ospf6d: Stitching the auth trailer code with rest of ospf6.

Problem Statement:
==================
RFC 7166 support for OSPF6 in FRR code.

RCA:
====
This feature is newly supported in FRR

Fix:
====
Core functionality implemented in previous commit is
stitched with rest of ospf6 code as part of this commit.

Risk:
=====
Low risk

Tests Executed:
===============
Have executed the combination of commands.

Signed-off-by: Abhinay Ramesh <rabhinay@vmware.com>

15 files changed, 698 insertions, 263 deletions

diff --git a/ospf6d/ospf6_auth_trailer.c b/ospf6d/ospf6_auth_trailer.c
index 88d2fc240..2d0621cc2 100644
--- a/ospf6d/ospf6_auth_trailer.c
+++ b/ospf6d/ospf6_auth_trailer.c
@@ -19,6 +19,7 @@
  */
 
 #include "zebra.h"
+#include "config.h"
 #include "memory.h"
 #include "ospf6d.h"
 #include "vty.h"
@@ -30,14 +31,14 @@
 #include "ospf6_interface.h"
 #include "ospf6_neighbor.h"
 #include "ospf6_proto.h"
+#include "ospf6_top.h"
+#include "ospf6_area.h"
 #include "ospf6_auth_trailer.h"
 #include "ospf6_route.h"
 #include "ospf6_zebra.h"
 #include "lib/keychain.h"
 
 unsigned char conf_debug_ospf6_auth[2];
-DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_AUTH_PKT, "OSPF6 auth packet");
-DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_AUTH_HASH, "OSPF6 auth hash");
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_AUTH_HASH_XOR, "OSPF6 auth hash xor");
 
 /*Apad is the hexadecimal value 0x878FE1F3. */
@@ -106,17 +107,18 @@ void ospf6_auth_hdr_dump_send(struct ospf6_header *ospfh, uint16_t length)
 	}
 }
 
-void ospf6_auth_hdr_dump_recv(struct ospf6_header *ospfh, uint16_t length)
+void ospf6_auth_hdr_dump_recv(struct ospf6_header *ospfh, uint16_t length,
+			      unsigned int lls_len)
 {
 	struct ospf6_auth_hdr *ospf6_at_hdr;
 	int at_len, oh_len, at_hdr_len, hash_len;
-	unsigned char temp[KEYCHAIN_MAX_HASH_SIZE+1];
+	unsigned char temp[KEYCHAIN_MAX_HASH_SIZE + 1];
 
 	oh_len = ntohs(ospfh->length);
-	at_len = length - oh_len;
+	at_len = length - (oh_len + lls_len);
 	if (at_len > 0) {
-		ospf6_at_hdr = (struct ospf6_auth_hdr *)
-					((uint8_t *)ospfh + oh_len);
+		ospf6_at_hdr =
+			(struct ospf6_auth_hdr *)((uint8_t *)ospfh + oh_len);
 		at_hdr_len = ntohs(ospf6_at_hdr->length);
 		hash_len = at_hdr_len - OSPF6_AUTH_HDR_MIN_SIZE;
 		memcpy(temp, ospf6_at_hdr->data, hash_len);
@@ -312,7 +314,8 @@ unsigned int ospf6_auth_len_get(struct ospf6_interface *oi)
 }
 
 int ospf6_auth_validate_pkt(struct ospf6_interface *oi, unsigned int *pkt_len,
-			    struct ospf6_header *oh, unsigned int *at_len)
+			    struct ospf6_header *oh, unsigned int *at_len,
+			    unsigned int *lls_block_len)
 {
 	struct ospf6_hello *hello = NULL;
 	struct ospf6_dbdesc *dbdesc = NULL;
@@ -321,132 +324,146 @@ int ospf6_auth_validate_pkt(struct ospf6_interface *oi, unsigned int *pkt_len,
 	uint16_t hdr_len = 0;
 	uint32_t oh_seqnum_h = 0;
 	uint32_t oh_seqnum_l = 0;
+	bool auth_present = false;
+	bool lls_present = false;
+	struct ospf6_lls_hdr *lls_hdr = NULL;
 
 	on = ospf6_neighbor_lookup(oh->router_id, oi);
 	hdr_len = ntohs(oh->length);
 	if (*pkt_len < hdr_len) {
 		if (IS_OSPF6_DEBUG_AUTH_RX)
-			zlog_warn("RECV[%s] Wrong %s packet auth length",
-				  oi->interface->name,
-				  lookup_msg(ospf6_message_type_str, oh->type,
-					     NULL));
-		oi->at_data.rx_drop++;
-		return -1;
+			zlog_err("RECV[%s] Received incomplete %s packet",
+				 oi->interface->name,
+				 ospf6_message_type(oh->type));
+		return OSPF6_AUTH_VALIDATE_FAILURE;
 	} else if (*pkt_len == hdr_len) {
-		/* no auth data in packet
+		if (oi->at_data.flags != 0)
+			return OSPF6_AUTH_VALIDATE_FAILURE;
+		/* No auth info to be considered.
 		 */
-		return -1;
+		return OSPF6_AUTH_PROCESS_NORMAL;
 	}
 
 	switch (oh->type) {
 	case OSPF6_MESSAGE_TYPE_HELLO:
 		hello = (struct ospf6_hello *)((uint8_t *)oh
 					       + sizeof(struct ospf6_header));
-		if (OSPF6_OPT_ISSET_EXT(hello->options, OSPF6_OPT_AT)) {
-			if (on)
-				on->auth_present = true;
-		} else {
-			if (on)
-				on->auth_present = false;
-
-			if (oi->at_data.flags != 0) {
-				if (IS_OSPF6_DEBUG_AUTH_RX)
-					zlog_warn("RECV[%s] : Auth option miss-match in hello pkt",
-						  oi->interface->name);
-				oi->at_data.rx_drop++;
-			}
+		if (OSPF6_OPT_ISSET_EXT(hello->options, OSPF6_OPT_L))
+			lls_present = true;
 
-			return -1;
-		}
+		if (OSPF6_OPT_ISSET_EXT(hello->options, OSPF6_OPT_AT))
+			auth_present = true;
 		break;
 	case OSPF6_MESSAGE_TYPE_DBDESC:
 		dbdesc = (struct ospf6_dbdesc *)((uint8_t *)oh
 						 + sizeof(struct ospf6_header));
+		if (OSPF6_OPT_ISSET_EXT(dbdesc->options, OSPF6_OPT_L))
+			lls_present = true;
 
