diff --git a/Makefile.dep b/Makefile.dep
index 31fbbaea22de34b32bdb59ed2576c3355e9bbb6b..46c5a37492edde8ae3ea585d9c31f692a1d23bb3 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -310,6 +310,11 @@ ifneq (,$(filter gnrc_ipv6_nc,$(USEMODULE)))
USEMODULE += ipv6_addr
endif
+ifneq (,$(filter gnrc_ipv6_nib,$(USEMODULE)))
+ USEMODULE += ipv6_addr
+ USEMODULE += random
+endif
+
ifneq (,$(filter gnrc_ipv6_netif,$(USEMODULE)))
USEMODULE += ipv6_addr
USEMODULE += gnrc_netif
diff --git a/sys/include/net/gnrc/ipv6/nib.h b/sys/include/net/gnrc/ipv6/nib.h
new file mode 100644
index 0000000000000000000000000000000000000000..f132517a4ffbff7e0cf2c750aad823a949f01337
--- /dev/null
+++ b/sys/include/net/gnrc/ipv6/nib.h
@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup net_gnrc_ipv6_nib Neighbor Information Base for IPv6
+ * @ingroup net_gnrc_ipv6
+ * @brief Neighbor Information Base (NIB) for IPv6
+ *
+ * @todo Add detailed description
+ * @{
+ *
+ * @file
+ * @brief NIB definitions
+ *
+ * @author Martine Lenders <m.lenders@fu-berlin.de>
+ */
+#ifndef NET_GNRC_IPV6_NIB_H
+#define NET_GNRC_IPV6_NIB_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name Timer event message types
+ * @anchor net_gnrc_ipv6_nib_msg
+ * @{
+ */
+/**
+ * @brief (Re-)transmit unicast Neighbor Solicitation event.
+ *
+ * This message type is for the event of (re-)transmitting of unicast Neighbor
+ * Solicitation. The expected message context is a pointer to a valid on-link
+ * entry representing the neighbor to which the Neighbor Solicitation is
+ * supposed to be sent.
+ */
+#define GNRC_IPV6_NIB_SND_UC_NS (0x4fc0U)
+
+/**
+ * @brief (Re-)transmit multicast Neighbor Solicitation event.
+ *
+ * This message type is for the event of (re-)transmitting of multicast Neighbor
+ * Solicitation. The expected message context is a pointer to a valid on-link
+ * entry representing the neighbor to which [solicited
+ * nodes](https://tools.ietf.org/html/rfc4291#section-2.7.1) group
+ * the Neighbor Solicitation is supposed to be sent.
+ */
+#define GNRC_IPV6_NIB_SND_MC_NS (0x4fc1U)
+
+/**
+ * @brief Send delayed Neighbor Advertisement event.
+ *
+ * This message type is for the event of sending delayed Neighbor
+ * Advertisements. The expected message context is a pointer to a valid
+ * [packet snip](@ref gnrc_pktsnip_t) in *sending order*, representing the
+ * Neighbor Advertisement.
+ */
+#define GNRC_IPV6_NIB_SND_NA (0x4fc2U)
+
+/**
+ * @brief Search router event.
+ *
+ * This message type is for the event of searching a (new) router (which
+ * implies sending a multicast Router Solicitation). The expected message
+ * context is a pointer to a valid interface behind which the router is
+ * searched.
+ */
+#define GNRC_IPV6_NIB_SEARCH_RTR (0x4fc3U)
+
+/**
+ * @brief Reconfirm router event.
+ *
+ * This message type is for the event the reconfirmation of a router (which
+ * implies sending a unicast Router Solicitation). The expected message context
+ * is a pointer to a valid on-link entry representing the router that is to be
+ * confirmed.
+ */
+#define GNRC_IPV6_NIB_RECONFIRM_RTR (0x4fc4U)
+
+/**
+ * @brief Reply Router Solicitation event.
+ *
+ * This message type is for the event of the delayed reply to a Router
+ * Solicitaion with a Router Advertisement. The expected message context is a
+ * pointer to a valid on-link entry representing the neighbor that sent the
+ * Router Solicitation.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_ROUTER != 0
+ */
+#define GNRC_IPV6_NIB_REPLY_RS (0x4fc5U)
+
+/**
+ * @brief (Re-)transmit multicast Router Advertisement event.
+ *
+ * This message type is for the event of (Re)transmit Advertisements
+ * event. The expected message context is a pointer to a valid interface over
+ * which the Router Advertisement will be sent and by which parameters it will
+ * be configured.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_ROUTER != 0
+ */
+#define GNRC_IPV6_NIB_SND_MC_RA (0x4fc6U)
+
+/**
+ * @brief Reachability timeout event.
+ *
+ * This message type is for the event of a REACHABLE state timeout.
+ * The expected message context is a pointer to a valid on-link entry
+ * representing the neighbor cache entry that faces a state change.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_ARSM != 0
+ */
+#define GNRC_IPV6_NIB_REACH_TIMEOUT (0x4fc7U)
+
+/**
+ * @brief Delay timeout event.
+ *
+ * This message type is for the event of the DELAY state timeout.
+ * The expected message context is a pointer to a valid on-link entry
+ * representing the neighbor cache entry that faces a state change.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_ARSM != 0
+ */
+#define GNRC_IPV6_NIB_DELAY_TIMEOUT (0x4fc8U)
+
+/**
+ * @brief Address registration timeout event.
+ *
+ * This message type is for the event of a 6LoWPAN address registration state
+ * timeout. The expected message context is a pointer to a valid on-link entry
+ * representing the neighbor which faces a timeout of its address registration.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_6LR != 0
+ */
+#define GNRC_IPV6_NIB_ADDR_REG_TIMEOUT (0x4fc9U)
+
+/**
+ * @brief 6LoWPAN context timeout event.
+ *
+ * This message type is for the event of a 6LoWPAN compression context timeout.
+ * The expected message context is the compression context's numerical
+ * identifier.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_6LN != 0
+ */
+#define GNRC_IPV6_NIB_6LO_CTX_TIMEOUT (0x4fcaU)
+
+/**
+ * @brief Authoritative border router timeout event.
+ *
+ * This message type is for the event of an Authoritative border router timeout.
+ * The expected message context is the NIB-internal state of the authoritative
+ * border router.
+ *
+ * @note Only handled with @ref GNRC_IPV6_NIB_CONF_MULTIHOP_P6C != 0
+ */
+#define GNRC_IPV6_NIB_ABR_TIMEOUT (0x4fcbU)
+
+/**
+ * @brief Prefix timeout event.
+ *
+ * This message type is for the event of a prefix timeout. The expected message
+ * context is a valid off-link entry representing the prefix.
+ */
+#define GNRC_IPV6_NIB_PFX_TIMEOUT (0x4fccU)
+
+/**
+ * @brief Router timeout event.
+ *
+ * This message type is for the event of a router timeout. The expected message
+ * context is a valid default router entry representing the router.
