diff --git a/openwrt/vigir-1-firmware-upgrade.sh b/openwrt/vigir-1-firmware-upgrade.sh
index e192bc9..9f988f4 100755
--- a/openwrt/vigir-1-firmware-upgrade.sh
+++ b/openwrt/vigir-1-firmware-upgrade.sh
@@ -2,38 +2,19 @@
 # 2020-06-13, Nico Schottelius
 # See https://ungleich.ch/u/products/viirb-ipv6-box/
 
-if [ $# -lt 1 ]; then
+if [ $# -ne 1 ]; then
     echo "$0 interface [address]"
-    echo "    interface to add the config ip address to"
     echo "    address: connect to this address, ignore the interface"
     exit 1
 fi
 
 set -x
-dev=$1; shift
-
-# $# = 2
-# shift -> remove the first argument
-# $# = 1
-
-if [ $# -ge 1 ]; then
-    vigir_ip=$1; shift
-    dev=""
-else
-    vigir_ip=192.168.8.1
-fi
+vigir_ip=$1; shift
 
 # openwrt
 version=19.07.5
 filename=openwrt-${version}-ramips-mt7621-zbt-wg3526-16M-squashfs-sysupgrade.bin
 
-# IP address for setting it up initially
-
-if [ "$dev" ]; then
-    sudo ip addr del 192.168.8.2/24 dev "$dev" 2>/dev/null || true
-    sudo ip addr add 192.168.8.2/24 dev "$dev"
-fi
-
 # don't care about other/old known_host entries
 ssh-keygen  -R ${vigir_ip}
 
diff --git a/openwrt/viirb-1-firmware-upgrade.sh b/openwrt/viirb-1-firmware-upgrade.sh
index 0c52ab3..4cdace7 100755
--- a/openwrt/viirb-1-firmware-upgrade.sh
+++ b/openwrt/viirb-1-firmware-upgrade.sh
@@ -2,38 +2,20 @@
 # 2020-06-13, Nico Schottelius
 # See https://ungleich.ch/u/products/viirb-ipv6-box/
 
-if [ $# -lt 1 ]; then
+if [ $# -ne 1 ]; then
     echo "$0 interface [address]"
-    echo "    interface to add the config ip address to"
     echo "    address: connect to this address, ignore the interface"
     exit 1
 fi
 
 set -x
-dev=$1; shift
 
-# $# = 2
-# shift -> remove the first argument
-# $# = 1
-
-if [ $# -ge 1 ]; then
-    viirb_ip=$1; shift
-    dev=""
-else
-    viirb_ip=192.168.61.1
-fi
+viirb_ip=$1; shift
 
 # openwrt
 version=19.07.5
 filename=openwrt-${version}-ramips-mt76x8-vocore2-squashfs-sysupgrade.bin
 
-# IP address for setting it up initially
-
-if [ "$dev" ]; then
-    sudo ip addr del 192.168.61.2/24 dev "$dev" 2>/dev/null || true
-    sudo ip addr add 192.168.61.2/24 dev "$dev"
-fi
-
 # don't care about other/old known_host entries
 ssh-keygen  -R ${viirb_ip}