Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1327 insertions, 0 deletions

diff --git a/ospf6d/ospf6_neighbor.c b/ospf6d/ospf6_neighbor.c
new file mode 100644
index 0000000..e1aec06
--- /dev/null
+++ b/ospf6d/ospf6_neighbor.c
@@ -0,0 +1,1327 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2003 Yasuhiro Ohara
+ */
+
+#include <zebra.h>
+
+#include "log.h"
+#include "memory.h"
+#include "frrevent.h"
+#include "linklist.h"
+#include "vty.h"
+#include "command.h"
+#include "lib/bfd.h"
+
+#include "ospf6_proto.h"
+#include "ospf6_lsa.h"
+#include "ospf6_lsdb.h"
+#include "ospf6_message.h"
+#include "ospf6_top.h"
+#include "ospf6_area.h"
+#include "ospf6_interface.h"
+#include "ospf6_neighbor.h"
+#include "ospf6_intra.h"
+#include "ospf6_flood.h"
+#include "ospf6d.h"
+#include "ospf6_bfd.h"
+#include "ospf6_abr.h"
+#include "ospf6_asbr.h"
+#include "ospf6_lsa.h"
+#include "ospf6_spf.h"
+#include "ospf6_zebra.h"
+#include "ospf6_gr.h"
+#include "lib/json.h"
+
+DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_NEIGHBOR, "OSPF6 neighbor");
+
+DEFINE_HOOK(ospf6_neighbor_change,
+	    (struct ospf6_neighbor * on, int state, int next_state),
+	    (on, state, next_state));
+
+unsigned char conf_debug_ospf6_neighbor = 0;
+
+const char *const ospf6_neighbor_state_str[] = {
+	"None",    "Down",     "Attempt", "Init", "Twoway",
+	"ExStart", "ExChange", "Loading", "Full", NULL};
+
+const char *const ospf6_neighbor_event_str[] = {
+	"NoEvent",      "HelloReceived", "2-WayReceived",   "NegotiationDone",
+	"ExchangeDone", "LoadingDone",   "AdjOK?",	  "SeqNumberMismatch",
+	"BadLSReq",     "1-WayReceived", "InactivityTimer",
+};
+
+int ospf6_neighbor_cmp(void *va, void *vb)
+{
+	struct ospf6_neighbor *ona = (struct ospf6_neighbor *)va;
+	struct ospf6_neighbor *onb = (struct ospf6_neighbor *)vb;
+
+	if (ona->router_id == onb->router_id)
+		return 0;
+
+	return (ntohl(ona->router_id) < ntohl(onb->router_id)) ? -1 : 1;
+}
+
+struct ospf6_neighbor *ospf6_neighbor_lookup(uint32_t router_id,
+					     struct ospf6_interface *oi)
+{
+	struct listnode *n;
+	struct ospf6_neighbor *on;
+
+	for (ALL_LIST_ELEMENTS_RO(oi->neighbor_list, n, on))
+		if (on->router_id == router_id)
+			return on;
+
+	return (struct ospf6_neighbor *)NULL;
+}
+
+struct ospf6_neighbor *ospf6_area_neighbor_lookup(struct ospf6_area *area,
+						  uint32_t router_id)
+{
+	struct ospf6_interface *oi;
+	struct ospf6_neighbor *nbr;
+	struct listnode *node;
+
+	for (ALL_LIST_ELEMENTS_RO(area->if_list, node, oi)) {
+		nbr = ospf6_neighbor_lookup(router_id, oi);
+		if (nbr)
+			return nbr;
+	}
+
+	return NULL;
+}
+
+static void ospf6_neighbor_clear_ls_lists(struct ospf6_neighbor *on)
+{
+	struct ospf6_lsa *lsa;
+	struct ospf6_lsa *lsanext;
+
+	ospf6_lsdb_remove_all(on->summary_list);
+	if (on->last_ls_req) {
+		ospf6_lsa_unlock(&on->last_ls_req);
+		on->last_ls_req = NULL;
+	}
+
+	ospf6_lsdb_remove_all(on->request_list);
+	for (ALL_LSDB(on->retrans_list, lsa, lsanext)) {
+		ospf6_decrement_retrans_count(lsa);
+		ospf6_lsdb_remove(lsa, on->retrans_list);
+	}
+}
+
+/* create ospf6_neighbor */
+struct ospf6_neighbor *ospf6_neighbor_create(uint32_t router_id,
+					     struct ospf6_interface *oi)
+{
+	struct ospf6_neighbor *on;
+	char buf[16];
+	int type;
+
+	on = XCALLOC(MTYPE_OSPF6_NEIGHBOR, sizeof(struct ospf6_neighbor));
+	inet_ntop(AF_INET, &router_id, buf, sizeof(buf));
+	snprintf(on->name, sizeof(on->name), "%s%%%s", buf,
+		 oi->interface->name);
+	on->ospf6_if = oi;
+	on->state = OSPF6_NEIGHBOR_DOWN;
+	on->state_change = 0;
+	monotime(&on->last_changed);
+	on->router_id = router_id;
+
+	on->summary_list = ospf6_lsdb_create(on);
+	on->request_list = ospf6_lsdb_create(on);
+	on->retrans_list = ospf6_lsdb_create(on);
+
+	on->dbdesc_list = ospf6_lsdb_create(on);
+	on->lsupdate_list = ospf6_lsdb_create(on);
+	on->lsack_list = ospf6_lsdb_create(on);
+
+	for (type = 0; type < OSPF6_MESSAGE_TYPE_MAX; type++) {
+		on->seqnum_l[type] = 0;
+		on->seqnum_h[type] = 0;
+	}
+
+	on->auth_present = false;
+
+	listnode_add_sort(oi->neighbor_list, on);
+
+	ospf6_bfd_info_nbr_create(oi, on);
+	return on;
+}
+
+void ospf6_neighbor_delete(struct ospf6_neighbor *on)
+{
+	ospf6_neighbor_clear_ls_lists(on);
+
+	ospf6_lsdb_remove_all(on->dbdesc_list);
+	ospf6_lsdb_remove_all(on->lsupdate_list);
+	ospf6_lsdb_remove_all(on->lsack_list);
+
+	ospf6_lsdb_delete(on->summary_list);
+	ospf6_lsdb_delete(on->request_list);
+	ospf6_lsdb_delete(on->retrans_list);
+
+	ospf6_lsdb_delete(on->dbdesc_list);
+	ospf6_lsdb_delete(on->lsupdate_list);
+	ospf6_lsdb_delete(on->lsack_list);
+
+	EVENT_OFF(on->inactivity_timer);
+
+	EVENT_OFF(on->last_dbdesc_release_timer);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	EVENT_OFF(on->thread_send_lsreq);
+	EVENT_OFF(on->thread_send_lsupdate);
+	EVENT_OFF(on->thread_send_lsack);
+	EVENT_OFF(on->thread_exchange_done);
+	EVENT_OFF(on->thread_adj_ok);
+	EVENT_OFF(on->event_loading_done);
+
+	EVENT_OFF(on->gr_helper_info.t_grace_timer);