+ */
+#define GNRC_IPV6_NIB_RTR_TIMEOUT (0x4fcdU)
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NET_GNRC_IPV6_NIB_H */
+/** @} */
diff --git a/sys/include/net/gnrc/ipv6/nib/conf.h b/sys/include/net/gnrc/ipv6/nib/conf.h
new file mode 100644
index 0000000000000000000000000000000000000000..0368a695c80f1dedbfd80bc77620669ad2e95f1c
--- /dev/null
+++ b/sys/include/net/gnrc/ipv6/nib/conf.h
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup net_gnrc_ipv6_nib_conf Configuration macros
+ * @ingroup net_gnrc_ipv6_nib
+ * @brief Configuration macros for network information base
+ * @{
+ *
+ * @file
+ * @brief Configuration macro definitions for network information base
+ *
+ * @author Martine Lenders <mlenders@inf.fu-berlin.de>
+ */
+#ifndef NET_GNRC_IPV6_NIB_CONF_H
+#define NET_GNRC_IPV6_NIB_CONF_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name Compile flags
+ * @brief Compile flags to (de-)activate certain features for NIB
+ * @{
+ */
+/**
+ * @brief enable features for 6Lo border router
+ */
+#ifndef GNRC_IPV6_NIB_CONF_6LBR
+#define GNRC_IPV6_NIB_CONF_6LBR (0)
+#endif
+
+/**
+ * @brief enable features for 6Lo router
+ */
+#ifndef GNRC_IPV6_NIB_CONF_6LR
+#if GNRC_IPV6_NIB_CONF_6LBR
+#define GNRC_IPV6_NIB_CONF_6LR (1)
+#else
+#define GNRC_IPV6_NIB_CONF_6LR (0)
+#endif
+#endif
+
+/**
+ * @brief enable features for 6Lo node
+ */
+#ifndef GNRC_IPV6_NIB_CONF_6LN
+#if GNRC_IPV6_NIB_CONF_6LR
+#define GNRC_IPV6_NIB_CONF_6LN (1)
+#else
+#define GNRC_IPV6_NIB_CONF_6LN (0)
+#endif
+#endif
+
+/**
+ * @brief enable features for IPv6 routers
+ */
+#ifndef GNRC_IPV6_NIB_CONF_ROUTER
+#if GNRC_IPV6_NIB_CONF_6LR
+#define GNRC_IPV6_NIB_CONF_ROUTER (1)
+#else
+#define GNRC_IPV6_NIB_CONF_ROUTER (0)
+#endif
+#endif
+
+/**
+ * @brief (de-)activate router advertising at interface start-up
+ */
+#ifndef GNRC_IPV6_NIB_CONF_ADV_ROUTER
+#if GNRC_IPV6_NIB_CONF_ROUTER && \
+ (!GNRC_IPV6_NIB_CONF_6LR || GNRC_IPV6_NIB_CONF_6LBR)
+#define GNRC_IPV6_NIB_CONF_ADV_ROUTER (1)
+#else
+#define GNRC_IPV6_NIB_CONF_ADV_ROUTER (0)
+#endif
+#endif
+
+/**
+ * @brief (de-)activate NDP address resolution state-machine
+ */
+#ifndef GNRC_IPV6_NIB_CONF_ARSM
+#define GNRC_IPV6_NIB_CONF_ARSM (1)
+#endif
+
+/**
+ * @brief queue packets for address resolution
+ */
+#ifndef GNRC_IPV6_NIB_CONF_QUEUE_PKT
+#if GNRC_IPV6_NIB_CONF_6LN
+#define GNRC_IPV6_NIB_CONF_QUEUE_PKT (0)
+#else
+#define GNRC_IPV6_NIB_CONF_QUEUE_PKT (1)
+#endif
+#endif
+
+/**
+ * @brief handle NDP messages according for stateless address
+ * auto-configuration (if activated on interface)
+ *
+ * @see [RFC 4862](https://tools.ietf.org/html/rfc4862)
+ */
+#ifndef GNRC_IPV6_NIB_CONF_SLAAC
+#define GNRC_IPV6_NIB_CONF_SLAAC (1)
+#endif
+
+/**
+ * @brief handle Redirect Messages
+ */
+#ifndef GNRC_IPV6_NIB_CONF_REDIRECT
+#define GNRC_IPV6_NIB_CONF_REDIRECT (0)
+#endif
+
+/**
+ * @brief (de-)activate destination cache
+ */
+#ifndef GNRC_IPV6_NIB_CONF_DC
+#if GNRC_IPV6_NIB_CONF_REDIRECT
+#define GNRC_IPV6_NIB_CONF_DC (1)
+#else
+#define GNRC_IPV6_NIB_CONF_DC (0)
+#endif
+#endif
+
+/**
+ * @brief Multihop prefix and 6LoWPAN context distribution
+ *
+ * @see [RFC 6775, section 8.1](https://tools.ietf.org/html/rfc6775#section-8.1)
+ */
+#ifndef GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
+#define GNRC_IPV6_NIB_CONF_MULTIHOP_P6C (0)
+#endif
+
+/**
+ * @brief Multihop duplicate address detection
+ *
+ * @see [RFC 6775, section 8.2](https://tools.ietf.org/html/rfc6775#section-8.2)
+ */
+#ifndef GNRC_IPV6_NIB_CONF_MULTIHOP_DAD
+#define GNRC_IPV6_NIB_CONF_MULTIHOP_DAD (0)
+#endif
+/** @} */
+
+/**
+ * @brief Reset time in milliseconds for the reachability time
+ *
+ * @see [RFC 4861, section 6.3.4](https://tools.ietf.org/html/rfc4861#section-6.3.4)
+ */
+#ifndef GNRC_IPV6_NIB_CONF_REACH_TIME_RESET
+#define GNRC_IPV6_NIB_CONF_REACH_TIME_RESET (7200000U)
+#endif
+
+/**
+ * @brief Maximum link-layer address length (aligned)
+ */
+#if (GNRC_NETIF_HDR_L2ADDR_MAX_LEN % 8)
+#define GNRC_IPV6_NIB_L2ADDR_MAX_LEN (((GNRC_NETIF_HDR_L2ADDR_MAX_LEN >> 3) + 1) << 3)
+#else
+#define GNRC_IPV6_NIB_L2ADDR_MAX_LEN (GNRC_NETIF_HDR_L2ADDR_MAX_LEN)
+#endif
+
+/**
+ * @brief Number of default routers in the default router list.
