marcolarosa/gist:e95df344552ea10a31775ea7f81e2c12

## gistfile1.txt
#!/bin/bash


is_private_network() {
    NETWORK=${1}

    is_private=0
    for i in $(seq 0 255); do
        match=$(echo $NETWORK | grep "10.$i")
        [[ ! -z $match ]] && is_private=1
    done
    for i in $(seq 16 31); do
        match=$(echo $NETWORK | grep "172.$i")
        [[ ! -z $match ]] && is_private=1
    done
    match=$(echo $NETWORK | grep "192.168")
    [[ ! -z $match ]] && is_private=1
    echo $is_private

}

INTERFACES=$(ip a s | grep -E "inet.*eth" | awk '{print $8}')

# is there only one interface - do nothing
if [ $(echo $INTERFACES | wc -w) == 1 ] ; then
    echo "Only one interface attached to this host so nothing to do"
    exit 0
fi

# check each interface and remove default routes to private networks
for int in $INTERFACES; do
    INTERFACE_IP=$(ip a s | grep -E "inet.*${int}" | awk '{print $2}' | awk -F '.' '{print $1"."$2}')
    IS_PRIVATE_NETWORK=$(is_private_network $INTERFACE_IP)

    if [ $IS_PRIVATE_NETWORK == 1 ] ; then
        # looks like a private network so remove default route if any
        ROUTE=$(route | grep $INTERFACE_IP | grep default)
        if [ ! -z "$ROUTE" ] ; then
            NET=$(echo $ROUTE | awk '{print $3}')
            GW=$(echo $ROUTE | awk '{print $2}')
            route del -net $NET gw $GW
        fi
    fi
done
	#!/bin/bash


	is_private_network() {
	NETWORK=${1}

	is_private=0
	for i in $(seq 0 255); do
	match=$(echo $NETWORK \| grep "10.$i")
	[[ ! -z $match ]] && is_private=1
	done
	for i in $(seq 16 31); do
	match=$(echo $NETWORK \| grep "172.$i")
	[[ ! -z $match ]] && is_private=1
	done
	match=$(echo $NETWORK \| grep "192.168")
	[[ ! -z $match ]] && is_private=1
	echo $is_private

	}

	INTERFACES=$(ip a s \| grep -E "inet.*eth" \| awk '{print $8}')

	# is there only one interface - do nothing
	if [ $(echo $INTERFACES \| wc -w) == 1 ] ; then
	echo "Only one interface attached to this host so nothing to do"
	exit 0
	fi

	# check each interface and remove default routes to private networks
	for int in $INTERFACES; do
	INTERFACE_IP=$(ip a s \| grep -E "inet.*${int}" \| awk '{print $2}' \| awk -F '.' '{print $1"."$2}')
	IS_PRIVATE_NETWORK=$(is_private_network $INTERFACE_IP)

	if [ $IS_PRIVATE_NETWORK == 1 ] ; then
	# looks like a private network so remove default route if any
	ROUTE=$(route \| grep $INTERFACE_IP \| grep default)
	if [ ! -z "$ROUTE" ] ; then
	NET=$(echo $ROUTE \| awk '{print $3}')
	GW=$(echo $ROUTE \| awk '{print $2}')
	route del -net $NET gw $GW
	fi
	fi
	done