diff --git a/netdev.sh b/netdev.sh
index 45eefac..166def3 100755
--- a/netdev.sh
+++ b/netdev.sh
@@ -7,20 +7,25 @@ header_eb() {
 }
 
 header_if() {
-	echo "define INTERFACE $1"
+	local if="${1:?missing if}"
+	echo "define INTERFACE $if"
 }
 
 header_addr() {
-	echo "define ADDR $1"
+	local addr="${1:?missing addr}"
+	echo "define ADDR $addr"
 }
 
 header_vlan() {
-	echo "define VLAN $1"
-	echo "define PARENT $2"
+	local vlan="${1:?missing vlan}"
+	local parent="${2:?missing parent}"
+	echo "define VLAN $vlan"
+	echo "define PARENT $parent"
 }
 
 header_vrf() {
-	echo "define VRF $1"
+	local vrf="${1:?missing vrf}"
+	echo "define VRF $vrf"
 }
 
 header_path() {
@@ -44,12 +49,13 @@ h_if_addr() {
 }
 
 linkdel() {
-	h_if "$1"
+	local if="${1:?missing if}"
+	h_if "$if"
 	echo 'ip link del $INTERFACE'
 }
 
 ifbundle() {
-	local if="$1"
+	local if="${1:?missing if}"
 	[ -r "rc/bundle.interface.$if/type" ] || install -Dm644 <(echo bundle) rc/bundle.interface."$if"/type
 	shift 1
 	for sname in $@; do
@@ -58,7 +64,7 @@ ifbundle() {
 }
 
 new_link() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="interface.$if.link"
 
@@ -75,7 +81,7 @@ new_link() {
 }
 
 new_forward() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="sysctl.net-ipv6-conf-$if-forwarding"
 	ifbundle "$if" "$sname"
@@ -106,8 +112,8 @@ EOF
 }
 
 new_if_slave() {
-	local master="$1"
-	local slave="$2"
+	local master="${1:?missing master}"
+	local slave="${2:?missing slave}"
 
 	local sname="interface.$master.slave.$slave"
 	ifbundle "$master" "$sname"
@@ -135,7 +141,7 @@ EOF
 }
 
 new_if_bridge() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="interface.$if.create"
 	ifbundle "$if" "$sname"
@@ -151,8 +157,46 @@ new_if_bridge() {
 	new_link "$if"
 }
 
+bridge_stp() {
+	local if="${1:?missing if}"
+	local state="${2:-1}"
+
+	local sname="interface.$if.stp"
+	ifbundle "$if" "$sname"
+
+	install -Dm644 <(
+		h_if "$if"
+		cat <<EOF
+define STATE $state
+EOF
+		echo 'ip link set $INTERFACE type bridge stp_state $STATE'
+	) rc/"$sname"/up
+	install -Dm644 <(
+		h_if "$if"
+		echo 'ip link set $INTERFACE type bridge stp_state 0'
+	) rc/"$sname"/down
+	install -Dm644 <(echo oneshot) rc/"$sname"/type
+	install -Dm644 /dev/null rc/"$sname"/dependencies.d/module.stp
+	install -Dm644 /dev/null rc/"$sname"/dependencies.d/interface."$if".create
+}
+
+if_lladdress() {
+	local if="${1:?missing if}"
+	local addr="${2:?missing addr}"
+
+	local sname="interface.$if.lladdr"
+	ifbundle "$if" "$sname"
+
+	install -Dm644 <(
+		h_if_addr "$if" "$addr"
+		echo 'ip link set $INTERFACE address $ADDR'
+	) rc/"$sname"/up
+	install -Dm644 <(echo oneshot) rc/"$sname"/type
+	install -Dm644 /dev/null rc/"$sname"/dependencies.d/interface."$if".create
+}
+
 new_if_phys() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="interface.$if.create"
 	ifbundle "$if" "$sname"
@@ -168,7 +212,7 @@ new_if_phys() {
 }
 
 new_if_wg() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	# Main service for creating interface
 	local sname="interface.$if.create"
@@ -189,7 +233,7 @@ new_if_wg() {
 }
 
 wgconf() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="interface.$if.wg-config"
 	ifbundle "$if" "$sname"
@@ -210,8 +254,8 @@ EOF
 }
 
 new_if_vrf() {
-	local if="$1"
-	local table="$2"
+	local if="${1:?missing if}"
+	local table="${2:?missing table}"
 
 	local sname="interface.$if.create"
 	ifbundle "$if" "$sname"
@@ -236,7 +280,7 @@ EOF
 }
 
 new_if_vlan() {
-	local if="$1"
+	local if="${1:?missing if}"
 	local vlan="$(echo $if | cut -d'-' -f2)"
 	local parent="$(echo $if | cut -d'-' -f1)"
 
@@ -259,8 +303,8 @@ new_if_vlan() {
 }
 
 addr_v6_static_if() {
-	local if="$1"
-	local addr="$2"
+	local if="${1:?missing if}"
+	local addr="${2:?missing addr}"
 	local addrn="$(echo "$addr" | sed 's/\//_/g')"
 
 	local sname="interface.$if.static.addr.6.$addrn"
@@ -279,8 +323,8 @@ addr_v6_static_if() {
 }
 
 route_v6_vrf_default_if() {
-	local vrf="$1"
-	local if="$2"
+	local vrf="${1:?missing vrf}"
+	local if="${2:?missing if}"
 
 	local sname="interface.$vrf.route.6.default"
 	ifbundle "$vrf" "$sname"
@@ -301,7 +345,7 @@ route_v6_vrf_default_if() {
 }
 
 route_v6_vrf_default_unreach() {
-	local if="$1"
+	local if="${1:?missing if}"
 
 	local sname="interface.$if.route.6.unreach"
 	ifbundle "$if" "$sname"
@@ -319,8 +363,8 @@ route_v6_vrf_default_unreach() {
 }
 
 route_v6_vrf_sink_unreach() {
-	local if="$1"
-	local addr="$2"
+	local if="${1:?missing if}"
+	local addr="${2:?missing addr}"
 	local addrn="$(echo "$addr" | sed 's/\//_/g')"
 
 	local sname="interface.$if.route.6.sink.$addrn"
diff --git a/router.sh b/router.sh
index b4dffcf..00c27d7 100755
--- a/router.sh
+++ b/router.sh
@@ -29,16 +29,22 @@ new_if_bridge "br-dn42"
 	new_if_slave "br-dn42" "phys2-42"
 
 new_if_bridge "f33d"
+	bridge_stp "f33d"
+	if_lladdress "f33d" '02:00:00:00:f3:3d'
 	addr_v6_static_if "f33d" "2a04:5b81:2060:f33d::1/64"
 	new_if_slave "f33d" "vnet2"
 
 new_if_bridge "b00b"
+	bridge_stp "b00b"
+	if_lladdress "b00b" '02:00:00:00:b0:0b'
 	addr_v6_static_if "b00b" "2a04:5b81:2060:b00b::1/64"
 	new_if_slave "b00b" "vnet0"
 	new_if_slave "b00b" "vnet4"
 	new_if_slave "b00b" "phys2-66"
 
 new_if_bridge "d00d"
+	bridge_stp "d00d"
+	if_lladdress "d00d" '02:00:00:00:d0:0d'
 	addr_v6_static_if "d00d" "2a04:5b81:2060:d00d::1/64"
 	new_if_slave "d00d" "vnet3"