+ *
+ * @note **This number has direct influence on the maximum number of
+ * default routers**
+ */
+#ifndef GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF
+#define GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF (1)
+#endif
+
+/**
+ * @brief Number of entries in NIB
+ *
+ * @note **This number has direct influence on the maximum number of
+ * neighbors and duplicate address detection table entries**
+ */
+#ifndef GNRC_IPV6_NIB_NUMOF
+#define GNRC_IPV6_NIB_NUMOF (4)
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NET_GNRC_IPV6_NIB_CONF_H */
+/** @} */
diff --git a/sys/include/net/gnrc/ipv6/nib/nc.h b/sys/include/net/gnrc/ipv6/nib/nc.h
new file mode 100644
index 0000000000000000000000000000000000000000..fd6144fd792bf2dd94853cb14b4edf9e34325004
--- /dev/null
+++ b/sys/include/net/gnrc/ipv6/nib/nc.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup net_gnrc_ipv6_nib_nc Neighbor Cache
+ * @ingroup net_gnrc_ipv6_nib
+ * @brief Neighbor cache component of network information base
+ * @{
+ *
+ * @file
+ * @brief Neighbor cache definitions
+ *
+ * @author Martine Lenders <m.lenders@fu-berlin.de>
+ */
+#ifndef NET_GNRC_IPV6_NIB_NC_H
+#define NET_GNRC_IPV6_NIB_NC_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "net/eui64.h"
+#include "net/gnrc/netif/hdr.h"
+#include "net/gnrc/ipv6/nib/conf.h"
+#include "net/ipv6/addr.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Values for gnrc_ipv6_nib_nc_t::info
+ * @anchor net_gnrc_ipv6_nib_nc_info
+ * @name Info values
+ * @{
+ */
+/**
+ * @brief Mask for neighbor unreachability detection (NUD) states
+ *
+ * @see [RFC 4861, section 7.3.2](https://tools.ietf.org/html/rfc4861#section-7.3.2)
+ * @see [RFC 7048](https://tools.ietf.org/html/rfc7048)
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK (0x0007)
+
+/**
+ * @brief not managed by NUD
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_UNMANAGED (0x0000)
+
+/**
+ * @brief entry is not reachable
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_UNREACHABLE (0x0001)
+
+/**
+ * @brief address resolution is currently performed
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE (0x0002)
+
+/**
+ * @brief address might not be reachable
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_STALE (0x0003)
+
+/**
+ * @brief NUD will be performed in a moment
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_DELAY (0x0004)
+
+/**
+ * @brief NUD is performed
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_PROBE (0x0005)
+
+/**
+ * @brief entry is reachable
+ */
+#define GNRC_IPV6_NIB_NC_INFO_NUD_STATE_REACHABLE (0x0006)
+
+/**
+ * @brief gnrc_ipv6_nib_t::next_hop is router
+ *
+ * This flag indicates that gnrc_ipv6_nib_t::next_hop is a router, but it does
+ * not necessarily indicate that it is in the default router list! A neighbor
+ * that has this flag unset however **must not** appear in the default router
+ * list.
+ *
+ * @see [RFC 4861, Appendix D](https://tools.ietf.org/html/rfc4861#page-91)
+ */
+#define GNRC_IPV6_NIB_NC_INFO_IS_ROUTER (0x0008)
+
+/**
+ * @brief Mask for interface identifier
+ */
+#define GNRC_IPV6_NIB_NC_INFO_IFACE_MASK (0x01f0)
+
+/**
+ * @brief Shift position of interface identifier
+ */
+#define GNRC_IPV6_NIB_NC_INFO_IFACE_POS (4)
+
+/**
+ * @brief Mask for 6LoWPAN address registration (6Lo-AR) states
+ *
+ * @see [RFC 6775, section 3.5](https://tools.ietf.org/html/rfc6775#section-3.5)
+ */
+#define GNRC_IPV6_NIB_NC_INFO_AR_STATE_MASK (0x0600)
+
+/**
+ * @brief not managed by 6Lo-AR (address can be removed when memory is low
+ */
+#define GNRC_IPV6_NIB_NC_INFO_AR_STATE_GC (0x0000)
+
+/**
+ * @brief address registration still pending at upstream router
+ */
+#define GNRC_IPV6_NIB_NC_INFO_AR_STATE_TENTATIVE (0x0200)
+
+/**
+ * @brief address is registered
+ */
+#define GNRC_IPV6_NIB_NC_INFO_AR_STATE_REGISTERED (0x0600)
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NET_GNRC_IPV6_NIB_NC_H */
+/** @} */
diff --git a/sys/net/gnrc/Makefile b/sys/net/gnrc/Makefile
index 05798bbbe1882439dabdaccea7029b6a3ccff328..e03f6f26d661acd1e07dfeec6d223c68ca55c8c9 100644
--- a/sys/net/gnrc/Makefile
+++ b/sys/net/gnrc/Makefile
@@ -22,6 +22,9 @@ endif
ifneq (,$(filter gnrc_ipv6_netif,$(USEMODULE)))
DIRS += network_layer/ipv6/netif
endif
+ifneq (,$(filter gnrc_ipv6_nib,$(USEMODULE)))
+ DIRS += network_layer/ipv6/nib
+endif
ifneq (,$(filter gnrc_ipv6_whitelist,$(USEMODULE)))
DIRS += network_layer/ipv6/whitelist
endif
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/Makefile b/sys/net/gnrc/network_layer/ipv6/nib/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..600c639297f5286d05021b118e17cf00e219d151
--- /dev/null
+++ b/sys/net/gnrc/network_layer/ipv6/nib/Makefile
@@ -0,0 +1,3 @@
+MODULE = gnrc_ipv6_nib
+
+include $(RIOTBASE)/Makefile.base
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c
new file mode 100644
index 0000000000000000000000000000000000000000..0a316bb5adef61588bfd2fcda4b2c34238ee9c8e
