- a/package/base-files/default/lib/network/config.sh
+++ b/package/base-files/default/lib/network/config.sh
@@ -120,8 +120,9 @@ setup_interface() {
 			env -i ACTION="ifup" INTERFACE="config" DEVICE="$iface" PROTO=static /sbin/hotplug "iface" &
 		;;
 		dhcp)
+			# prevent udhcpc from starting more than once
 			pid="$(cat "$pidfile" 2>/dev/null)"
-			[ -n "$pid" -a -d "/proc/$pid" ] && kill -9 "$pid"
+			[ -d "/proc/$pid" ] && grep udhcpc "/proc/${pid}/cmdline" >/dev/null 2>/dev/null && return 0
 
 			config_get ipaddr "$config" ipaddr
 			config_get netmask "$config" netmask
diff --git a/package/base-files/default/sbin/ifdown b/package/base-files/default/sbin/ifdown
index 073e80d2da..37d0918e85 100755
--- a/package/base-files/default/sbin/ifdown
+++ b/package/base-files/default/sbin/ifdown
@@ -12,23 +12,26 @@ debug "### ifdown $cfg ###"
 config_get proto "$cfg" proto
 [ -z "$proto" ] && { echo "interface not found."; exit; }
 
-# kill active ppp daemon
-pid="$(cat /var/run/ppp-${cfg}.pid 2>/dev/null)"
-[ -n "$pid" -a -d "/proc/$pid" ] && {
-	kill $pid
-	sleep 1
-	[ -d "/proc/$pid" ] && kill -9 $pid
-}
-
-# kill any other process associated with the interface
+# kill active ppp daemon and other processes
 config_get ifname "$cfg" ifname
-pid="$(cat /var/run/${ifname}.pid 2>/dev/null)"
-[ -n "$pid" -a -d "/proc/$pid" ] && kill -9 $pid
+pids="$(cat /var/run/${ifname}.pid /var/run/ppp-${cfg}.pid 2>/dev/null)"
+for pid in $pids; do 
+	[ -d "/proc/$pid" ] && {
+		kill $pid
+		sleep 1
+		[ -d "/proc/$pid" ] && kill -9 $pid
+	}
+done
+rm -f /var/run/${ifname}.pid /var/run/ppp-${cfg}.pid
 
 config_get ifname "$cfg" ifname
-ifconfig "$ifname" >/dev/null 2>/dev/null && {
-	ifconfig "$ifname" 0.0.0.0 down
+config_get device "$cfg" ifname
+
+[ ."$device" != ."$ifname" ] || device=
+for dev in $ifname $device; do
+	ifconfig "$ifname" 0.0.0.0 down >/dev/null 2>/dev/null
+done
+
+config_get iftype "$cfg" type
+[ "$iftype" = "bridge" ] && brctl delbr "$ifname" >/dev/null 2>/dev/null
 
-	config_get iftype "$cfg" type
-	[ "$iftype" = "bridge" ] && brctl delbr "$ifname"
-}
diff --git a/package/base-files/default/sbin/ifup b/package/base-files/default/sbin/ifup
index c7055d4807..81ec2c0890 100755
--- a/package/base-files/default/sbin/ifup
+++ b/package/base-files/default/sbin/ifup
@@ -4,10 +4,7 @@
 . /sbin/ifdown "$@"
 
 config_get iftype "$1" type
-case "$iftype" in
-	bridge) config_get ifname "$1" ifnames;;
-	*) config_get ifname "$1" ifname;;
-esac
+config_get ifname "$1" device
 
 for dev in $ifname; do
 	setup_interface "$dev" "$1"
diff --git a/package/ppp/files/ppp.sh b/package/ppp/files/ppp.sh
index 343223af1b..133400509c 100644
--- a/package/ppp/files/ppp.sh
+++ b/package/ppp/files/ppp.sh
@@ -7,6 +7,11 @@ scan_ppp() {
 
 start_pppd() {
 	local cfg="$1"; shift
+	
+	# make sure only one pppd process is started
+	local pid="$(cat /var/run/ppp-${cfg}.pid 2>/dev/null)"
+	[ -d "/proc/$pid" ] && grep pppd "/proc/$pid/cmdline" 2>/dev/null >/dev/null && return 0
+
 	config_get device "$cfg" device
 	config_get unit "$cfg" unit
 	config_get username "$cfg" username