+
+	bfd_sess_free(&on->bfd_session);
+	XFREE(MTYPE_OSPF6_NEIGHBOR, on);
+}
+
+static void ospf6_neighbor_state_change(uint8_t next_state,
+					struct ospf6_neighbor *on, int event)
+{
+	uint8_t prev_state;
+
+	prev_state = on->state;
+	on->state = next_state;
+
+	if (prev_state == next_state)
+		return;
+
+	on->state_change++;
+	monotime(&on->last_changed);
+
+	/* log */
+	if (IS_OSPF6_DEBUG_NEIGHBOR(STATE)) {
+		zlog_debug(
+			"Neighbor state change %s (Router-ID: %pI4): [%s]->[%s] (%s)",
+			on->name, &on->router_id,
+			ospf6_neighbor_state_str[prev_state],
+			ospf6_neighbor_state_str[next_state],
+			ospf6_neighbor_event_string(event));
+	}
+
+	/* Optionally notify about adjacency changes */
+	if (CHECK_FLAG(on->ospf6_if->area->ospf6->config_flags,
+		       OSPF6_LOG_ADJACENCY_CHANGES)
+	    && (CHECK_FLAG(on->ospf6_if->area->ospf6->config_flags,
+			   OSPF6_LOG_ADJACENCY_DETAIL)
+		|| (next_state == OSPF6_NEIGHBOR_FULL)
+		|| (next_state < prev_state)))
+		zlog_notice(
+			"AdjChg: Nbr %pI4(%s) on %s: %s -> %s (%s)",
+			&on->router_id,
+			vrf_id_to_name(on->ospf6_if->interface->vrf->vrf_id),
+			on->name, ospf6_neighbor_state_str[prev_state],
+			ospf6_neighbor_state_str[next_state],
+			ospf6_neighbor_event_string(event));
+
+	if (prev_state == OSPF6_NEIGHBOR_FULL
+	    || next_state == OSPF6_NEIGHBOR_FULL) {
+		if (!OSPF6_GR_IS_ACTIVE_HELPER(on)) {
+			OSPF6_ROUTER_LSA_SCHEDULE(on->ospf6_if->area);
+			if (on->ospf6_if->state == OSPF6_INTERFACE_DR) {
+				OSPF6_NETWORK_LSA_SCHEDULE(on->ospf6_if);
+				OSPF6_INTRA_PREFIX_LSA_SCHEDULE_TRANSIT(
+					on->ospf6_if);
+			}
+		}
+		if (next_state == OSPF6_NEIGHBOR_FULL)
+			on->ospf6_if->area->intra_prefix_originate = 1;
+
+		if (!OSPF6_GR_IS_ACTIVE_HELPER(on))
+			OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB(
+				on->ospf6_if->area);
+
+		if ((prev_state == OSPF6_NEIGHBOR_LOADING
+		     || prev_state == OSPF6_NEIGHBOR_EXCHANGE)
+		    && next_state == OSPF6_NEIGHBOR_FULL) {
+			OSPF6_AS_EXTERN_LSA_SCHEDULE(on->ospf6_if);
+			on->ospf6_if->area->full_nbrs++;
+		}
+
+		if (prev_state == OSPF6_NEIGHBOR_FULL)
+			on->ospf6_if->area->full_nbrs--;
+	}
+
+	if ((prev_state == OSPF6_NEIGHBOR_EXCHANGE
+	     || prev_state == OSPF6_NEIGHBOR_LOADING)
+	    && (next_state != OSPF6_NEIGHBOR_EXCHANGE
+		&& next_state != OSPF6_NEIGHBOR_LOADING))
+		ospf6_maxage_remove(on->ospf6_if->area->ospf6);
+
+	hook_call(ospf6_neighbor_change, on, next_state, prev_state);
+	ospf6_bfd_trigger_event(on, prev_state, next_state);
+}
+
+/* RFC2328 section 10.4 */
+static int need_adjacency(struct ospf6_neighbor *on)
+{
+	if (on->ospf6_if->state == OSPF6_INTERFACE_POINTTOPOINT
+	    || on->ospf6_if->state == OSPF6_INTERFACE_DR
+	    || on->ospf6_if->state == OSPF6_INTERFACE_BDR)
+		return 1;
+
+	if (on->ospf6_if->drouter == on->router_id
+	    || on->ospf6_if->bdrouter == on->router_id)
+		return 1;
+
+	return 0;
+}
+
+void hello_received(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *HelloReceived*", on->name);
+
+	/* reset Inactivity Timer */
+	EVENT_OFF(on->inactivity_timer);
+	event_add_timer(master, inactivity_timer, on,
+			on->ospf6_if->dead_interval, &on->inactivity_timer);
+
+	if (on->state <= OSPF6_NEIGHBOR_DOWN)
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_INIT, on,
+					    OSPF6_NEIGHBOR_EVENT_HELLO_RCVD);
+}
+
+void twoway_received(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state > OSPF6_NEIGHBOR_INIT)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *2Way-Received*", on->name);
+
+	event_add_event(master, neighbor_change, on->ospf6_if, 0, NULL);
+
+	if (!need_adjacency(on)) {
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_TWOWAY, on,
+					    OSPF6_NEIGHBOR_EVENT_TWOWAY_RCVD);
+		return;
+	}
+
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_EXSTART, on,
+				    OSPF6_NEIGHBOR_EVENT_TWOWAY_RCVD);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	event_add_event(master, ospf6_dbdesc_send, on, 0,
+			&on->thread_send_dbdesc);
+}
+
+void negotiation_done(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+	struct ospf6_lsa *lsa, *lsanext;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state != OSPF6_NEIGHBOR_EXSTART)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *NegotiationDone*", on->name);
+
+	/* clear ls-list */
+	ospf6_neighbor_clear_ls_lists(on);
+
+	/* Interface scoped LSAs */
+	for (ALL_LSDB(on->ospf6_if->lsdb, lsa, lsanext)) {
+		if (OSPF6_LSA_IS_MAXAGE(lsa)) {
+			ospf6_increment_retrans_count(lsa);
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->retrans_list);
+		} else
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->summary_list);
+	}
+
+	/* Area scoped LSAs */
+	for (ALL_LSDB(on->ospf6_if->area->lsdb, lsa, lsanext)) {
+		if (OSPF6_LSA_IS_MAXAGE(lsa)) {
+			ospf6_increment_retrans_count(lsa);
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->retrans_list);
+		} else
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->summary_list);