-		if (OSPF6_OPT_ISSET_EXT(dbdesc->options, OSPF6_OPT_AT)) {
-			if (on)
-				on->auth_present = true;
-		} else {
-			if (on)
-				on->auth_present = false;
-
-			if (oi->at_data.flags != 0) {
-				if (IS_OSPF6_DEBUG_AUTH_RX)
-					zlog_warn("RECV[%s] : Auth option miss-match in DB desc pkt",
-						  oi->interface->name);
-				oi->at_data.rx_drop++;
-			}
-
-			return -1;
-		}
+		if (OSPF6_OPT_ISSET_EXT(dbdesc->options, OSPF6_OPT_AT))
+			auth_present = true;
 		break;
 	case OSPF6_MESSAGE_TYPE_LSREQ:
 	case OSPF6_MESSAGE_TYPE_LSUPDATE:
 	case OSPF6_MESSAGE_TYPE_LSACK:
-		if ((on && on->auth_present == false)
-		    && (oi->at_data.flags != 0)) {
-			if (IS_OSPF6_DEBUG_AUTH_RX)
-				zlog_warn("RECV[%s] : Auth config miss-match in %s",
-					  oi->interface->name,
-					  lookup_msg(ospf6_message_type_str,
-						     oh->type, NULL));
-			oi->at_data.rx_drop++;
-			return -1;
+		if (on) {
+			lls_present = on->lls_present;
+			auth_present = on->auth_present;
 		}
 		break;
 	default:
 		if (IS_OSPF6_DEBUG_AUTH_RX)
-			zlog_warn("RECV[%s] : Wrong packet type %d",
-				  oi->interface->name, oh->type);
-		return -1;
+			zlog_err("RECV[%s] : Wrong packet type %d",
+				 oi->interface->name, oh->type);
+		return OSPF6_AUTH_VALIDATE_FAILURE;
+	}
+
+	if ((oh->type == OSPF6_MESSAGE_TYPE_HELLO)
+	    || (oh->type == OSPF6_MESSAGE_TYPE_DBDESC)) {
+		if (on) {
+			on->auth_present = auth_present;
+			on->lls_present = lls_present;
+		}
+	}
+
+	if ((!auth_present && (oi->at_data.flags != 0))
+	    || (auth_present && (oi->at_data.flags == 0))) {
+		if (IS_OSPF6_DEBUG_AUTH_RX)
+			zlog_err("RECV[%s] : Auth option miss-match in %s pkt",
+				 oi->interface->name,
+				 ospf6_message_type(oh->type));
+		return OSPF6_AUTH_VALIDATE_FAILURE;
+	}
+
+	if (lls_present) {
+		lls_hdr = (struct ospf6_lls_hdr *)(oh + hdr_len);
+		*lls_block_len = ntohs(lls_hdr->length) * 4;
+	}
+
+	if (*lls_block_len > (*pkt_len - hdr_len)) {
+		if (IS_OSPF6_DEBUG_AUTH_RX)
+			zlog_err("RECV[%s] : Wrong lls data in %s packet",
+				 oi->interface->name,
+				 ospf6_message_type(oh->type));
+		return OSPF6_AUTH_VALIDATE_FAILURE;
 	}
 
 	memset(&ospf6_auth_info, 0, sizeof(struct ospf6_auth_hdr));
-	memcpy(&ospf6_auth_info, (uint8_t *)oh + hdr_len, *pkt_len - hdr_len);
+	if ((*pkt_len - hdr_len - (*lls_block_len)) > sizeof(ospf6_auth_info)) {
+		if (IS_OSPF6_DEBUG_AUTH_RX)
+			zlog_err("RECV[%s] : Wrong auth data in %s packet",
+				 oi->interface->name,
+				 ospf6_message_type(oh->type));
+		return OSPF6_AUTH_VALIDATE_FAILURE;
+	}
+
+	memcpy(&ospf6_auth_info, ((uint8_t *)oh + hdr_len + (*lls_block_len)),
+	       (*pkt_len - hdr_len - (*lls_block_len)));
 	if (ntohs(ospf6_auth_info.length) > OSPF6_AUTH_HDR_FULL) {
 		if (IS_OSPF6_DEBUG_AUTH_RX)
-			zlog_warn("RECV[%s] : Auth config miss-match in %s",
-				  oi->interface->name,
-				  lookup_msg(ospf6_message_type_str, oh->type,
-					     NULL));
-		oi->at_data.rx_drop++;
-		return -1;
+			zlog_err("RECV[%s] : Wrong auth header length in %s",
+				 oi->interface->name,
+				 ospf6_message_type(oh->type));
+		return OSPF6_AUTH_VALIDATE_FAILURE;
 	}
 
 	/* after authentication header validation is done
 	 * reduce the auth hdr size from the packet length
 	 */
 	*at_len = ntohs(ospf6_auth_info.length);
-	*pkt_len = *pkt_len - *at_len;
+	*pkt_len = (*pkt_len) - (*at_len) - (*lls_block_len);
 
 	if (on) {
 		oh_seqnum_h = ntohl(ospf6_auth_info.seqnum_h);
 		oh_seqnum_l = ntohl(ospf6_auth_info.seqnum_l);
-		if ((oh_seqnum_h >= on->seqnum_h) &&
-		     (oh_seqnum_l > on->seqnum_l)) {
+		if ((oh_seqnum_h >= on->seqnum_h[oh->type])
+		    && (oh_seqnum_l > on->seqnum_l[oh->type])) {
 			/* valid sequence number received */
-			on->seqnum_h = oh_seqnum_h;
-			on->seqnum_l = oh_seqnum_l;
+			on->seqnum_h[oh->type] = oh_seqnum_h;
+			on->seqnum_l[oh->type] = oh_seqnum_l;
 		} else {
 			if (IS_OSPF6_DEBUG_AUTH_RX) {
-				zlog_warn("RECV[%s] : Nbr(%s) Auth Sequence number mismatch",
-					  oi->interface->name, on->name);
-				zlog_warn("nbr_seq_l %u, nbr_seq_h %u, hdr_seq_l %u, hdr_seq_h %u",
-					  on->seqnum_l, on->seqnum_h,
-					  oh_seqnum_l, oh_seqnum_h);
+				zlog_err(
+					"RECV[%s] : Nbr(%s) Auth Sequence number mismatch in %s ",
+					oi->interface->name, on->name,
+					ospf6_message_type(oh->type));
+				zlog_err(
+					"nbr_seq_l %u, nbr_seq_h %u, hdr_seq_l %u, hdr_seq_h %u",
+					on->seqnum_l[oh->type],
+					on->seqnum_h[oh->type], oh_seqnum_l,
+					oh_seqnum_h);
 			}
 