--- /dev/null
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.c
@@ -0,0 +1,387 @@
+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @{
+ *
+ * @file
+ * @author Martine Lenders <m.lenders@fu-berlin.de>
+ */
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "net/gnrc/ipv6.h"
+#include "net/gnrc/ipv6/nib/conf.h"
+#include "net/gnrc/ipv6/nib/nc.h"
+#include "net/gnrc/ipv6/nib.h"
+#include "net/gnrc/netif.h"
+#include "random.h"
+
+#include "_nib-internal.h"
+
+#define ENABLE_DEBUG (0)
+#include "debug.h"
+
+/* pointers for default router selection */
+static _nib_dr_entry_t *_prime_def_router = NULL;
+static clist_node_t _next_removable = { NULL };
+
+static _nib_onl_entry_t _nodes[GNRC_IPV6_NIB_NUMOF];
+static _nib_dr_entry_t _def_routers[GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF];
+static _nib_iface_t _nis[GNRC_NETIF_NUMOF];
+
+#if ENABLE_DEBUG
+static char addr_str[IPV6_ADDR_MAX_STR_LEN];
+#endif
+
+mutex_t _nib_mutex = MUTEX_INIT;
+
+static void _override_node(const ipv6_addr_t *addr, unsigned iface,
+ _nib_onl_entry_t *node);
+static inline bool _node_unreachable(_nib_onl_entry_t *node);
+
+void _nib_init(void)
+{
+#ifdef TEST_SUITES
+ _prime_def_router = NULL;
+ _next_removable.next = NULL;
+ memset(_nodes, 0, sizeof(_nodes));
+ memset(_def_routers, 0, sizeof(_def_routers));
+ memset(_nis, 0, sizeof(_nis));
+#endif
+ /* TODO: load ABR information from persistent memory */
+}
+
+_nib_onl_entry_t *_nib_onl_alloc(const ipv6_addr_t *addr, unsigned iface)
+{
+ _nib_onl_entry_t *node = NULL;
+
+ assert(addr != NULL);
+ DEBUG("nib: Allocating on-link node entry (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)), iface);
+ for (unsigned i = 0; i < GNRC_IPV6_NIB_NUMOF; i++) {
+ _nib_onl_entry_t *tmp = &_nodes[i];
+
+ if ((_nib_onl_get_if(tmp) == iface) &&
+ (ipv6_addr_equal(addr, &tmp->ipv6))) {
+ /* exact match */
+ DEBUG(" %p is an exact match\n", (void *)tmp);
+ return tmp;
+ }
+ if ((node == NULL) && (tmp->mode == _EMPTY)) {
+ node = tmp;
+ }
+ }
+ if (node != NULL) {
+ DEBUG(" using %p\n", (void *)node);
+ _override_node(addr, iface, node);
+ }
+#if ENABLE_DEBUG
+ else {
+ DEBUG(" NIB full\n");
+ }
+#endif
+ return node;
+}
+
+static inline bool _is_gc(_nib_onl_entry_t *node)
+{
+ return ((node->mode & ~(_NC)) == 0) &&
+ ((node->info & GNRC_IPV6_NIB_NC_INFO_AR_STATE_MASK) ==
+ GNRC_IPV6_NIB_NC_INFO_AR_STATE_GC);
+}
+
+static inline _nib_onl_entry_t *_cache_out_onl_entry(const ipv6_addr_t *addr,
+ unsigned iface,
+ uint16_t cstate)
+{
+ /* Use clist as FIFO for caching */
+ _nib_onl_entry_t *first = (_nib_onl_entry_t *)clist_lpop(&_next_removable);
+ _nib_onl_entry_t *tmp = first, *res = NULL;
+
+ DEBUG("nib: Searching for replaceable entries (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)), iface);
+ if (tmp == NULL) {
+ return NULL;
+ }
+ do {
+ if (_is_gc(tmp)) {
+ DEBUG("nib: Removing neighbor cache entry (addr = %s, "
+ "iface = %u) ",
+ ipv6_addr_to_str(addr_str, &tmp->ipv6,
+ sizeof(addr_str)),
+ _nib_onl_get_if(tmp));
+ DEBUG("for (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)),
+ iface);
+ res = tmp;
+ res->mode = _EMPTY;
+ _override_node(addr, iface, res);
+ /* cstate masked above already */
+ res->info = cstate;
+ res->mode = _NC;
+ break;
+ }
+ /* requeue if not garbage collectible at the moment */
+ DEBUG("nib: Requeing (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, &tmp->ipv6,
+ sizeof(addr_str)),
+ _nib_onl_get_if(tmp));
+ clist_rpush(&_next_removable, (clist_node_t *)tmp);
+ tmp = (_nib_onl_entry_t *)clist_lpop(&_next_removable);
+ } while (tmp != first);
+ return res;
+}
+
+_nib_onl_entry_t *_nib_nc_add(const ipv6_addr_t *addr, unsigned iface,
+ uint16_t cstate)
+{
+ cstate &= GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK;
+ assert(cstate != GNRC_IPV6_NIB_NC_INFO_NUD_STATE_DELAY);
+ assert(cstate != GNRC_IPV6_NIB_NC_INFO_NUD_STATE_PROBE);
+ assert(cstate != GNRC_IPV6_NIB_NC_INFO_NUD_STATE_REACHABLE);
+ _nib_onl_entry_t *node = _nib_onl_alloc(addr, iface);
+ if (node == NULL) {
+ return _cache_out_onl_entry(addr, iface, cstate);
+ }
+ DEBUG("nib: Adding to neighbor cache (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)), iface);
+ if (!(node->mode & _NC)) {
+ node->info &= ~GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK;
+ /* masked above already */
+ node->info |= cstate;
+ node->mode |= _NC;
+ }
+ if (node->next == NULL) {
+ DEBUG("nib: queueing (addr = %s, iface = %u) for potential removal\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)), iface);
+ /* add to next removable list, if not already in it */
+ clist_rpush(&_next_removable, (clist_node_t *)node);
+ }
+ return node;
+}
+
+_nib_onl_entry_t *_nib_onl_iter(const _nib_onl_entry_t *last)
+{
+ for (const _nib_onl_entry_t *node = (last) ? last + 1 : _nodes;
+ node < (_nodes + GNRC_IPV6_NIB_NUMOF);
+ node++) {
+ if (node->mode != _EMPTY) {
+ /* const modifier provided to assure internal consistency.
