diff --git a/functions b/functions
index 3a3e28bcdb..ba3ce652ed 100644
--- a/functions
+++ b/functions
@@ -18,15 +18,38 @@ XTRACE=$(set +o | grep xtrace)
 set +o xtrace
 
 
-# Exit 0 if address is in network or 1 if address is not in
-# network or netaddr library is not installed.
+# Convert CIDR notation to a IPv4 netmask
+# cidr2netmask cidr-bits
+function cidr2netmask() {
+    local maskpat="255 255 255 255"
+    local maskdgt="254 252 248 240 224 192 128"
+    set -- ${maskpat:0:$(( ($1 / 8) * 4 ))}${maskdgt:$(( (7 - ($1 % 8)) * 4 )):3}
+    echo ${1-0}.${2-0}.${3-0}.${4-0}
+}
+
+
+# Return the network portion of the given IP address using netmask
+# netmask is in the traditional dotted-quad format
+# maskip ip-address netmask
+function maskip() {
+    local ip=$1
+    local mask=$2
+    local l="${ip%.*}"; local r="${ip#*.}"; local n="${mask%.*}"; local m="${mask#*.}"
+    local subnet=$((${ip%%.*}&${mask%%.*})).$((${r%%.*}&${m%%.*})).$((${l##*.}&${n##*.})).$((${ip##*.}&${mask##*.}))
+    echo $subnet
+}
+
+
+# Exit 0 if address is in network or 1 if address is not in network
+# ip-range is in CIDR notation: 1.2.3.4/20
 # address_in_net ip-address ip-range
 function address_in_net() {
-    python -c "
-import netaddr
-import sys
-sys.exit(netaddr.IPAddress('$1') not in netaddr.IPNetwork('$2'))
-"
+    local ip=$1
+    local range=$2
+    local masklen=${range#*/}
+    local network=$(maskip ${range%/*} $(cidr2netmask $masklen))
+    local subnet=$(maskip $ip $(cidr2netmask $masklen))
+    [[ $network == $subnet ]]
 }
 
 
diff --git a/tests/test_ip.sh b/tests/test_ip.sh
new file mode 100755
index 0000000000..e9cbcca4a4
--- /dev/null
+++ b/tests/test_ip.sh
@@ -0,0 +1,118 @@
+#!/usr/bin/env bash
+
+# Tests for DevStack functions
+# address_in_net()
+
+TOP=$(cd $(dirname "$0")/.. && pwd)
+
+# Import common functions
+source $TOP/functions
+
+# Import configuration
+source $TOP/openrc
+
+
+echo "Testing IP addr functions"
+
+if [[ $(cidr2netmask 4) == 240.0.0.0 ]]; then
+    echo "cidr2netmask(): /4...OK"
+else
+    echo "cidr2netmask(): /4...failed"
+fi
+if [[ $(cidr2netmask 8) == 255.0.0.0 ]]; then
+    echo "cidr2netmask(): /8...OK"
+else
+    echo "cidr2netmask(): /8...failed"
+fi
+if [[ $(cidr2netmask 12) == 255.240.0.0 ]]; then
+    echo "cidr2netmask(): /12...OK"
+else
+    echo "cidr2netmask(): /12...failed"
+fi
+if [[ $(cidr2netmask 16) == 255.255.0.0 ]]; then
+    echo "cidr2netmask(): /16...OK"
+else
+    echo "cidr2netmask(): /16...failed"
+fi
+if [[ $(cidr2netmask 20) == 255.255.240.0 ]]; then
+    echo "cidr2netmask(): /20...OK"
+else
+    echo "cidr2netmask(): /20...failed"
+fi
+if [[ $(cidr2netmask 24) == 255.255.255.0 ]]; then
+    echo "cidr2netmask(): /24...OK"
+else
+    echo "cidr2netmask(): /24...failed"
+fi
+if [[ $(cidr2netmask 28) == 255.255.255.240 ]]; then
+    echo "cidr2netmask(): /28...OK"
+else
+    echo "cidr2netmask(): /28...failed"
+fi
+if [[ $(cidr2netmask 30) == 255.255.255.252 ]]; then
+    echo "cidr2netmask(): /30...OK"
+else
+    echo "cidr2netmask(): /30...failed"
+fi
+if [[ $(cidr2netmask 32) == 255.255.255.255 ]]; then
+    echo "cidr2netmask(): /32...OK"
+else
+    echo "cidr2netmask(): /32...failed"
+fi
+
+if [[ $(maskip 169.254.169.254 240.0.0.0) == 160.0.0.0 ]]; then
+    echo "maskip(): /4...OK"
+else
+    echo "maskip(): /4...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.0.0.0) == 169.0.0.0 ]]; then
+    echo "maskip(): /8...OK"
+else
+    echo "maskip(): /8...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.240.0.0) == 169.240.0.0 ]]; then
+    echo "maskip(): /12...OK"
+else
+    echo "maskip(): /12...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.255.0.0) == 169.254.0.0 ]]; then
+    echo "maskip(): /16...OK"
+else
+    echo "maskip(): /16...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.255.240.0) == 169.254.160.0 ]]; then
+    echo "maskip(): /20...OK"
+else
+    echo "maskip(): /20...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.255.255.0) == 169.254.169.0 ]]; then
+    echo "maskip(): /24...OK"
+else
+    echo "maskip(): /24...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.255.255.240) == 169.254.169.240 ]]; then
+    echo "maskip(): /28...OK"
+else
+    echo "maskip(): /28...failed"
+fi
+if [[ $(maskip 169.254.169.254 255.255.255.255) == 169.254.169.254 ]]; then
+    echo "maskip(): /32...OK"
+else
+    echo "maskip(): /32...failed"
+fi
+
+for mask in 8 12 16 20 24 26 28; do
+    echo -n "address_in_net(): in /$mask..."
+    if address_in_net 10.10.10.1 10.10.10.0/$mask; then
+        echo "OK"
+    else
+        echo "address_in_net() failed on /$mask"
+    fi
+
+    echo -n "address_in_net(): not in /$mask..."
+    if ! address_in_net 10.10.10.1 11.11.11.0/$mask; then
+        echo "OK"
+    else
+        echo "address_in_net() failed on /$mask"
+    fi
+done