+	}
+
+	/* AS scoped LSAs */
+	for (ALL_LSDB(on->ospf6_if->area->ospf6->lsdb, lsa, lsanext)) {
+		if (OSPF6_LSA_IS_MAXAGE(lsa)) {
+			ospf6_increment_retrans_count(lsa);
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->retrans_list);
+		} else
+			ospf6_lsdb_add(ospf6_lsa_copy(lsa), on->summary_list);
+	}
+
+	UNSET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT);
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_EXCHANGE, on,
+				    OSPF6_NEIGHBOR_EVENT_NEGOTIATION_DONE);
+}
+
+static void ospf6_neighbor_last_dbdesc_release(struct event *thread)
+{
+	struct ospf6_neighbor *on = EVENT_ARG(thread);
+
+	assert(on);
+	memset(&on->dbdesc_last, 0, sizeof(struct ospf6_dbdesc));
+}
+
+void exchange_done(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state != OSPF6_NEIGHBOR_EXCHANGE)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *ExchangeDone*", on->name);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	ospf6_lsdb_remove_all(on->dbdesc_list);
+
+	/* RFC 2328 (10.8): Release the last dbdesc after dead_interval */
+	if (!CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT)) {
+		EVENT_OFF(on->last_dbdesc_release_timer);
+		event_add_timer(master, ospf6_neighbor_last_dbdesc_release, on,
+				on->ospf6_if->dead_interval,
+				&on->last_dbdesc_release_timer);
+	}
+
+	if (on->request_list->count == 0)
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_FULL, on,
+					    OSPF6_NEIGHBOR_EVENT_EXCHANGE_DONE);
+	else {
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_LOADING, on,
+					    OSPF6_NEIGHBOR_EVENT_EXCHANGE_DONE);
+
+		event_add_event(master, ospf6_lsreq_send, on, 0,
+				&on->thread_send_lsreq);
+	}
+}
+
+/* Check loading state. */
+void ospf6_check_nbr_loading(struct ospf6_neighbor *on)
+{
+
+	/* RFC2328 Section 10.9: When the neighbor responds to these requests
+	   with the proper Link State Update packet(s), the Link state request
+	   list is truncated and a new Link State Request packet is sent.
+	*/
+	if ((on->state == OSPF6_NEIGHBOR_LOADING)
+	    || (on->state == OSPF6_NEIGHBOR_EXCHANGE)) {
+		if (on->request_list->count == 0)
+			event_add_event(master, loading_done, on, 0,
+					&on->event_loading_done);
+		else if (on->last_ls_req == NULL) {
+			EVENT_OFF(on->thread_send_lsreq);
+			event_add_event(master, ospf6_lsreq_send, on, 0,
+					&on->thread_send_lsreq);
+		}
+	}
+}
+
+void loading_done(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state != OSPF6_NEIGHBOR_LOADING)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *LoadingDone*", on->name);
+
+	assert(on->request_list->count == 0);
+
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_FULL, on,
+				    OSPF6_NEIGHBOR_EVENT_LOADING_DONE);
+}
+
+void adj_ok(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *AdjOK?*", on->name);
+
+	if (on->state == OSPF6_NEIGHBOR_TWOWAY && need_adjacency(on)) {
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_EXSTART, on,
+					    OSPF6_NEIGHBOR_EVENT_ADJ_OK);
+		SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT);
+		SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT);
+		SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT);
+
+		EVENT_OFF(on->thread_send_dbdesc);
+		event_add_event(master, ospf6_dbdesc_send, on, 0,
+				&on->thread_send_dbdesc);
+
+	} else if (on->state >= OSPF6_NEIGHBOR_EXSTART && !need_adjacency(on)) {
+		ospf6_neighbor_state_change(OSPF6_NEIGHBOR_TWOWAY, on,
+					    OSPF6_NEIGHBOR_EVENT_ADJ_OK);
+		ospf6_neighbor_clear_ls_lists(on);
+	}
+}
+
+void seqnumber_mismatch(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state < OSPF6_NEIGHBOR_EXCHANGE)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *SeqNumberMismatch*", on->name);
+
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_EXSTART, on,
+				    OSPF6_NEIGHBOR_EVENT_SEQNUMBER_MISMATCH);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT);
+
+	ospf6_neighbor_clear_ls_lists(on);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	on->dbdesc_seqnum++; /* Incr seqnum as per RFC2328, sec 10.3 */
+
+	event_add_event(master, ospf6_dbdesc_send, on, 0,
+			&on->thread_send_dbdesc);
+}
+
+void bad_lsreq(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state < OSPF6_NEIGHBOR_EXCHANGE)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *BadLSReq*", on->name);
+
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_EXSTART, on,
+				    OSPF6_NEIGHBOR_EVENT_BAD_LSREQ);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT);
+	SET_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT);
+
+	ospf6_neighbor_clear_ls_lists(on);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	on->dbdesc_seqnum++; /* Incr seqnum as per RFC2328, sec 10.3 */
+
+	event_add_event(master, ospf6_dbdesc_send, on, 0,
+			&on->thread_send_dbdesc);
+}
+
+void oneway_received(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (on->state < OSPF6_NEIGHBOR_TWOWAY)
+		return;
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *1Way-Received*", on->name);