-			oi->at_data.rx_drop++;
-			return -1;
+			return OSPF6_AUTH_VALIDATE_FAILURE;
 		}
 	}
 
-	return 0;
+	return OSPF6_AUTH_VALIDATE_SUCCESS;
 }
 
 /* Starting point of packet process function. */
 int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
-			    struct in6_addr *src)
+			    struct in6_addr *src, unsigned int lls_block_len)
 {
 	uint32_t hash_len = KEYCHAIN_MAX_HASH_SIZE;
 	unsigned char apad[hash_len];
@@ -459,32 +476,31 @@ int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
 	uint16_t auth_len = 0;
 	uint8_t hash_algo = 0;
 	uint16_t oh_len = ntohs(oh->length);
+	int ret = 0;
 
 	if (oi->at_data.flags == 0)
-		return -2;
+		return OSPF6_AUTH_PROCESS_NORMAL;
 
-	ospf6_auth = (struct ospf6_auth_hdr *)((uint8_t *)oh + oh_len);
+	ospf6_auth = (struct ospf6_auth_hdr *)((uint8_t *)oh + oh_len
+					       + lls_block_len);
 	if (CHECK_FLAG(oi->at_data.flags, OSPF6_AUTH_TRAILER_KEYCHAIN)) {
 		keychain = keychain_lookup(oi->at_data.keychain);
 		if (!keychain) {
 			if (IS_OSPF6_DEBUG_AUTH_RX)
-				zlog_warn("RECV[%s]: Keychain does't exist for %s",
-					  oi->interface->name,
-					  lookup_msg(ospf6_message_type_str,
-						     oh->type, NULL));
-			oi->at_data.rx_drop++;
-			return -1;
+				zlog_err(
+					"RECV[%s]: Keychain does't exist for %s",
+					oi->interface->name,
+					ospf6_message_type(oh->type));
+			return OSPF6_AUTH_VALIDATE_FAILURE;
 		}
 
 		key = key_lookup_for_accept(keychain, ntohs(ospf6_auth->id));
 		if (!key) {
 			if (IS_OSPF6_DEBUG_AUTH_RX)
-				zlog_warn("RECV[%s]: Auth, Invalid SA for %s",
-					  oi->interface->name,
-					  lookup_msg(ospf6_message_type_str,
-						     oh->type, NULL));
-			oi->at_data.rx_drop++;
-			return -1;
+				zlog_err("RECV[%s]: Auth, Invalid SA for %s",
+					 oi->interface->name,
+					 ospf6_message_type(oh->type));
+			return OSPF6_AUTH_VALIDATE_FAILURE;
 		}
 
 		if (key && key->string
@@ -493,12 +509,11 @@ int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
 			hash_algo = key->hash_algo;
 		} else {
 			if (IS_OSPF6_DEBUG_AUTH_RX)
-				zlog_warn("RECV[%s]: Incomplete keychain config for %s",
-					  oi->interface->name,
-					  lookup_msg(ospf6_message_type_str,
-						     oh->type, NULL));
-			oi->at_data.rx_drop++;
-			return -1;
+				zlog_err(
+					"RECV[%s]: Incomplete keychain config for %s",
+					oi->interface->name,
+					ospf6_message_type(oh->type));
+			return OSPF6_AUTH_VALIDATE_FAILURE;
 		}
 	} else if (CHECK_FLAG(oi->at_data.flags,
 			      OSPF6_AUTH_TRAILER_MANUAL_KEY)) {
@@ -507,11 +522,11 @@ int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
 	}
 
 	if (!auth_str)
-		return -2;
+		return OSPF6_AUTH_VALIDATE_FAILURE;
 
 	hash_len = keychain_get_hash_len(hash_algo);
-	memset(apad, 0, sizeof(hash_len));
-	memset(temp_hash, 0, sizeof(hash_len));
+	memset(apad, 0, sizeof(apad));
+	memset(temp_hash, 0, sizeof(temp_hash));
 
 	/* start digest verification */
 	memcpy(apad, src, ipv6_addr_size);
@@ -523,14 +538,19 @@ int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
 	memcpy(temp_hash, ospf6_auth->data, hash_len);
 	memcpy(ospf6_auth->data, apad, hash_len);
 
-	ospf6_auth_update_digest(oi, oh, ospf6_auth, auth_str, auth_len,
-				 (oh_len + auth_len), hash_algo);
+	ospf6_auth_update_digest(oi, oh, ospf6_auth, auth_str,
+				 (oh_len + auth_len + lls_block_len),
+				 hash_algo);
 
 #ifdef CRYPTO_OPENSSL
-	return !(CRYPTO_memcmp(temp_hash, ospf6_auth->data, hash_len));
+	ret = CRYPTO_memcmp(temp_hash, ospf6_auth->data, hash_len);
 #else
-	return !(memcmp(temp_hash, ospf6_auth->data, hash_len));
+	ret = memcmp(temp_hash, ospf6_auth->data, hash_len);
 #endif
+	if (ret == 0)
+		return OSPF6_AUTH_VALIDATE_SUCCESS;
+
+	return OSPF6_AUTH_VALIDATE_FAILURE;
 }
 
 void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
@@ -547,6 +567,7 @@ void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 	uint32_t hash_len = KEYCHAIN_MAX_HASH_SIZE;
 	unsigned char apad[hash_len];
 	int ipv6_addr_size = sizeof(struct in6_addr);
+	struct ospf6 *ospf6 = NULL;
 
 	if (CHECK_FLAG(oi->at_data.flags, OSPF6_AUTH_TRAILER_KEYCHAIN)) {
 		if (CHECK_FLAG(oi->at_data.flags,
@@ -576,8 +597,7 @@ void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 		if (IS_OSPF6_DEBUG_AUTH_TX)
 			zlog_warn("SEND[%s]: Authentication not configured for %s",
 				  oi->interface->name,
-				  lookup_msg(ospf6_message_type_str,
-					     oh->type, NULL));
+				  ospf6_message_type(oh->type));
 		return;
 	}
 
@@ -585,27 +605,33 @@ void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 		if (IS_OSPF6_DEBUG_AUTH_TX)
 			zlog_warn("SEND[%s]: Authentication key is not configured for %s",
 				  oi->interface->name,
-				  lookup_msg(ospf6_message_type_str,
-					     oh->type, NULL));
+				  ospf6_message_type(oh->type));
 		return;
 	}
 
 	hash_len = keychain_get_hash_len(hash_algo);
-	oi->at_data.seqnum_l++;
+	if (oi->area && oi->area->ospf6)
+		ospf6 = oi->area->ospf6;
+	else
+		return;
 