+ * Can now be discarded. */
+ return (_nib_onl_entry_t *)node;
+ }
+ }
+ return NULL;
+}
+
+_nib_onl_entry_t *_nib_onl_get(const ipv6_addr_t *addr, unsigned iface)
+{
+ assert(addr != NULL);
+ DEBUG("nib: Getting on-link node entry (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)), iface);
+ for (unsigned i = 0; i < GNRC_IPV6_NIB_NUMOF; i++) {
+ _nib_onl_entry_t *node = &_nodes[i];
+
+ if ((node->mode != _EMPTY) &&
+ /* either requested or current interface undefined or
+ * interfaces equal */
+ ((_nib_onl_get_if(node) == 0) || (iface == 0) ||
+ (_nib_onl_get_if(node) == iface)) &&
+ ipv6_addr_equal(&node->ipv6, addr)) {
+ DEBUG(" Found %p\n", (void *)node);
+ return node;
+ }
+ }
+ DEBUG(" No suitable entry found\n");
+ return NULL;
+}
+
+void _nib_nc_set_reachable(_nib_onl_entry_t *node)
+{
+ _nib_iface_t *iface = _nib_iface_get(_nib_onl_get_if(node));
+
+ DEBUG("nib: set %s%%%u reachable (reachable time = %u)\n",
+ ipv6_addr_to_str(addr_str, &node->ipv6, sizeof(addr_str)),
+ _nib_onl_get_if(node), iface->reach_time);
+ node->info &= ~GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK;
+ node->info |= GNRC_IPV6_NIB_NC_INFO_NUD_STATE_REACHABLE;
+ /* TODO add event for state change to STALE to event timer*/
+ (void)iface;
+}
+
+void _nib_nc_remove(_nib_onl_entry_t *node)
+{
+ DEBUG("nib: remove from neighbor cache (addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, &node->ipv6, sizeof(addr_str)),
+ _nib_onl_get_if(node));
+ node->mode &= ~(_NC);
+ /* TODO: remove NC related timers */
+ _nib_onl_clear(node);
+}
+
+_nib_dr_entry_t *_nib_drl_add(const ipv6_addr_t *router_addr, unsigned iface)
+{
+ _nib_dr_entry_t *def_router = NULL;
+
+ DEBUG("nib: Allocating default router list entry "
+ "(router_addr = %s, iface = %u)\n",
+ ipv6_addr_to_str(addr_str, router_addr, sizeof(addr_str)), iface);
+ for (unsigned i = 0; i < GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF; i++) {
+ _nib_dr_entry_t *tmp = &_def_routers[i];
+ _nib_onl_entry_t *tmp_node = tmp->next_hop;
+
+ if ((tmp_node != NULL) &&
+ (_nib_onl_get_if(tmp_node) == iface) &&
+ (ipv6_addr_equal(router_addr, &tmp_node->ipv6))) {
+ /* exact match */
+ DEBUG(" %p is an exact match\n", (void *)tmp);
+ tmp_node->mode |= _DRL;
+ return tmp;
+ }
+ if ((def_router == NULL) && (tmp_node == NULL)) {
+ def_router = tmp;
+ }
+ }
+ if (def_router != NULL) {
+ DEBUG(" using %p\n", (void *)def_router);
+ def_router->next_hop = _nib_onl_alloc(router_addr, iface);
+
+ if (def_router->next_hop == NULL) {
+ return NULL;
+ }
+ _override_node(router_addr, iface, def_router->next_hop);
+ def_router->next_hop->mode |= _DRL;
+ }
+ return def_router;
+}
+
+void _nib_drl_remove(_nib_dr_entry_t *nib_dr)
+{
+ if (nib_dr->next_hop != NULL) {
+ nib_dr->next_hop->mode &= ~(_DRL);
+ _nib_onl_clear(nib_dr->next_hop);
+ memset(nib_dr, 0, sizeof(_nib_dr_entry_t));
+ }
+ if (nib_dr == _prime_def_router) {
+ _prime_def_router = NULL;
+ }
+}
+
+_nib_dr_entry_t *_nib_drl_iter(const _nib_dr_entry_t *last)
+{
+ for (const _nib_dr_entry_t *def_router = (last) ? (last + 1) : _def_routers;
+ def_router < (_def_routers + GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF);
+ def_router++) {
+ _nib_onl_entry_t *node = def_router->next_hop;
+ if ((node != NULL) && (node->mode != _EMPTY)) {
+ /* const modifier provided to assure internal consistency.
+ * Can now be discarded. */
+ return (_nib_dr_entry_t *)def_router;
+ }
+ }
+ return NULL;
+}
+
+_nib_dr_entry_t *_nib_drl_get(const ipv6_addr_t *router_addr, unsigned iface)
+{
+ for (unsigned i = 0; i < GNRC_IPV6_NIB_DEFAULT_ROUTER_NUMOF; i++) {
+ _nib_dr_entry_t *def_router = &_def_routers[i];
+ _nib_onl_entry_t *node = def_router->next_hop;
+
+ if ((node != NULL) &&
+ (_nib_onl_get_if(node) == iface) &&
+ (ipv6_addr_equal(router_addr, &node->ipv6))) {
+ /* It is linked to the default router list so it *should* be set */
+ assert(node->mode & _DRL);
+ return def_router;
+ }
+ }
+ return NULL;
+}
+
+_nib_dr_entry_t *_nib_drl_get_dr(void)
+{
+ _nib_dr_entry_t *ptr = NULL;
+
+ /* if there is already a default router selected or
+ * its reachability is not suspect */
+ if (!((_prime_def_router == NULL) ||
+ (_node_unreachable(_prime_def_router->next_hop)))) {
+ /* take it */
+ return _prime_def_router;
+ }
+ /* else search next reachable router */
+ do {
+ ptr = _nib_drl_iter(ptr);
+ /* if there is no reachable router */
+ if (ptr == NULL) {
+ _nib_dr_entry_t *next = _nib_drl_iter(_prime_def_router);
+ /* if first time called or last selected router is last in
+ * router list */
+ if ((_prime_def_router == NULL) || (next == NULL)) {
+ /* wrap around to first (potentially unreachable) route
+ * to trigger NUD for it */
+ _prime_def_router = _nib_drl_iter(NULL);
+ }
+ /* there is another default router, choose it regardless of
+ * reachability to potentially trigger NUD for it */
+ else if (next != NULL) {
+ _prime_def_router = next;
+ }
+ return _prime_def_router;
+ }
+ } while (_node_unreachable(ptr->next_hop));
+ _prime_def_router = ptr;
+ return _prime_def_router;
+}
+
+_nib_iface_t *_nib_iface_get(unsigned iface)
+{
+ _nib_iface_t *ni = NULL;
+
+ assert(iface <= _NIB_IF_MAX);
+ for (unsigned i = 0; i < GNRC_NETIF_NUMOF; i++) {
+ _nib_iface_t *tmp = &_nis[i];
+ if (((unsigned)tmp->pid) == iface) {
+ return tmp;
+ }
+ if ((ni == NULL) && (tmp->pid == KERNEL_PID_UNDEF)) {
+ ni = tmp;
+ }
+ }
+ if (ni != NULL) {
+ memset(ni, 0, sizeof(_nib_iface_t));
+ /* TODO: set random reachable time using constants from #6220 */
+ ni->pid = (kernel_pid_t)iface;
+ }
+ return ni;
+}
+
+static void _override_node(const ipv6_addr_t *addr, unsigned iface,
+ _nib_onl_entry_t *node)
+{
+ _nib_onl_clear(node);
+ memcpy(&node->ipv6, addr, sizeof(node->ipv6));
+ _nib_onl_set_if(node, iface);
+}
+
+static inline bool _node_unreachable(_nib_onl_entry_t *node)
+{
+ switch (node->info & GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK) {
+ case GNRC_IPV6_NIB_NC_INFO_NUD_STATE_UNREACHABLE:
+ /* Falls through. */
+ case GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/** @} */
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.h b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..980565cc1466822e865b4fc52ab512d0b4837097
--- /dev/null
+++ b/sys/net/gnrc/network_layer/ipv6/nib/_nib-internal.h
@@ -0,0 +1,633 @@
+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @addtogroup net_gnrc_ipv6_nib
+ * @internal
+ * @{
+ *
+ * @file
+ * @brief Internal definitions
+ *
+ * @author Martine Lenders <m.lenders@fu-berlin.de>
+ */
+#ifndef PRIV_NIB_INTERNAL_H
+#define PRIV_NIB_INTERNAL_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "kernel_types.h"
+#include "mutex.h"
+#include "net/eui64.h"
+#include "net/ipv6/addr.h"
+#include "net/gnrc/ipv6/nib/nc.h"
+#include "net/gnrc/ipv6/nib/conf.h"
+#include "net/gnrc/pktqueue.h"
+#include "net/ndp.h"
+#include "random.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name Mode flags for entries
+ * @anchor net_gnrc_ipv6_nib_mode
+ * @{
+ */
+#define _EMPTY (0x00) /**< empty */
+#define _NC (0x01) /**< neighbor cache */
+#define _DC (0x02) /**< destination cache */
+#define _PL (0x04) /**< prefix list */
+#define _DRL (0x08) /**< default router list */
+#define _FT (0x10) /**< forwarding table */
+#define _DAD (0x20) /**< 6LoWPAN duplicate address detection table */
+/** @} */
+
+/**
+ * @brief Shorter name for convenience ;-)
+ */
+#define _NIB_IF_MASK (GNRC_IPV6_NIB_NC_INFO_IFACE_MASK)
+
+/**
+ * @brief Shorter name for convenience ;-)
+ */
+#define _NIB_IF_POS (GNRC_IPV6_NIB_NC_INFO_IFACE_POS)
+
+/**
+ * @brief Maximum identifier for the interface
+ */
+#define _NIB_IF_MAX (_NIB_IF_MASK >> _NIB_IF_POS)
+
+/**
+ * @brief On-link NIB entry
+ * @anchor _nib_onl_entry_t
+ */
+typedef struct _nib_onl_entry {
+ struct _nib_onl_entry *next; /**< next removable entry */
+#if GNRC_IPV6_NIB_CONF_QUEUE_PKT || defined(DOXYGEN)
+ /**
+ * @brief queue for packets currently in address resolution
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_QUEUE_PKT != 0.
