zephyr - prj_dtls.conf (working DTLS config for BLE Nano 2) - IPv6 only

prj_dtls.conf

CONFIG_NETWORKING=y
CONFIG_NET_LOG=y
CONFIG_NET_BUF_LOG=y
CONFIG_SYS_LOG_NET_LEVEL=4
CONFIG_SYS_LOG_NET_BUF_LEVEL=2
CONFIG_SYS_LOG_LWM2M_LEVEL=4
CONFIG_TEST_RANDOM_GENERATOR=y
CONFIG_NET_IPV6=y
CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=3
CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=2
CONFIG_NET_IPV4=n
CONFIG_NET_DHCPV4=n
CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=3
CONFIG_NET_IF_MCAST_IPV4_ADDR_COUNT=2
CONFIG_SYS_LOG_SHOW_COLOR=y
CONFIG_INIT_STACKS=y
CONFIG_PRINTK=y
CONFIG_NET_STATISTICS=y
CONFIG_NET_PKT_RX_COUNT=10
CONFIG_NET_PKT_TX_COUNT=10
CONFIG_NET_BUF_RX_COUNT=10
CONFIG_NET_BUF_TX_COUNT=10
CONFIG_NET_MAX_CONTEXTS=5
# CONFIG_NET_CONTEXT_NET_PKT_POOL is not set

CONFIG_NET_SHELL=y

CONFIG_NET_APP_NEED_IPV6=y
CONFIG_NET_APP_NEED_IPV4=n
CONFIG_NET_APP_SETTINGS=y
CONFIG_NET_APP_DTLS=y

CONFIG_MBEDTLS=y
CONFIG_MBEDTLS_BUILTIN=y
CONFIG_MBEDTLS_ENABLE_HEAP=y
CONFIG_MBEDTLS_HEAP_SIZE=8192
CONFIG_MBEDTLS_CFG_FILE="config-coap.h"

CONFIG_LWM2M=y
CONFIG_LWM2M_PEER_PORT=5684
CONFIG_LWM2M_IPSO_SUPPORT=y
CONFIG_LWM2M_IPSO_TEMP_SENSOR=y
CONFIG_LWM2M_IPSO_LIGHT_CONTROL=y

CONFIG_NET_APP_MY_IPV6_ADDR="2001:db8::1"
CONFIG_NET_APP_PEER_IPV6_ADDR="2001:db8::2"
CONFIG_NET_APP_MY_IPV4_ADDR="192.0.2.1"
CONFIG_NET_APP_PEER_IPV4_ADDR="192.0.2.2"

CONFIG_NET_L2_BT=y
CONFIG_BT_DEVICE_NAME="Test IPSP node"
CONFIG_NET_APP_BT_NODE=y

for more information regarding the setup, check the Zephyr mailing list thread for more information.