-	if (oi->at_data.seqnum_l == 0xFFFFFFFF) {
-		oi->at_data.seqnum_h++;
-		oi->at_data.seqnum_l = 0;
+	ospf6->seqnum_l++;
+	if (ospf6->seqnum_l == 0xFFFFFFFF) {
+		ospf6->seqnum_h++;
+		ospf6->seqnum_l = 0;
+		ospf6_auth_seqno_nvm_update(ospf6);
 	}
 
 	/* Key must be reset. which is not handled as of now. */
-	if ((oi->at_data.seqnum_l == 0xFFFFFFFF)
-	    && (oi->at_data.seqnum_h == 0xFFFFFFFF)) {
-		oi->at_data.seqnum_l = 0;
-		oi->at_data.seqnum_h = 0;
+	if ((ospf6->seqnum_l == 0xFFFFFFFF)
+	    && (ospf6->seqnum_h == 0xFFFFFFFF)) {
+		ospf6->seqnum_l = 0;
+		ospf6->seqnum_h = 0;
+		zlog_err(
+			"Both Higher and Lower sequence number has wrapped. Need to reset the key");
 	}
 
-	memset(apad, 0, hash_len);
+	memset(apad, 0, sizeof(apad));
 
 	if (src)
 		memcpy(apad, src, ipv6_addr_size);
@@ -619,13 +645,18 @@ void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 	ospf6_auth->length = htons(auth_len);
 	ospf6_auth->reserved = 0;
 	ospf6_auth->id = htons(key_id);
-	ospf6_auth->seqnum_h = htonl(oi->at_data.seqnum_h);
-	ospf6_auth->seqnum_l = htonl(oi->at_data.seqnum_l);
+	ospf6_auth->seqnum_h = htonl(ospf6->seqnum_h);
+	ospf6_auth->seqnum_l = htonl(ospf6->seqnum_l);
 	memcpy(ospf6_auth->data, apad, hash_len);
 
-	ospf6_auth_update_digest(oi, oh, ospf6_auth, auth_str, auth_len,
-				 pkt_len, hash_algo);
+	ospf6_auth_update_digest(oi, oh, ospf6_auth, auth_str, pkt_len,
+				 hash_algo);
 
+	/* There is a optimisation that is done to ensure that
+	 * for every packet flow keychain lib API are called
+	 * only once and the result are stored in oi->at_data.
+	 * So, After processing the flow it is reset back here.
+	 */
 	if (CHECK_FLAG(oi->at_data.flags, OSPF6_AUTH_TRAILER_KEYCHAIN_VALID)) {
 		oi->at_data.hash_algo = KEYCHAIN_ALGO_NULL;
 		if (oi->at_data.auth_key) {
@@ -643,24 +674,26 @@ void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 void ospf6_auth_update_digest(struct ospf6_interface *oi,
 			      struct ospf6_header *oh,
 			      struct ospf6_auth_hdr *ospf6_auth, char *auth_str,
-			      uint16_t auth_len, uint32_t pkt_len,
-			      enum keychain_hash_algo algo)
+			      uint32_t pkt_len, enum keychain_hash_algo algo)
 {
+	static const uint16_t cpid = 1;
 	uint32_t hash_len = keychain_get_hash_len(algo);
 	uint32_t block_s = keychain_get_block_size(algo);
 	uint32_t k_len = strlen(auth_str);
-	uint32_t ks_len = strlen(auth_str) + sizeof(CPID);
+	uint32_t ks_len = strlen(auth_str) + sizeof(cpid);
 	unsigned char ipad[block_s];
 	unsigned char opad[block_s];
 	unsigned char ko[block_s], ks[ks_len], tmp[hash_len];
 	unsigned char *first = NULL;
 	unsigned char *second = NULL;
-	unsigned char *first_mes, *second_mes;
-	unsigned char *first_hash, *second_hash;
+	unsigned char first_mes[block_s + pkt_len];
+	unsigned char second_mes[block_s + pkt_len];
+	unsigned char first_hash[hash_len];
+	unsigned char second_hash[hash_len];
 
-	memset(ko, 0, block_s);
+	memset(ko, 0, sizeof(ko));
 	memcpy(ks, auth_str, k_len);
-	memcpy(ks + k_len, &CPID, sizeof(CPID));
+	memcpy(ks + k_len, &cpid, sizeof(cpid));
 	if (ks_len > hash_len) {
 		ospf6_hash_hmac_sha_digest(algo, ks, ks_len, tmp);
 		memcpy(ko, tmp, hash_len);
@@ -673,31 +706,19 @@ void ospf6_auth_update_digest(struct ospf6_interface *oi,
 	first = ospf6_hash_message_xor((unsigned char *)&ipad, ko, block_s);
 	second = ospf6_hash_message_xor((unsigned char *)&opad, ko, block_s);
 
-	first_mes = XMALLOC(MTYPE_OSPF6_AUTH_PKT, (block_s + pkt_len));
-
 	memcpy(first_mes, first, block_s);
 	memcpy(first_mes + block_s, oh, pkt_len);
 
-	first_hash = XMALLOC(MTYPE_OSPF6_AUTH_HASH, hash_len);
-
 	ospf6_hash_hmac_sha_digest(algo, first_mes, (block_s + pkt_len),
 				   first_hash);
 
-	second_mes = XMALLOC(MTYPE_OSPF6_AUTH_PKT, (block_s + hash_len));
-
 	memcpy(second_mes, second, block_s);
 	memcpy(second_mes + block_s, first_hash, hash_len);
 
-	second_hash = XMALLOC(MTYPE_OSPF6_AUTH_HASH, hash_len);
-
 	ospf6_hash_hmac_sha_digest(algo, second_mes, (block_s + hash_len),
 				   second_hash);
 
 	memcpy(ospf6_auth->data, second_hash, hash_len);
-	XFREE(MTYPE_OSPF6_AUTH_PKT, first_mes);
-	XFREE(MTYPE_OSPF6_AUTH_PKT, second_mes);
-	XFREE(MTYPE_OSPF6_AUTH_HASH, first_hash);
-	XFREE(MTYPE_OSPF6_AUTH_HASH, second_hash);
 	XFREE(MTYPE_OSPF6_AUTH_HASH_XOR, first);
 	XFREE(MTYPE_OSPF6_AUTH_HASH_XOR, second);
 }
@@ -792,31 +813,50 @@ static void ospf6_intf_auth_clear(struct vty *vty, struct interface *ifp)
 }
 