+ */
+ gnrc_pktqueue_t *pktqueue;
+#endif
+ /**
+ * @brief Neighbors IPv6 address
+ */
+ ipv6_addr_t ipv6;
+#if GNRC_IPV6_NIB_CONF_6LR || defined(DOXYGEN)
+ /**
+ * @brief The neighbors EUI-64 (used for DAD)
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_6LR != 0.
+ */
+ eui64_t eui64;
+#endif
+#if GNRC_IPV6_NIB_CONF_ARSM || defined(DOXYGEN)
+ /**
+ * @brief Link-layer address of _nib_onl_entry_t::next_hop
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ARSM != 0.
+ */
+ uint8_t l2addr[GNRC_IPV6_NIB_L2ADDR_MAX_LEN];
+#endif
+
+ /**
+ * @brief Information flags
+ *
+ * @see [NC info values](@ref net_gnrc_ipv6_nib_nc_info)
+ */
+ uint16_t info;
+
+ /**
+ * @brief NIB entry mode
+ *
+ * This field identifies which "views" of the NIB the entry belongs to.
+ *
+ * @see [Mode flags for entries](@ref net_gnrc_ipv6_nib_mode).
+ */
+ uint8_t mode;
+#if GNRC_IPV6_NIB_CONF_ARSM || defined(DOXYGEN)
+ /**
+ * @brief Neighbor solicitations sent for probing
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ARSM != 0.
+ */
+ uint8_t ns_sent;
+
+ /**
+ * @brief length in bytes of _nib_onl_entry_t::l2addr
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ARSM != 0.
+ */
+ uint8_t l2addr_len;
+#endif
+} _nib_onl_entry_t;
+
+/**
+ * @brief Default route NIB entry
+ */
+typedef struct {
+ _nib_onl_entry_t *next_hop; /**< next hop to destination */
+ uint16_t ltime; /**< lifetime in seconds */
+} _nib_dr_entry_t;
+
+/**
+ * @brief Off-link NIB entry
+ */
+typedef struct {
+ _nib_onl_entry_t *next_hop; /**< next hop to destination */
+ ipv6_addr_t pfx; /**< prefix to the destination */
+ unsigned pfx_len; /**< prefix-length in bits of
+ * _nib_onl_entry_t::pfx */
+} _nib_offl_entry_t;
+
+/**
+ * @brief Interface specific information for Neighbor Discovery
+ */
+typedef struct {
+#if GNRC_IPV6_NIB_CONF_ARSM
+ /**
+ * @brief base for random reachable time calculation
+ */
+ uint32_t reach_time_base;
+ uint32_t reach_time; /**< reachable time (in ms) */
+ uint32_t retrans_time; /**< retransmission time (in ms) */
+#endif
+#if GNRC_IPV6_NIB_CONF_ROUTER || defined(DOXYGEN)
+ /**
+ * @brief timestamp in milliseconds of last unsolicited router
+ * advertisement
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ROUTER.
+ */
+ uint32_t last_ra;
+#endif
+ kernel_pid_t pid; /**< identifier of the interface */
+#if GNRC_IPV6_NIB_CONF_ROUTER || defined(DOXYGEN)
+ /**
+ * @brief number of unsolicited router advertisements sent
+ *
+ * This only counts up to the first @ref NDP_MAX_INIT_RA_NUMOF on interface
+ * initialization. The last @ref NDP_MAX_FIN_RA_NUMOF of an advertising
+ * interface are counted from UINT8_MAX - @ref NDP_MAX_FIN_RA_NUMOF + 1.
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ROUTER.
+ */
+ uint8_t ra_sent;
+#endif
+ /**
+ * @brief number of unsolicited router solicitations scheduled
+ */
+ uint8_t rs_sent;
+ /**
+ * @brief number of unsolicited neighbor advertisements scheduled
+ */
+ uint8_t na_sent;
+} _nib_iface_t;
+
+/**
+ * @brief Mutex for locking the NIB
+ */
+extern mutex_t _nib_mutex;
+
+/**
+ * @brief Initializes NIB internally
+ */
+void _nib_init(void);
+
+/**
+ * @brief Gets interface identifier from a NIB entry
+ *
+ * @param[in] node A NIB entry.
+ *
+ * @return The NIB entry's interface identifier.
+ */
+static inline unsigned _nib_onl_get_if(const _nib_onl_entry_t *node)
+{
+ return (node->info & _NIB_IF_MASK) >> _NIB_IF_POS;
+}
+
+/**
+ * @brief Sets interface for a NIB entry
+ *
+ * @param[in,out] node A NIB entry.
+ * @param[in] iface An interface identifier.
+ */
+static inline void _nib_onl_set_if(_nib_onl_entry_t *node, unsigned iface)
+{
+ assert(iface <= _NIB_IF_MAX);
+ node->info &= ~(_NIB_IF_MASK);
+ node->info |= ((iface << _NIB_IF_POS) & _NIB_IF_MASK);
+}
+
+/**
+ * @brief Creates or gets an existing on-link entry by address
+ *
+ * @pre `(addr != NULL)`.
+ *
+ * @param[in] addr An IPv6 address. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to the node.
+ *
+ * @return A new or existing on-link entry with _nib_onl_entry_t::ipv6 set to
+ * @p addr.
+ * @return NULL, if no space is left.
+ */
+_nib_onl_entry_t *_nib_onl_alloc(const ipv6_addr_t *addr, unsigned iface);
+
+/**
+ * @brief Clears out a NIB entry (on-link version)
+ *
+ * @param[in,out] node An entry.