+
+	ospf6_neighbor_state_change(OSPF6_NEIGHBOR_INIT, on,
+				    OSPF6_NEIGHBOR_EVENT_ONEWAY_RCVD);
+	event_add_event(master, neighbor_change, on->ospf6_if, 0, NULL);
+
+	ospf6_neighbor_clear_ls_lists(on);
+
+	EVENT_OFF(on->thread_send_dbdesc);
+	EVENT_OFF(on->thread_send_lsreq);
+	EVENT_OFF(on->thread_send_lsupdate);
+	EVENT_OFF(on->thread_send_lsack);
+	EVENT_OFF(on->thread_exchange_done);
+	EVENT_OFF(on->thread_adj_ok);
+}
+
+void inactivity_timer(struct event *thread)
+{
+	struct ospf6_neighbor *on;
+
+	on = (struct ospf6_neighbor *)EVENT_ARG(thread);
+	assert(on);
+
+	if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		zlog_debug("Neighbor Event %s: *InactivityTimer*", on->name);
+
+	on->drouter = on->prev_drouter = 0;
+	on->bdrouter = on->prev_bdrouter = 0;
+
+	if (!OSPF6_GR_IS_ACTIVE_HELPER(on)) {
+		on->drouter = on->prev_drouter = 0;
+		on->bdrouter = on->prev_bdrouter = 0;
+
+		ospf6_neighbor_state_change(
+			OSPF6_NEIGHBOR_DOWN, on,
+			OSPF6_NEIGHBOR_EVENT_INACTIVITY_TIMER);
+		event_add_event(master, neighbor_change, on->ospf6_if, 0, NULL);
+
+		listnode_delete(on->ospf6_if->neighbor_list, on);
+		ospf6_neighbor_delete(on);
+
+	} else {
+		if (IS_DEBUG_OSPF6_GR)
+			zlog_debug(
+				"%s, Acting as HELPER for this neighbour, So restart the dead timer.",
+				__PRETTY_FUNCTION__);
+
+		event_add_timer(master, inactivity_timer, on,
+				on->ospf6_if->dead_interval,
+				&on->inactivity_timer);
+	}
+}
+
+
+/* vty functions */
+/* show neighbor structure */
+static void ospf6_neighbor_show(struct vty *vty, struct ospf6_neighbor *on,
+				json_object *json_array, bool use_json)
+{
+	char router_id[16];
+	char duration[64];
+	struct timeval res;
+	char nstate[16];
+	char deadtime[64];
+	long h, m, s;
+	json_object *json_route;
+
+	/* Router-ID (Name) */
+	inet_ntop(AF_INET, &on->router_id, router_id, sizeof(router_id));
+#ifdef HAVE_GETNAMEINFO
+	{
+	}
+#endif /*HAVE_GETNAMEINFO*/
+
+	/* Dead time */
+	h = m = s = 0;
+	if (on->inactivity_timer) {
+		s = monotime_until(&on->inactivity_timer->u.sands, NULL)
+		    / 1000000LL;
+		h = s / 3600;
+		s -= h * 3600;
+		m = s / 60;
+		s -= m * 60;
+	}
+	snprintf(deadtime, sizeof(deadtime), "%02ld:%02ld:%02ld", h, m, s);
+
+	/* Neighbor State */
+	if (on->ospf6_if->type == OSPF_IFTYPE_POINTOPOINT)
+		snprintf(nstate, sizeof(nstate), "PointToPoint");
+	else {
+		if (on->router_id == on->drouter)
+			snprintf(nstate, sizeof(nstate), "DR");
+		else if (on->router_id == on->bdrouter)
+			snprintf(nstate, sizeof(nstate), "BDR");
+		else
+			snprintf(nstate, sizeof(nstate), "DROther");
+	}
+
+	/* Duration */
+	monotime_since(&on->last_changed, &res);
+	timerstring(&res, duration, sizeof(duration));
+
+	/*
+	vty_out (vty, "%-15s %3d %11s %6s/%-12s %11s %s[%s]\n",
+		 "Neighbor ID", "Pri", "DeadTime", "State", "IfState",
+	"Duration", "I/F", "State");
+	*/
+	if (use_json) {
+		json_route = json_object_new_object();
+
+		json_object_string_add(json_route, "neighborId", router_id);
+		json_object_int_add(json_route, "priority", on->priority);
+		json_object_string_add(json_route, "deadTime", deadtime);
+		json_object_string_add(json_route, "state",
+				       ospf6_neighbor_state_str[on->state]);
+		json_object_string_add(json_route, "ifState", nstate);
+		json_object_string_add(json_route, "duration", duration);
+		json_object_string_add(json_route, "interfaceName",
+				       on->ospf6_if->interface->name);
+		json_object_string_add(
+			json_route, "interfaceState",
+			ospf6_interface_state_str[on->ospf6_if->state]);
+
+		json_object_array_add(json_array, json_route);
+	} else
+		vty_out(vty, "%-15s %3d %11s %8s/%-12s %11s %s[%s]\n",
+			router_id, on->priority, deadtime,
+			ospf6_neighbor_state_str[on->state], nstate, duration,
+			on->ospf6_if->interface->name,
+			ospf6_interface_state_str[on->ospf6_if->state]);
+}
+
+static void ospf6_neighbor_show_drchoice(struct vty *vty,
+					 struct ospf6_neighbor *on,
+					 json_object *json_array, bool use_json)
+{
+	char router_id[16];
+	char drouter[16], bdrouter[16];
+	char duration[64];
+	struct timeval now, res;
+	json_object *json_route;
+
+	/*
+	    vty_out (vty, "%-15s %6s/%-11s %-15s %-15s %s[%s]\n",
+		     "RouterID", "State", "Duration", "DR", "BDR", "I/F",
+		     "State");
+	*/
+
+	inet_ntop(AF_INET, &on->router_id, router_id, sizeof(router_id));
+	inet_ntop(AF_INET, &on->drouter, drouter, sizeof(drouter));
+	inet_ntop(AF_INET, &on->bdrouter, bdrouter, sizeof(bdrouter));
+
+	monotime(&now);
+	timersub(&now, &on->last_changed, &res);
+	timerstring(&res, duration, sizeof(duration));
+
+	if (use_json) {
+		json_route = json_object_new_object();
+		json_object_string_add(json_route, "routerId", router_id);
+		json_object_string_add(json_route, "state",
+				       ospf6_neighbor_state_str[on->state]);
+		json_object_string_add(json_route, "duration", duration);
+		json_object_string_add(json_route, "dRouter", drouter);