 /* Clear interface */
-DEFUN(clear_ipv6_ospf6_intf_auth,
-      clear_ipv6_ospf6_intf_auth_cmd,
-      "clear ipv6 ospf6 auth-counters interface [IFNAME]",
-      CLEAR_STR
-      IP6_STR
-      OSPF6_STR
-      "authentication rx/tx drop counters\n"
-      INTERFACE_STR
-      IFNAME_STR)
+DEFUN(clear_ipv6_ospf6_intf_auth, clear_ipv6_ospf6_intf_auth_cmd,
+      "clear ipv6 ospf6 [vrf VRF] auth-counters interface [IFNAME]",
+      CLEAR_STR IP6_STR OSPF6_STR VRF_CMD_HELP_STR
+      "authentication rx/tx drop counters\n" INTERFACE_STR IFNAME_STR)
 {
-	struct vrf *vrf = vrf_lookup_by_id(VRF_DEFAULT);
-	int idx_ifname = 5;
+	int idx_ifname = 0;
+	int idx_vrf = 0;
 	struct interface *ifp;
+	struct listnode *node;
+	struct ospf6 *ospf6 = NULL;
+	char *vrf_name = NULL;
+	vrf_id_t vrf_id = VRF_DEFAULT;
+	struct vrf *vrf = NULL;
+
+	if (argv_find(argv, argc, "vrf", &idx_vrf))
+		vrf_name = argv[idx_vrf + 1]->arg;
+
+	if (vrf_name && strmatch(vrf_name, VRF_DEFAULT_NAME))
+		vrf_name = NULL;
+
+	if (vrf_name) {
+		vrf = vrf_lookup_by_name(vrf_name);
+		if (vrf)
+			vrf_id = vrf->vrf_id;
+	}
 
-	if (argc == 5) { /* Clear all the ospfv3 interfaces. */
-		FOR_ALL_INTERFACES (vrf, ifp)
-			ospf6_intf_auth_clear(vty, ifp);
-	} else { /* Interface name is specified. */
-		ifp = if_lookup_by_name(argv[idx_ifname]->arg, VRF_DEFAULT);
-		if (ifp  == NULL) {
-			vty_out(vty, "Error: No such Interface: %s\n",
-				argv[idx_ifname]->arg);
-			return CMD_WARNING;
+	if (!argv_find(argv, argc, "IFNAME", &idx_ifname)) {
+		/* Clear all the ospfv3 interfaces auth data. */
+		for (ALL_LIST_ELEMENTS_RO(om6->ospf6, node, ospf6)) {
+			if (vrf_id != ospf6->vrf_id)
+				continue;
+
+			if (!vrf)
+				vrf = vrf_lookup_by_id(ospf6->vrf_id);
+			FOR_ALL_INTERFACES (vrf, ifp)
+				ospf6_intf_auth_clear(vty, ifp);
 		}
-		ospf6_intf_auth_clear(vty, ifp);
+	} else {
+		/* Interface name is specified. */
+		ifp = if_lookup_by_name(argv[idx_ifname]->arg, vrf_id);
+		if (ifp == NULL)
+			vty_out(vty, "No such interface name\n");
+		else
+			ospf6_intf_auth_clear(vty, ifp);
 	}
 
 	return CMD_SUCCESS;
@@ -826,3 +866,135 @@ void install_element_ospf6_clear_intf_auth(void)
 {
 	install_element(ENABLE_NODE, &clear_ipv6_ospf6_intf_auth_cmd);
 }
+
+enum ospf6_auth_err ospf6_auth_nvm_file_exist(void)
+{
+	struct stat buffer;
+	int exist;
+
+	exist = stat(OSPF6_AUTH_SEQ_NUM_FILE, &buffer);
+	if (exist == 0)
+		return OSPF6_AUTH_FILE_EXIST;
+	else
+		return OSPF6_AUTH_FILE_DO_NOT_EXIST;
+}
+
+/*
+ * Record in non-volatile memory the given ospf6 process,
+ * authentication trailer higher order sequence number.
+ */
+void ospf6_auth_seqno_nvm_update(struct ospf6 *ospf6)
+{
+	const char *inst_name;
+	json_object *json;
+	json_object *json_instances;
+	json_object *json_instance;
+
+	zlog_err("Higher order sequence number %d update for %s process",
+		 ospf6->seqnum_h, ospf6->name);
+
+	inst_name = ospf6->name ? ospf6->name : VRF_DEFAULT_NAME;
+
+	json = json_object_from_file((char *)OSPF6_AUTH_SEQ_NUM_FILE);
+	if (json == NULL)
+		json = json_object_new_object();
+
+	json_object_object_get_ex(json, "instances", &json_instances);
+	if (!json_instances) {
+		json_instances = json_object_new_object();
+		json_object_object_add(json, "instances", json_instances);
+	}
+
+	json_object_object_get_ex(json_instances, inst_name, &json_instance);
+	if (!json_instance) {
+		json_instance = json_object_new_object();
+		json_object_object_add(json_instances, inst_name,
+				       json_instance);
+	}
+
+	/*
+	 * Record higher order sequence number in non volatile memory.
+	 */
+	json_object_int_add(json_instance, "sequence_number", ospf6->seqnum_h);
+
+	json_object_to_file_ext((char *)OSPF6_AUTH_SEQ_NUM_FILE, json,
+				JSON_C_TO_STRING_PRETTY);
+	json_object_free(json);
+}
+
+/*
+ * Delete authentication sequence number for a given OSPF6 process
+ * from non-volatile memory.
+ */
+void ospf6_auth_seqno_nvm_delete(struct ospf6 *ospf6)
+{
+	const char *inst_name;
+	json_object *json;
+	json_object *json_instances;
+
+	zlog_err("Higher order sequence number delete for %s process",
+		 ospf6->name);
+
+	inst_name = ospf6->name ? ospf6->name : VRF_DEFAULT_NAME;
+
+	json = json_object_from_file((char *)OSPF6_AUTH_SEQ_NUM_FILE);
+	if (json == NULL)
+		json = json_object_new_object();
+
+	json_object_object_get_ex(json, "instances", &json_instances);
+	if (!json_instances) {
+		json_instances = json_object_new_object();
+		json_object_object_add(json, "instances", json_instances);
+	}
+
+	json_object_object_del(json_instances, inst_name);
+
+	json_object_to_file_ext((char *)OSPF6_AUTH_SEQ_NUM_FILE, json,
+				JSON_C_TO_STRING_PRETTY);
+	json_object_free(json);
+}
+
+
+/*
+ * Fetch from non-volatile memory the stored ospf6 process
+ * authentication sequence number.
+ */
+void ospf6_auth_seqno_nvm_read(struct ospf6 *ospf6)
+{
+	const char *inst_name;
+	json_object *json;
+	json_object *json_instances;
+	json_object *json_instance;
+	json_object *json_seqnum;
+
+	inst_name = ospf6->name ? ospf6->name : VRF_DEFAULT_NAME;
+
+	json = json_object_from_file((char *)OSPF6_AUTH_SEQ_NUM_FILE);
+	if (json == NULL)
+		json = json_object_new_object();
+
+	json_object_object_get_ex(json, "instances", &json_instances);
+	if (!json_instances) {
+		json_instances = json_object_new_object();
+		json_object_object_add(json, "instances", json_instances);
+	}
+
+	json_object_object_get_ex(json_instances, inst_name, &json_instance);
+	if (!json_instance) {
+		json_instance = json_object_new_object();
+		json_object_object_add(json_instances, inst_name,
+				       json_instance);
+	}
+
+	json_object_object_get_ex(json_instance, "sequence_number",
+				  &json_seqnum);
+	ospf6->seqnum_h = json_object_get_int(json_seqnum);
+
+	zlog_err("Higher order sequence number %d read for %s process %s",
+		 ospf6->seqnum_h, ospf6->name, strerror(errno));
+
+	json_object_object_del(json_instances, inst_name);
+	json_object_to_file_ext((char *)OSPF6_AUTH_SEQ_NUM_FILE, json,
+				JSON_C_TO_STRING_PRETTY);
+	json_object_free(json);
+}
diff --git a/ospf6d/ospf6_auth_trailer.h b/ospf6d/ospf6_auth_trailer.h
index fa2de28ef..86ec49beb 100644
--- a/ospf6d/ospf6_auth_trailer.h
+++ b/ospf6d/ospf6_auth_trailer.h
@@ -27,12 +27,12 @@
 #define OSPF6_AUTH_HDR_MIN_SIZE 16
 #define OSPF6_AUTH_HDR_FULL     KEYCHAIN_MAX_HASH_SIZE + OSPF6_AUTH_HDR_MIN_SIZE
 