+ *
+ * @return true, if entry was cleared.
+ * @return false, if entry was not cleared.
+ */
+static inline bool _nib_onl_clear(_nib_onl_entry_t *node)
+{
+ if (node->mode == _EMPTY) {
+ memset(node, 0, sizeof(_nib_onl_entry_t));
+ return true;
+ }
+ return false;
+}
+
+/**
+ * @brief Iterates over on-link entries
+ *
+ * @param[in] last Last entry (NULL to start).
+ *
+ * @return entry after @p last.
+ */
+_nib_onl_entry_t *_nib_onl_iter(const _nib_onl_entry_t *last);
+
+/**
+ * @brief Gets a node by IPv6 address and interface
+ *
+ * @pre `(addr != NULL)`
+ *
+ * @param[in] addr The address of a node. May not be NULL.
+ * @param[in] iface The interface to the node. May be 0 for any interface.
+ *
+ * @return The NIB entry for node with @p addr and @p iface on success.
+ * @return NULL, if there is no such entry.
+ */
+_nib_onl_entry_t *_nib_onl_get(const ipv6_addr_t *addr, unsigned iface);
+
+/**
+ * @brief Creates or gets an existing node from the neighbor cache by address
+ *
+ * @pre `(addr != NULL)`
+ * @pre `((cstate & GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK) !=
+ * GNRC_IPV6_NIB_NC_INFO_NUD_STATE_DELAY)`
+ * @pre `((cstate & GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK) !=
+ * GNRC_IPV6_NIB_NC_INFO_NUD_STATE_PROBE)`
+ * @pre `((cstate & GNRC_IPV6_NIB_NC_INFO_NUD_STATE_MASK) !=
+ * GNRC_IPV6_NIB_NC_INFO_NUD_STATE_REACHABLE)`
+ *
+ * @param[in] addr The address of a node. May not be NULL.
+ * @param[in] iface The interface to the node.
+ * @param[in] cstate Creation state. State of the entry *if* the entry is
+ * newly created.
+ *
+ * @return The NIB entry for the new neighbor cache entry on success.
+ * @return NULL, if there is no space left.
+ */
+_nib_onl_entry_t *_nib_nc_add(const ipv6_addr_t *addr, unsigned iface,
+ uint16_t cstate);
+
+/**
+ * @brief Removes a node from the neighbor cache
+ *
+ * @param[in,out] node A node.
+ */
+void _nib_nc_remove(_nib_onl_entry_t *node);
+
+/**
+ * @brief Sets a NUD-managed neighbor cache entry to reachable and sets the
+ * respective event in @ref _nib_evtimer "event timer"
+ * (@ref GNRC_IPV6_NIB_MSG_NUD_SET_STALE)
+ *
+ * @param[in,out] node A node.
+ */
+void _nib_nc_set_reachable(_nib_onl_entry_t *node);
+
+/**
+ * @brief Creates or gets an existing node from the DAD table by address
+ *
+ * @pre `addr != NULL`
+ *
+ * @param[in] addr The address of a node. May not be NULL.
+ *
+ * @return The NIB entry for the new DAD table entry on success.
+ * @return NULL, if there is no space left.
+ */
+static inline _nib_onl_entry_t *_nib_dad_add(const ipv6_addr_t *addr)
+{
+ _nib_onl_entry_t *node = _nib_onl_alloc(addr, 0);
+
+ if (node != NULL) {
+ node->mode |= (_DAD);
+ }
+ return node;
+}
+
+/**
+ * @brief Removes a node from the DAD table
+ *
+ * @param[in] node A node.
+ */
+static inline void _nib_dad_remove(_nib_onl_entry_t *node)
+{
+ node->mode &= ~(_DAD);
+ _nib_onl_clear(node);
+}
+
+/**
+ * @brief Creates or gets an existing default router list entry by address
+ *
+ * @pre `(router_addr != NULL)`
+ *
+ * @param[in] addr An IPv6 address. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to the router.
+ *
+ * @return A new or existing default router entry with _nib_onl_entry_t::ipv6
+ * of _nib_dr_entry_t::next_hop set to @p router_addr.
+ * @return NULL, if no space is left.
+ */
+_nib_dr_entry_t *_nib_drl_add(const ipv6_addr_t *router_addr, unsigned iface);
+
+/**
+ * @brief Removes a default router list entry
+ *
+ * @param[in,out] nib_dr An entry.
+ *
+ * Corresponding on-link entry is removed, too.
+ */
+void _nib_drl_remove(_nib_dr_entry_t *nib_dr);
+
+/**
+ * @brief Iterates over default router list
+ *
+ * @param[in] last Last entry (NULL to start).
+ *
+ * @return entry after @p last.
+ */
+_nib_dr_entry_t *_nib_drl_iter(const _nib_dr_entry_t *last);
+
+/**
+ * @brief Gets a default router by IPv6 address and interface
+ *
+ * @pre `(router_addr != NULL)`
+ *
+ * @param[in] router_addr The address of a default router. May not be NULL.
+ * @param[in] iface The interface to the node. May be 0 for any
+ * interface.
+ *
+ * @return The NIB entry for node with @p router_addr and @p iface onsuccess.
+ * @return NULL, if there is no such entry.
+ */
+_nib_dr_entry_t *_nib_drl_get(const ipv6_addr_t *router_addr, unsigned iface);
+
+/**
+ * @brief Gets *the* default router
+ *
+ * @see [RFC 4861, section 6.3.6](https://tools.ietf.org/html/rfc4861#section-6.3.6)
+ *
+ * @return The current default router, on success.
+ * @return NULL, if there is no default router in the list.
+ */
+_nib_dr_entry_t *_nib_drl_get_dr(void);
+
+/**
+ * @brief Creates or gets an existing off-link entry by next hop and prefix
+ *
+ * @pre `(next_hop != NULL)`
+ * @pre `(pfx != NULL) && (pfx != "::") && (pfx_len != 0) && (pfx_len <= 128)`
+ *
+ * @param[in] next_hop An IPv6 address to next hop. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to @p next_hop.
+ * @param[in] pfx The IPv6 prefix or address of the destination.
+ * May not be NULL or unspecified address. Use
+ * @ref _nib_drl_add() for default route destinations.
+ * @param[in] pfx_len The length in bits of @p pfx in bits.
+ *
+ * @return A new or existing off-link entry with _nib_dr_entry_t::pfx set to
+ * @p pfx.
+ * @return NULL, if no space is left.
+ */
+_nib_offl_entry_t *_nib_dst_alloc(const ipv6_addr_t *next_hop, unsigned iface,
+ const ipv6_addr_t *pfx, unsigned pfx_len);
+
+/**
+ * @brief Clears out a NIB entry (off-link version)
+ *
+ * @param[in,out] dst An entry.
+ */
+void _nib_dst_clear(_nib_offl_entry_t *dst);
+
+/**
+ * @brief Iterates over off-link entries
+ *
+ * @param[in] last Last entry (NULL to start).