+		json_object_string_add(json_route, "bdRouter", bdrouter);
+		json_object_string_add(json_route, "interfaceName",
+				       on->ospf6_if->interface->name);
+		json_object_string_add(
+			json_route, "interfaceState",
+			ospf6_interface_state_str[on->ospf6_if->state]);
+
+		json_object_array_add(json_array, json_route);
+	} else
+		vty_out(vty, "%-15s %8s/%-11s %-15s %-15s %s[%s]\n", router_id,
+			ospf6_neighbor_state_str[on->state], duration, drouter,
+			bdrouter, on->ospf6_if->interface->name,
+			ospf6_interface_state_str[on->ospf6_if->state]);
+}
+
+static void ospf6_neighbor_show_detail(struct vty *vty,
+				       struct ospf6_neighbor *on,
+				       json_object *json, bool use_json)
+{
+	char drouter[16], bdrouter[16];
+	char linklocal_addr[64], duration[32];
+	struct timeval now, res;
+	struct ospf6_lsa *lsa, *lsanext;
+	json_object *json_neighbor;
+	json_object *json_array;
+	char db_desc_str[20];
+
+	inet_ntop(AF_INET6, &on->linklocal_addr, linklocal_addr,
+		  sizeof(linklocal_addr));
+	inet_ntop(AF_INET, &on->drouter, drouter, sizeof(drouter));
+	inet_ntop(AF_INET, &on->bdrouter, bdrouter, sizeof(bdrouter));
+
+	monotime(&now);
+	timersub(&now, &on->last_changed, &res);
+	timerstring(&res, duration, sizeof(duration));
+
+	if (use_json) {
+		json_neighbor = json_object_new_object();
+		json_object_string_add(json_neighbor, "area",
+				       on->ospf6_if->area->name);
+		json_object_string_add(json_neighbor, "interface",
+				       on->ospf6_if->interface->name);
+		json_object_int_add(json_neighbor, "interfaceIndex",
+				    on->ospf6_if->interface->ifindex);
+		json_object_int_add(json_neighbor, "neighborInterfaceIndex",
+				    on->ifindex);
+		json_object_string_add(json_neighbor, "linkLocalAddress",
+				       linklocal_addr);
+		json_object_string_add(json_neighbor, "neighborState",
+				       ospf6_neighbor_state_str[on->state]);
+		json_object_string_add(json_neighbor, "neighborStateDuration",
+				       duration);
+		json_object_string_add(json_neighbor, "neighborDRouter",
+				       drouter);
+		json_object_string_add(json_neighbor, "neighborBdRouter",
+				       bdrouter);
+		snprintf(db_desc_str, sizeof(db_desc_str), "%s%s%s",
+			 (CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT)
+				  ? "Initial "
+				  : ""),
+			 (CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT)
+				  ? "More"
+				  : ""),
+			 (CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT)
+				  ? "Master"
+				  : "Slave"));
+		json_object_string_add(json_neighbor, "dbDescStatus",
+				       db_desc_str);
+
+		json_object_int_add(json_neighbor, "dbDescSeqNumber",
+				    (unsigned long)ntohl(on->dbdesc_seqnum));
+
+		json_array = json_object_new_array();
+		json_object_int_add(json_neighbor, "summaryListCount",
+				    on->summary_list->count);
+		for (ALL_LSDB(on->summary_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "summaryListLsa",
+				       json_array);
+
+		json_array = json_object_new_array();
+		json_object_int_add(json_neighbor, "requestListCount",
+				    on->request_list->count);
+		for (ALL_LSDB(on->request_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "requestListLsa",
+				       json_array);
+
+		json_array = json_object_new_array();
+		json_object_int_add(json_neighbor, "reTransListCount",
+				    on->retrans_list->count);
+		for (ALL_LSDB(on->retrans_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "reTransListLsa",
+				       json_array);
+
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_dbdesc))
+			timersub(&on->thread_send_dbdesc->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		json_object_int_add(json_neighbor, "pendingLsaDbDescCount",
+				    on->dbdesc_list->count);
+		json_object_string_add(json_neighbor, "pendingLsaDbDescTime",
+				       duration);
+		json_object_string_add(
+			json_neighbor, "dbDescSendThread",
+			(event_is_scheduled(on->thread_send_dbdesc) ? "on"
+								    : "off"));
+		json_array = json_object_new_array();
+		for (ALL_LSDB(on->dbdesc_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "pendingLsaDbDesc",
+				       json_array);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsreq))
+			timersub(&on->thread_send_lsreq->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		json_object_int_add(json_neighbor, "pendingLsaLsReqCount",
+				    on->request_list->count);
+		json_object_string_add(json_neighbor, "pendingLsaLsReqTime",
+				       duration);
+		json_object_string_add(
+			json_neighbor, "lsReqSendThread",
+			(event_is_scheduled(on->thread_send_lsreq) ? "on"
+								   : "off"));
+		json_array = json_object_new_array();
+		for (ALL_LSDB(on->request_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "pendingLsaLsReq",
+				       json_array);
+
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsupdate))
+			timersub(&on->thread_send_lsupdate->u.sands, &now,
+				 &res);
+		timerstring(&res, duration, sizeof(duration));
+		json_object_int_add(json_neighbor, "pendingLsaLsUpdateCount",