-#define OSPF6_AUTHENTICATION_NULL                 0
-#define OSPF6_AUTHENTICATION_CRYPTOGRAPHIC        1
-static const uint16_t CPID = 1;
+#define OSPF6_AUTHENTICATION_NULL 0
+#define OSPF6_AUTHENTICATION_CRYPTOGRAPHIC 1
 
 /* Auth debug options */
 extern unsigned char conf_debug_ospf6_auth[2];
+
 #define OSPF6_AUTH_TX 0
 #define OSPF6_AUTH_RX 1
 #define OSPF6_DEBUG_AUTH_TX_ON() (conf_debug_ospf6_auth[OSPF6_AUTH_TX] = 1)
@@ -57,24 +57,37 @@ struct ospf6_auth_hdr {
 	unsigned char data[KEYCHAIN_MAX_HASH_SIZE];
 };
 
+enum ospf6_auth_err {
+	OSPF6_AUTH_VALIDATE_SUCCESS = 0,
+	OSPF6_AUTH_VALIDATE_FAILURE,
+	OSPF6_AUTH_PROCESS_NORMAL,
+	OSPF6_AUTH_FILE_EXIST,
+	OSPF6_AUTH_FILE_DO_NOT_EXIST
+};
+
 void ospf6_auth_hdr_dump_send(struct ospf6_header *ospfh, uint16_t length);
-void ospf6_auth_hdr_dump_recv(struct ospf6_header *ospfh, uint16_t length);
+void ospf6_auth_hdr_dump_recv(struct ospf6_header *ospfh, uint16_t length,
+			      unsigned int lls_len);
 unsigned char *ospf6_hash_message_xor(unsigned char *mes1, unsigned char *mes2,
 				      uint32_t len);
 unsigned int ospf6_auth_len_get(struct ospf6_interface *oi);
 int ospf6_auth_validate_pkt(struct ospf6_interface *oi, unsigned int *pkt_len,
-			    struct ospf6_header *oh, unsigned int *at_len);
+			    struct ospf6_header *oh, unsigned int *at_len,
+			    unsigned int *lls_block_len);
 int ospf6_auth_check_digest(struct ospf6_header *oh, struct ospf6_interface *oi,
-			    struct in6_addr *src);
+			    struct in6_addr *src, unsigned int lls_len);
 void ospf6_auth_update_digest(struct ospf6_interface *oi,
 			      struct ospf6_header *oh,
 			      struct ospf6_auth_hdr *ospf6_auth, char *auth_str,
-			      uint16_t auth_len, uint32_t pkt_len,
-			      enum keychain_hash_algo algo);
+			      uint32_t pkt_len, enum keychain_hash_algo algo);
 void ospf6_auth_digest_send(struct in6_addr *src, struct ospf6_interface *oi,
 			    struct ospf6_header *oh, uint16_t auth_len,
 			    uint32_t pkt_len);
 void install_element_ospf6_debug_auth(void);
 int config_write_ospf6_debug_auth(struct vty *vty);
 void install_element_ospf6_clear_intf_auth(void);
+enum ospf6_auth_err ospf6_auth_nvm_file_exist(void);
+void ospf6_auth_seqno_nvm_update(struct ospf6 *ospf6);
+void ospf6_auth_seqno_nvm_delete(struct ospf6 *ospf6);
+void ospf6_auth_seqno_nvm_read(struct ospf6 *ospf6);
 #endif /* __OSPF6_AUTH_TRAILER_H__ */
diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index 761a86444..f39d208bb 100644
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -1260,10 +1260,6 @@ static int ospf6_interface_show(struct vty *vty, struct interface *ifp,
 					      OSPF6_AUTH_TRAILER_MANUAL_KEY))
 				json_object_string_add(json_auth, "authType",
 						       "manualkey");
-			json_object_int_add(json_auth, "higherSegNo",
-					    oi->at_data.seqnum_h);
-			json_object_int_add(json_auth, "lowerSegNo",
-					    oi->at_data.seqnum_l);
 			json_object_int_add(json_auth, "txPktDrop",
 					    oi->at_data.tx_drop);
 			json_object_int_add(json_auth, "rxPktDrop",
@@ -1278,20 +1274,15 @@ static int ospf6_interface_show(struct vty *vty, struct interface *ifp,
 					    OSPF6_AUTH_TRAILER_MANUAL_KEY))
 				vty_out(vty,
 					"  Authentication trailer is enabled with manual key\n");
-
-			vty_out(vty,
-				"    Higher sequence no %u, Lower sequence no %u\n",
-				oi->at_data.seqnum_h, oi->at_data.seqnum_l);
 			vty_out(vty,
 				"    Packet drop Tx %u, Packet drop Rx %u\n",
 				oi->at_data.tx_drop, oi->at_data.rx_drop);
 		}
 	} else {
-		if (use_json) {
+		if (use_json)
 			json_object_string_add(json_auth, "authType", "NULL");
-		} else {
+		else
 			vty_out(vty, "  Authentication Trailer is disabled\n");
-		}
 	}
 