+ *
+ * @return entry after @p last.
+ */
+_nib_offl_entry_t *_nib_dst_iter(const _nib_offl_entry_t *last);
+
+/**
+ * @brief Helper function for view-level add-functions below
+ *
+ * @pre `(next_hop != NULL)`
+ * @pre `(pfx != NULL) && (pfx != "::") && (pfx_len != 0) && (pfx_len <= 128)`
+ *
+ * @param[in] next_hop Next hop to the destination. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to the destination.
+ * @param[in] pfx The IPv6 prefix or address of the destination.
+ * May not be NULL or unspecified address. Use
+ * @ref _nib_drl_add() for default route destinations.
+ * @param[in] pfx_len The length in bits of @p pfx in bits.
+ * @param[in] mode [NIB-mode](_nib_onl_entry_t::mode).
+ *
+ * @return A new or existing off-link entry with _nib_dr_entry_t::pfx set to
+ * @p pfx.
+ * @return NULL, if no space is left.
+ */
+static inline _nib_offl_entry_t *_nib_dst_add(const ipv6_addr_t *next_hop,
+ unsigned iface,
+ const ipv6_addr_t *pfx,
+ unsigned pfx_len, uint8_t mode)
+{
+ _nib_offl_entry_t *nib_offl = _nib_dst_alloc(next_hop, iface, pfx, pfx_len);
+
+ if (nib_offl != NULL) {
+ nib_offl->next_hop->mode |= (mode);
+ }
+ return nib_offl;
+}
+
+/**
+ * @brief Helper function for the view-level remove-functions below
+ *
+ * @param[in,out] nib_offl An entry.
+ */
+static inline void _nib_dst_remove(_nib_offl_entry_t *nib_offl, uint8_t mode)
+{
+ _nib_onl_entry_t *node = nib_offl->next_hop;
+
+ if (node != NULL) {
+ node->mode &= ~mode;
+ }
+ _nib_dst_clear(nib_offl);
+}
+
+#if defined(GNRC_IPV6_NIB_CONF_DC) || DOXYGEN
+/**
+ * @brief Creates or gets an existing destination cache entry by its addresses
+ *
+ * @pre `(next_hop != NULL)`
+ * @pre `(dst != NULL)`
+ *
+ * @param[in] next_hop Next hop to the destination. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to the destination.
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_DC.
+ *
+ * @return A new or existing destination cache entry with
+ * _nib_onl_entry_t::ipv6 of _nib_dr_entry_t::next_hop set to
+ * @p next_hop.
+ * @return NULL, if no space is left.
+ */
+static inline _nib_offl_entry_t *_nib_dc_add(const ipv6_addr_t *next_hop,
+ unsigned iface,
+ const ipv6_addr_t *dst)
+{
+ return _nib_dst_add(next_hop, iface, dst, IPV6_ADDR_BIT_LEN, _DC);
+}
+
+/**
+ * @brief Removes a destination cache entry
+ *
+ * @param[in,out] nib_dr An entry.
+ *
+ * Corresponding on-link entry is removed, too.
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_DC.
+ */
+static inline void _nib_dc_remove(_nib_offl_entry_t *nib_offl)
+{
+ _nib_dst_remove(nib_offl, _DC);
+}
+#endif /* GNRC_IPV6_NIB_CONF_DC */
+
+/**
+ * @brief Creates or gets an existing prefix list entry by its prefix
+ *
+ * @pre `(next_hop != NULL)`
+ * @pre `(pfx != NULL) && (pfx != "::") && (pfx_len != 0) && (pfx_len <= 128)`
+ *
+ * @param[in] iface The interface to the prefix is added to.
+ * @param[in] pfx The IPv6 prefix or address of the destination.
+ * May not be NULL or unspecified address. Use
+ * @ref _nib_drl_add() for default route destinations.
+ * @param[in] pfx_len The length in bits of @p pfx in bits.
+ *
+ * @return A new or existing prefix list entry with _nib_dr_entry_t::pfx set to
+ * @p pfx.
+ * @return NULL, if no space is left.
+ */
+static inline _nib_offl_entry_t *_nib_pl_add(unsigned iface,
+ const ipv6_addr_t *pfx,
+ unsigned pfx_len)
+{
+ return _nib_dst_add(NULL, iface, pfx, pfx_len, _PL);
+}
+
+/**
+ * @brief Removes a prefix list entry
+ *
+ * @param[in,out] nib_offl An entry.
+ *
+ * Corresponding on-link entry is removed, too.
+ */
+static inline void _nib_pl_remove(_nib_offl_entry_t *nib_offl)
+{
+ _nib_dst_remove(nib_offl, _PL);
+}
+
+#if defined(GNRC_IPV6_NIB_CONF_ROUTER) || DOXYGEN
+/**
+ * @brief Creates or gets an existing forwarding table entry by its prefix
+ *
+ * @pre `(next_hop != NULL)`
+ * @pre `(pfx != NULL) && (pfx != "::") && (pfx_len != 0) && (pfx_len <= 128)`
+ *
+ * @param[in] next_hop Next hop to the destination. May not be NULL.
+ * *May also be a global address!*
+ * @param[in] iface The interface to the destination.
+ * @param[in] pfx The IPv6 prefix or address of the destination.
+ * May not be NULL or unspecified address. Use
+ * @ref _nib_drl_add() for default route destinations.
+ * @param[in] pfx_len The length in bits of @p pfx in bits.
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ROUTER.
+ *
+ * @return A new or existing forwarding table entry with _nib_dr_entry_t::pfx
+ * set to @p pfx.
+ * @return NULL, if no space is left.
+ */
+static inline _nib_offl_entry_t *_nib_ft_add(const ipv6_addr_t *next_hop,
+ unsigned iface,
+ const ipv6_addr_t *pfx,
+ unsigned pfx_len)
+{
+ return _nib_dst_add(next_hop, iface, pfx, pfx_len, _FT);
+}
+
+/**
+ * @brief Removes a forwarding table entry
+ *
+ * @param[in,out] nib_offl An entry.
+ *
+ * Corresponding on-link entry is removed, too.
+ *
+ * @note Only available if @ref GNRC_IPV6_NIB_CONF_ROUTER.
+ */
+static inline void _nib_ft_remove(_nib_offl_entry_t *nib_offl)
+{
+ _nib_dst_remove(nib_offl, _FT);
+}
+#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
+
+/**
+ * @brief Gets (or creates if it not exists) interface information for
+ * neighbor discovery
+ *
+ * @pre `(iface <= _NIB_IF_MAX)`
+ *
+ * @param[in] iface Interface identifier to get information for.
+ *
+ * @return Interface information on @p iface.
+ * @return NULL, if no space left for interface.
+ */
+_nib_iface_t *_nib_iface_get(unsigned iface);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PRIV_NIB_INTERNAL_H */
+/** @} */