+				    on->lsupdate_list->count);
+		json_object_string_add(json_neighbor, "pendingLsaLsUpdateTime",
+				       duration);
+		json_object_string_add(
+			json_neighbor, "lsUpdateSendThread",
+			(event_is_scheduled(on->thread_send_lsupdate) ? "on"
+								      : "off"));
+		json_array = json_object_new_array();
+		for (ALL_LSDB(on->lsupdate_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "pendingLsaLsUpdate",
+				       json_array);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsack))
+			timersub(&on->thread_send_lsack->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		json_object_int_add(json_neighbor, "pendingLsaLsAckCount",
+				    on->lsack_list->count);
+		json_object_string_add(json_neighbor, "pendingLsaLsAckTime",
+				       duration);
+		json_object_string_add(
+			json_neighbor, "lsAckSendThread",
+			(event_is_scheduled(on->thread_send_lsack) ? "on"
+								   : "off"));
+		json_array = json_object_new_array();
+		for (ALL_LSDB(on->lsack_list, lsa, lsanext))
+			json_object_array_add(
+				json_array, json_object_new_string(lsa->name));
+		json_object_object_add(json_neighbor, "pendingLsaLsAck",
+				       json_array);
+
+		bfd_sess_show(vty, json_neighbor, on->bfd_session);
+
+		if (on->auth_present == true) {
+			json_object_string_add(json_neighbor, "authStatus",
+					       "enabled");
+			json_object_int_add(
+				json_neighbor, "recvdHelloHigherSeqNo",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_HELLO]);
+			json_object_int_add(
+				json_neighbor, "recvdHelloLowerSeqNo",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_HELLO]);
+			json_object_int_add(
+				json_neighbor, "recvdDBDescHigherSeqNo",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_DBDESC]);
+			json_object_int_add(
+				json_neighbor, "recvdDBDescLowerSeqNo",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_DBDESC]);
+			json_object_int_add(
+				json_neighbor, "recvdLSReqHigherSeqNo",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSREQ]);
+			json_object_int_add(
+				json_neighbor, "recvdLSReqLowerSeqNo",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSREQ]);
+			json_object_int_add(
+				json_neighbor, "recvdLSUpdHigherSeqNo",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSUPDATE]);
+			json_object_int_add(
+				json_neighbor, "recvdLSUpdLowerSeqNo",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSUPDATE]);
+			json_object_int_add(
+				json_neighbor, "recvdLSAckHigherSeqNo",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSACK]);
+			json_object_int_add(
+				json_neighbor, "recvdLSAckLowerSeqNo",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSACK]);
+		} else
+			json_object_string_add(json_neighbor, "authStatus",
+					       "disabled");
+
+		json_object_object_add(json, on->name, json_neighbor);
+
+	} else {
+		vty_out(vty, " Neighbor %s\n", on->name);
+		vty_out(vty, "    Area %s via interface %s (ifindex %d)\n",
+			on->ospf6_if->area->name, on->ospf6_if->interface->name,
+			on->ospf6_if->interface->ifindex);
+		vty_out(vty, "    His IfIndex: %d Link-local address: %s\n",
+			on->ifindex, linklocal_addr);
+		vty_out(vty, "    State %s for a duration of %s\n",
+			ospf6_neighbor_state_str[on->state], duration);
+		vty_out(vty, "    His choice of DR/BDR %s/%s, Priority %d\n",
+			drouter, bdrouter, on->priority);
+		vty_out(vty, "    DbDesc status: %s%s%s SeqNum: %#lx\n",
+			(CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT)
+				 ? "Initial "
+				 : ""),
+			(CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MBIT)
+				 ? "More "
+				 : ""),
+			(CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_MSBIT)
+				 ? "Master"
+				 : "Slave"),
+			(unsigned long)ntohl(on->dbdesc_seqnum));
+
+		vty_out(vty, "    Summary-List: %d LSAs\n",
+			on->summary_list->count);
+		for (ALL_LSDB(on->summary_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		vty_out(vty, "    Request-List: %d LSAs\n",
+			on->request_list->count);
+		for (ALL_LSDB(on->request_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		vty_out(vty, "    Retrans-List: %d LSAs\n",
+			on->retrans_list->count);
+		for (ALL_LSDB(on->retrans_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_dbdesc))
+			timersub(&on->thread_send_dbdesc->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		vty_out(vty,
+			"    %d Pending LSAs for DbDesc in Time %s [thread %s]\n",
+			on->dbdesc_list->count, duration,
+			(event_is_scheduled(on->thread_send_dbdesc) ? "on"
+								    : "off"));
+		for (ALL_LSDB(on->dbdesc_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsreq))
+			timersub(&on->thread_send_lsreq->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		vty_out(vty,
+			"    %d Pending LSAs for LSReq in Time %s [thread %s]\n",
+			on->request_list->count, duration,
+			(event_is_scheduled(on->thread_send_lsreq) ? "on"
+								   : "off"));
+		for (ALL_LSDB(on->request_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsupdate))
