diff --git a/openwrt/.gitignore b/openwrt/.gitignore
new file mode 100644
index 0000000..55a0f9b
--- /dev/null
+++ b/openwrt/.gitignore
@@ -0,0 +1,2 @@
+*.rootpw
+*.public_key
diff --git a/openwrt/microuter-n300-firmware-upgrade.sh b/openwrt/microuter-n300-firmware-upgrade.sh
new file mode 100755
index 0000000..ed1e21b
--- /dev/null
+++ b/openwrt/microuter-n300-firmware-upgrade.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+# 2022-01-20, Nico Schottelius
+# See https://ungleich.ch/u/products/device-ipv6-box/
+
+if [ $# -ne 1 ]; then
+    echo "$0 address"
+    echo "    address: connect to this address"
+    exit 1
+fi
+
+set -x
+
+device_ip=$1; shift
+
+# openwrt
+version=21.02.0
+filename=openwrt-${version}-ramips-mt76x8-glinet_microuter-n300-squashfs-sysupgrade.bin
+
+# don't care about other/old known_host entries
+ssh-keygen  -R ${device_ip}
+
+while ! ping -c1 ${device_ip}; do
+    echo "Cannot ping $device_ip yet - waiting"
+    sleep 1
+done
+
+cat ~/.ssh/id_rsa.pub | ssh root@${device_ip} "cat > /etc/dropbear/authorized_keys"
+
+# Don't re-download if we already have it
+wget -c http://downloads.openwrt.org/releases/${version}/targets/ramips/mt76x8/${filename}
+
+if echo $device_ip | grep -q :; then
+    scp_ip="[$device_ip]"
+else
+    scp_ip="$device_ip"
+fi
+
+scp ${filename} root@${scp_ip}:/tmp
+ssh root@${device_ip} "sysupgrade -n /tmp/*.bin"