 	if (use_json)
diff --git a/ospf6d/ospf6_interface.h b/ospf6d/ospf6_interface.h
index d6a2b52e1..59e4888a5 100644
--- a/ospf6d/ospf6_interface.h
+++ b/ospf6d/ospf6_interface.h
@@ -35,32 +35,18 @@ extern unsigned char conf_debug_ospf6_interface;
 #define IS_OSPF6_DEBUG_INTERFACE (conf_debug_ospf6_interface)
 
 struct ospf6_auth_data {
-	/* higher order Sequence Number */
-	uint32_t seqnum_h;
-
-	/* lower order Sequence Number */
-	uint32_t seqnum_l;
-
-	/* Packet drop due to auth failure while sending */
-	uint32_t tx_drop;
-
-	/* Packet drop due to auth failure while reading */
-	uint32_t rx_drop;
-
-	/* hash algorithm type */
-	uint8_t hash_algo;
-
-	/* Flags related to auth config */
-	uint8_t flags;
-
-	/* key-id used as security association in auth packet */
-	uint16_t key_id;
-
-	/* Auth key */
-	char *auth_key;
-
-	/* keychain name */
-	char *keychain;
+	/* config data */
+	uint8_t hash_algo; /* hash algorithm type */
+	uint16_t key_id;   /* key-id used as SA in auth packet */
+	char *auth_key;    /* Auth key */
+	char *keychain;    /* keychain name */
+
+	/* operational data */
+	uint8_t flags; /* Flags related to auth config */
+
+	/* Counters and Statistics */
+	uint32_t tx_drop; /* Pkt drop due to auth fail while sending */
+	uint32_t rx_drop; /* Pkt drop due to auth fail while reading */
 };
 
 /* Interface structure */
diff --git a/ospf6d/ospf6_intra.c b/ospf6d/ospf6_intra.c
index 6626b4bed..da5cad053 100644
--- a/ospf6d/ospf6_intra.c
+++ b/ospf6d/ospf6_intra.c
@@ -2148,7 +2148,7 @@ static void ospf6_brouter_debug_print(struct ospf6_route *brouter)
 	char installed[64], changed[64];
 	struct timeval now, res;
 	char id[16], adv_router[16];
-	char capa[16], options[16];
+	char capa[16], options[32];
 
 	brouter_id = ADV_ROUTER_IN_PREFIX(&brouter->prefix);
 	inet_ntop(AF_INET, &brouter_id, brouter_name, sizeof(brouter_name));
diff --git a/ospf6d/ospf6_message.c b/ospf6d/ospf6_message.c
index 352cb137e..c1004a708 100644
--- a/ospf6d/ospf6_message.c
+++ b/ospf6d/ospf6_message.c
@@ -27,6 +27,7 @@
 #include "thread.h"
 #include "linklist.h"
 #include "lib_errors.h"
+#include "checksum.h"
 
 #include "ospf6_proto.h"
 #include "ospf6_lsa.h"
@@ -48,19 +49,34 @@
 #include "ospf6d.h"
 #include "ospf6_gr.h"
 #include <netinet/ip6.h>
+#include "lib/libospf.h"
+#include "lib/keychain.h"
+#include "ospf6_auth_trailer.h"
 
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_MESSAGE, "OSPF6 message");
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_PACKET, "OSPF6 packet");
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_FIFO, "OSPF6  FIFO queue");
 
 unsigned char conf_debug_ospf6_message[6] = {0x03, 0, 0, 0, 0, 0};
-static const struct message ospf6_message_type_str[] = {
-	{OSPF6_MESSAGE_TYPE_HELLO, "Hello"},
-	{OSPF6_MESSAGE_TYPE_DBDESC, "DbDesc"},
-	{OSPF6_MESSAGE_TYPE_LSREQ, "LSReq"},
-	{OSPF6_MESSAGE_TYPE_LSUPDATE, "LSUpdate"},
-	{OSPF6_MESSAGE_TYPE_LSACK, "LSAck"},
-	{0}};
+
+const char *ospf6_message_type(int type)
+{
+	switch (type) {
+	case OSPF6_MESSAGE_TYPE_HELLO:
+		return "Hello";
+	case OSPF6_MESSAGE_TYPE_DBDESC:
+		return "DbDesc";
+	case OSPF6_MESSAGE_TYPE_LSREQ:
+		return "LSReq";
+	case OSPF6_MESSAGE_TYPE_LSUPDATE:
+		return "LSUpdate";
+	case OSPF6_MESSAGE_TYPE_LSACK:
+		return "LSAck";
+	case OSPF6_MESSAGE_TYPE_UNKNOWN:
+	default:
+		return "unknown";
+	}
+}
 
 /* Minimum (besides the standard OSPF packet header) lengths for OSPF
    packets of particular types, offset is the "type" field. */
@@ -101,7 +117,7 @@ static void ospf6_header_print(struct ospf6_header *oh)
 void ospf6_hello_print(struct ospf6_header *oh, int action)
 {
 	struct ospf6_hello *hello;
-	char options[16];
+	char options[32];
 	char *p;
 
 	ospf6_header_print(oh);
@@ -136,7 +152,7 @@ void ospf6_hello_print(struct ospf6_header *oh, int action)
 void ospf6_dbdesc_print(struct ospf6_header *oh, int action)
 {
 	struct ospf6_dbdesc *dbdesc;
-	char options[16];
+	char options[32];
 	char *p;
 
 	ospf6_header_print(oh);
@@ -439,6 +455,20 @@ static void ospf6_hello_recv(struct in6_addr *src, struct in6_addr *dst,
 		return;
 	}
 
+	if (((OSPF6_OPT_ISSET_EXT(hello->options, OSPF6_OPT_AT) ==
+	      OSPF6_OPT_AT) &&
+	     (oi->at_data.flags == 0)) ||
+	    ((OSPF6_OPT_ISSET_EXT(hello->options, OSPF6_OPT_AT) !=
+	      OSPF6_OPT_AT) &&
+	     (oi->at_data.flags != 0))) {
+		if (IS_OSPF6_DEBUG_AUTH_RX)
+			zlog_warn(
+				"VRF %s: IF %s AT-bit mismatch in hello packet",
+				oi->interface->vrf->name, oi->interface->name);
+		oi->at_data.rx_drop++;
+		return;
+	}
+
 	/* Find neighbor, create if not exist */
 	on = ospf6_neighbor_lookup(oh->router_id, oi);
 	if (on == NULL) {
@@ -1006,6 +1036,20 @@ static void ospf6_dbdesc_recv(struct in6_addr *src, struct in6_addr *dst,
 	dbdesc = (struct ospf6_dbdesc *)((caddr_t)oh
 					 + sizeof(struct ospf6_header));
 