+			timersub(&on->thread_send_lsupdate->u.sands, &now,
+				 &res);
+		timerstring(&res, duration, sizeof(duration));
+		vty_out(vty,
+			"    %d Pending LSAs for LSUpdate in Time %s [thread %s]\n",
+			on->lsupdate_list->count, duration,
+			(event_is_scheduled(on->thread_send_lsupdate) ? "on"
+								      : "off"));
+		for (ALL_LSDB(on->lsupdate_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		timerclear(&res);
+		if (event_is_scheduled(on->thread_send_lsack))
+			timersub(&on->thread_send_lsack->u.sands, &now, &res);
+		timerstring(&res, duration, sizeof(duration));
+		vty_out(vty,
+			"    %d Pending LSAs for LSAck in Time %s [thread %s]\n",
+			on->lsack_list->count, duration,
+			(event_is_scheduled(on->thread_send_lsack) ? "on"
+								   : "off"));
+		for (ALL_LSDB(on->lsack_list, lsa, lsanext))
+			vty_out(vty, "      %s\n", lsa->name);
+
+		bfd_sess_show(vty, NULL, on->bfd_session);
+
+		if (on->auth_present == true) {
+			vty_out(vty, "    Authentication header present\n");
+			vty_out(vty,
+				"\t\t\t hello        DBDesc       LSReq        LSUpd        LSAck\n");
+			vty_out(vty,
+				"      Higher sequence no 0x%-10X 0x%-10X 0x%-10X 0x%-10X 0x%-10X\n",
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_HELLO],
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_DBDESC],
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSREQ],
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSUPDATE],
+				on->seqnum_h[OSPF6_MESSAGE_TYPE_LSACK]);
+			vty_out(vty,
+				"      Lower sequence no  0x%-10X 0x%-10X 0x%-10X 0x%-10X 0x%-10X\n",
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_HELLO],
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_DBDESC],
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSREQ],
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSUPDATE],
+				on->seqnum_l[OSPF6_MESSAGE_TYPE_LSACK]);
+		} else
+			vty_out(vty, "    Authentication header not present\n");
+	}
+}
+
+static void ospf6_neighbor_show_detail_common(struct vty *vty,
+					      struct ospf6 *ospf6, bool uj,
+					      bool detail, bool drchoice)
+{
+	struct ospf6_neighbor *on;
+	struct ospf6_interface *oi;
+	struct ospf6_area *oa;
+	struct listnode *i, *j, *k;
+	json_object *json = NULL;
+	json_object *json_array = NULL;
+	void (*showfunc)(struct vty *, struct ospf6_neighbor *,
+			 json_object *json, bool use_json);
+
+	if (detail)
+		showfunc = ospf6_neighbor_show_detail;
+	else if (drchoice)
+		showfunc = ospf6_neighbor_show_drchoice;
+	else
+		showfunc = ospf6_neighbor_show;
+
+	if (uj) {
+		json = json_object_new_object();
+		json_array = json_object_new_array();
+	} else {
+		if (showfunc == ospf6_neighbor_show)
+			vty_out(vty, "%-15s %3s %11s %8s/%-12s %11s %s[%s]\n",
+				"Neighbor ID", "Pri", "DeadTime", "State",
+				"IfState", "Duration", "I/F", "State");
+		else if (showfunc == ospf6_neighbor_show_drchoice)
+			vty_out(vty, "%-15s %8s/%-11s %-15s %-15s %s[%s]\n",
+				"RouterID", "State", "Duration", "DR", "BDR",
+				"I/F", "State");
+	}
+
+	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, i, oa))
+		for (ALL_LIST_ELEMENTS_RO(oa->if_list, j, oi))
+			for (ALL_LIST_ELEMENTS_RO(oi->neighbor_list, k, on)) {
+				if (showfunc == ospf6_neighbor_show_detail)
+					(*showfunc)(vty, on, json, uj);
+				else
+					(*showfunc)(vty, on, json_array, uj);
+			}
+
+	if (uj) {
+		if (showfunc != ospf6_neighbor_show_detail)
+			json_object_object_add(json, "neighbors", json_array);
+		else
+			json_object_free(json_array);
+		vty_json(vty, json);
+	}
+}
+
+DEFUN(show_ipv6_ospf6_neighbor, show_ipv6_ospf6_neighbor_cmd,
+      "show ipv6 ospf6 [vrf <NAME|all>] neighbor [<detail|drchoice>] [json]",
+      SHOW_STR IP6_STR OSPF6_STR VRF_CMD_HELP_STR
+      "All VRFs\n"
+      "Neighbor list\n"
+      "Display details\n"
+      "Display DR choices\n" JSON_STR)
+{
+	struct ospf6 *ospf6;
+	struct listnode *node;
+	const char *vrf_name = NULL;
+	bool all_vrf = false;
+	int idx_vrf = 0;
+	int idx_type = 4;
+	bool uj = use_json(argc, argv);
+	bool detail = false;
+	bool drchoice = false;
+
+	OSPF6_FIND_VRF_ARGS(argv, argc, idx_vrf, vrf_name, all_vrf);
+
+	if (argv_find(argv, argc, "detail", &idx_type))
+		detail = true;
+	else if (argv_find(argv, argc, "drchoice", &idx_type))
+		drchoice = true;
+
+	for (ALL_LIST_ELEMENTS_RO(om6->ospf6, node, ospf6)) {
+		if (all_vrf || strcmp(ospf6->name, vrf_name) == 0) {
+			ospf6_neighbor_show_detail_common(vty, ospf6, uj,
+							  detail, drchoice);
+			if (!all_vrf)
+				break;
+		}
+	}
+
+	OSPF6_CMD_CHECK_VRF(uj, all_vrf, ospf6);
+
+	return CMD_SUCCESS;
+}
+
+static int ospf6_neighbor_show_common(struct vty *vty, int argc,
+				      struct cmd_token **argv,
+				      struct ospf6 *ospf6, int idx_ipv4,
+				      bool uj)
+{
+	struct ospf6_neighbor *on;
+	struct ospf6_interface *oi;
+	struct ospf6_area *oa;
+	struct listnode *i, *j, *k;
+	void (*showfunc)(struct vty *, struct ospf6_neighbor *,
+			 json_object *json, bool use_json);
+	uint32_t router_id;
+	json_object *json = NULL;
+
+	showfunc = ospf6_neighbor_show_detail;
+	if (uj)
+		json = json_object_new_object();
+
+	if ((inet_pton(AF_INET, argv[idx_ipv4]->arg, &router_id)) != 1) {
+		vty_out(vty, "Router-ID is not parsable: %s\n",
+			argv[idx_ipv4]->arg);
+		return CMD_SUCCESS;
+	}
+
+	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, i, oa))
+		for (ALL_LIST_ELEMENTS_RO(oa->if_list, j, oi))
+			for (ALL_LIST_ELEMENTS_RO(oi->neighbor_list, k, on)) {
+				if (router_id == on->router_id)
+					(*showfunc)(vty, on, json, uj);
+			}
+
+	if (uj)
+		vty_json(vty, json);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(show_ipv6_ospf6_neighbor_one, show_ipv6_ospf6_neighbor_one_cmd,
+      "show ipv6 ospf6 [vrf <NAME|all>] neighbor A.B.C.D [json]",
+      SHOW_STR IP6_STR OSPF6_STR VRF_CMD_HELP_STR
+      "All VRFs\n"
+      "Neighbor list\n"
+      "Specify Router-ID as IPv4 address notation\n" JSON_STR)
+{
+	int idx_ipv4 = 4;
+	struct ospf6 *ospf6;
+	struct listnode *node;
+	const char *vrf_name = NULL;
+	bool all_vrf = false;
+	int idx_vrf = 0;
+	bool uj = use_json(argc, argv);
+
+	OSPF6_FIND_VRF_ARGS(argv, argc, idx_vrf, vrf_name, all_vrf);
+	if (idx_vrf > 0)
+		idx_ipv4 += 2;
+
+	for (ALL_LIST_ELEMENTS_RO(om6->ospf6, node, ospf6)) {
+		if (all_vrf || strcmp(ospf6->name, vrf_name) == 0) {
+			ospf6_neighbor_show_common(vty, argc, argv, ospf6,
+						   idx_ipv4, uj);
+
+			if (!all_vrf)
+				break;
+		}
+	}
+
+	OSPF6_CMD_CHECK_VRF(uj, all_vrf, ospf6);
+
+	return CMD_SUCCESS;
+}
+
+void ospf6_neighbor_init(void)
+{
+	install_element(VIEW_NODE, &show_ipv6_ospf6_neighbor_cmd);
+	install_element(VIEW_NODE, &show_ipv6_ospf6_neighbor_one_cmd);
+}
+
+DEFUN (debug_ospf6_neighbor,
+       debug_ospf6_neighbor_cmd,
+       "debug ospf6 neighbor [<state|event>]",
+       DEBUG_STR
+       OSPF6_STR
+       "Debug OSPFv3 Neighbor\n"
+       "Debug OSPFv3 Neighbor State Change\n"
+       "Debug OSPFv3 Neighbor Event\n")
+{
+	int idx_type = 3;
+	unsigned char level = 0;
+
+	if (argc == 4) {
+		if (!strncmp(argv[idx_type]->arg, "s", 1))
+			level = OSPF6_DEBUG_NEIGHBOR_STATE;
+		else if (!strncmp(argv[idx_type]->arg, "e", 1))
+			level = OSPF6_DEBUG_NEIGHBOR_EVENT;
+	} else
+		level = OSPF6_DEBUG_NEIGHBOR_STATE | OSPF6_DEBUG_NEIGHBOR_EVENT;
+
+	OSPF6_DEBUG_NEIGHBOR_ON(level);
+	return CMD_SUCCESS;
+}
+
+
+DEFUN (no_debug_ospf6_neighbor,
+       no_debug_ospf6_neighbor_cmd,
+       "no debug ospf6 neighbor [<state|event>]",
+       NO_STR
+       DEBUG_STR
+       OSPF6_STR
+       "Debug OSPFv3 Neighbor\n"
+       "Debug OSPFv3 Neighbor State Change\n"
+       "Debug OSPFv3 Neighbor Event\n")
+{
+	int idx_type = 4;
+	unsigned char level = 0;
+
+	if (argc == 5) {
+		if (!strncmp(argv[idx_type]->arg, "s", 1))
+			level = OSPF6_DEBUG_NEIGHBOR_STATE;
+		if (!strncmp(argv[idx_type]->arg, "e", 1))
+			level = OSPF6_DEBUG_NEIGHBOR_EVENT;
+	} else
+		level = OSPF6_DEBUG_NEIGHBOR_STATE | OSPF6_DEBUG_NEIGHBOR_EVENT;
+
+	OSPF6_DEBUG_NEIGHBOR_OFF(level);
+	return CMD_SUCCESS;
+}
+
+
+DEFUN (no_debug_ospf6,
+       no_debug_ospf6_cmd,
+       "no debug ospf6",
+       NO_STR
+       DEBUG_STR
+       OSPF6_STR)
+{
+	unsigned int i;
+
+	OSPF6_DEBUG_ABR_OFF();
+	OSPF6_DEBUG_ASBR_OFF();
+	OSPF6_DEBUG_BROUTER_OFF();
+	OSPF6_DEBUG_BROUTER_SPECIFIC_ROUTER_OFF();
+	OSPF6_DEBUG_BROUTER_SPECIFIC_AREA_OFF();
+	OSPF6_DEBUG_FLOODING_OFF();
+	OSPF6_DEBUG_INTERFACE_OFF();
+
+	ospf6_lsa_debug_set_all(false);
+
+	for (i = 0; i < 6; i++)
+		OSPF6_DEBUG_MESSAGE_OFF(i,
+					OSPF6_DEBUG_NEIGHBOR_STATE
+						| OSPF6_DEBUG_NEIGHBOR_EVENT);
+
+	OSPF6_DEBUG_NEIGHBOR_OFF(OSPF6_DEBUG_NEIGHBOR_STATE
+				 | OSPF6_DEBUG_NEIGHBOR_EVENT);
+	OSPF6_DEBUG_ROUTE_OFF(OSPF6_DEBUG_ROUTE_TABLE);
+	OSPF6_DEBUG_ROUTE_OFF(OSPF6_DEBUG_ROUTE_INTRA);
+	OSPF6_DEBUG_ROUTE_OFF(OSPF6_DEBUG_ROUTE_INTER);
+	OSPF6_DEBUG_ROUTE_OFF(OSPF6_DEBUG_ROUTE_MEMORY);
+	OSPF6_DEBUG_SPF_OFF(OSPF6_DEBUG_SPF_PROCESS);
+	OSPF6_DEBUG_SPF_OFF(OSPF6_DEBUG_SPF_TIME);
+	OSPF6_DEBUG_SPF_OFF(OSPF6_DEBUG_SPF_DATABASE);
+	OSPF6_DEBUG_ZEBRA_OFF(OSPF6_DEBUG_ZEBRA_SEND | OSPF6_DEBUG_ZEBRA_RECV);
+
+	return CMD_SUCCESS;
+}
+
+int config_write_ospf6_debug_neighbor(struct vty *vty)
+{
+	if (IS_OSPF6_DEBUG_NEIGHBOR(STATE) && IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		vty_out(vty, "debug ospf6 neighbor\n");
+	else if (IS_OSPF6_DEBUG_NEIGHBOR(STATE))
+		vty_out(vty, "debug ospf6 neighbor state\n");
+	else if (IS_OSPF6_DEBUG_NEIGHBOR(EVENT))
+		vty_out(vty, "debug ospf6 neighbor event\n");
+	return 0;
+}
+
+void install_element_ospf6_debug_neighbor(void)
+{
+	install_element(ENABLE_NODE, &debug_ospf6_neighbor_cmd);
+	install_element(ENABLE_NODE, &no_debug_ospf6_neighbor_cmd);
+	install_element(ENABLE_NODE, &no_debug_ospf6_cmd);
+	install_element(CONFIG_NODE, &debug_ospf6_neighbor_cmd);
+	install_element(CONFIG_NODE, &no_debug_ospf6_neighbor_cmd);
+	install_element(CONFIG_NODE, &no_debug_ospf6_cmd);
+}