+	if (((OSPF6_OPT_ISSET_EXT(dbdesc->options, OSPF6_OPT_AT) ==
+	      OSPF6_OPT_AT) &&
+	     (oi->at_data.flags == 0)) ||
+	    ((OSPF6_OPT_ISSET_EXT(dbdesc->options, OSPF6_OPT_AT) !=
+	      OSPF6_OPT_AT) &&
+	     (oi->at_data.flags != 0))) {
+		if (IS_OSPF6_DEBUG_AUTH_RX)
+			zlog_warn(
+				"VRF %s: IF %s AT-bit mismatch in dbdesc packet",
+				oi->interface->vrf->name, oi->interface->name);
+		oi->at_data.rx_drop++;
+		return;
+	}
+
 	/* Interface MTU check */
 	if (!oi->mtu_ignore && ntohs(dbdesc->ifmtu) != oi->ifmtu) {
 		zlog_warn("VRF %s: I/F %s MTU mismatch (my %d rcvd %d)",
@@ -1412,14 +1456,15 @@ static unsigned ospf6_packet_examin(struct ospf6_header *oh,
 			  bytesonwire);
 		return MSG_NG;
 	}
+
 	/* Now it is safe to access header fields. */
 	if (bytesonwire != ntohs(oh->length)) {
 		zlog_warn("%s: %s packet length error (%u real, %u declared)",
-			  __func__,
-			  lookup_msg(ospf6_message_type_str, oh->type, NULL),
-			  bytesonwire, ntohs(oh->length));
+			  __func__, ospf6_message_type(oh->type), bytesonwire,
+			  ntohs(oh->length));
 		return MSG_NG;
 	}
+
 	/* version check */
 	if (oh->version != OSPFV3_VERSION) {
 		zlog_warn("%s: invalid (%u) protocol version", __func__,
@@ -1431,8 +1476,7 @@ static unsigned ospf6_packet_examin(struct ospf6_header *oh,
 	    && bytesonwire
 		       < OSPF6_HEADER_SIZE + ospf6_packet_minlen[oh->type]) {
 		zlog_warn("%s: undersized (%u B) %s packet", __func__,
-			  bytesonwire,
-			  lookup_msg(ospf6_message_type_str, oh->type, NULL));
+			  bytesonwire, ospf6_message_type(oh->type));
 		return MSG_NG;
 	}
 	/* type-specific deeper validation */
@@ -1446,7 +1490,7 @@ static unsigned ospf6_packet_examin(struct ospf6_header *oh,
 			       % 4)
 			return MSG_OK;
 		zlog_warn("%s: alignment error in %s packet", __func__,
-			  lookup_msg(ospf6_message_type_str, oh->type, NULL));
+			  ospf6_message_type(oh->type));
 		return MSG_NG;
 	case OSPF6_MESSAGE_TYPE_DBDESC:
 		/* RFC5340 A.3.3, packet header + OSPF6_DB_DESC_MIN_SIZE bytes
@@ -1467,7 +1511,7 @@ static unsigned ospf6_packet_examin(struct ospf6_header *oh,
 			       % OSPF6_LSREQ_LSDESC_FIX_SIZE)
 			return MSG_OK;
 		zlog_warn("%s: alignment error in %s packet", __func__,
-			  lookup_msg(ospf6_message_type_str, oh->type, NULL));
+			  ospf6_message_type(oh->type));
 		return MSG_NG;
 	case OSPF6_MESSAGE_TYPE_LSUPDATE:
 		/* RFC5340 A.3.5, packet header + OSPF6_LS_UPD_MIN_SIZE bytes
@@ -1497,7 +1541,7 @@ static unsigned ospf6_packet_examin(struct ospf6_header *oh,
 	}
 	if (test != MSG_OK)
 		zlog_warn("%s: anomaly in %s packet", __func__,
-			  lookup_msg(ospf6_message_type_str, oh->type, NULL));
+			  ospf6_message_type(oh->type));
 	return test;
 }
 
@@ -1727,6 +1771,9 @@ static int ospf6_read_helper(int sockfd, struct ospf6 *ospf6)
 	struct iovec iovector[2];
 	struct ospf6_interface *oi;
 	struct ospf6_header *oh;
+	enum ospf6_auth_err ret = OSPF6_AUTH_PROCESS_NORMAL;
+	uint32_t at_len = 0;
+	uint32_t lls_len = 0;
 
 	/* initialize */
 	memset(&src, 0, sizeof(src));
@@ -1772,6 +1819,24 @@ static int ospf6_read_helper(int sockfd, struct ospf6 *ospf6)
 		return OSPF6_READ_CONTINUE;
 
 	oh = (struct ospf6_header *)recvbuf;
+	ret = ospf6_auth_validate_pkt(oi, (uint32_t *)&len, oh, &at_len,
+				      &lls_len);
+	if (ret == OSPF6_AUTH_VALIDATE_SUCCESS) {
+		ret = ospf6_auth_check_digest(oh, oi, &src, lls_len);
+		if (ret == OSPF6_AUTH_VALIDATE_FAILURE) {
+			if (IS_OSPF6_DEBUG_AUTH_RX)
+				zlog_err(
+					"RECV[%s]: OSPF packet auth digest miss-match on %s",
+					oi->interface->name,
+					ospf6_message_type(oh->type));
+			oi->at_data.rx_drop++;
+			return OSPF6_READ_CONTINUE;
+		}
+	} else if (ret == OSPF6_AUTH_VALIDATE_FAILURE) {
+		oi->at_data.rx_drop++;
+		return OSPF6_READ_CONTINUE;
+	}
+
 	if (ospf6_rxpacket_examin(oi, oh, len) != MSG_OK)
 		return OSPF6_READ_CONTINUE;
 
@@ -1782,8 +1847,7 @@ static int ospf6_read_helper(int sockfd, struct ospf6 *ospf6)
 
 	/* Log */
 	if (IS_OSPF6_DEBUG_MESSAGE(oh->type, RECV_HDR)) {
-		zlog_debug("%s received on %s",
-			   lookup_msg(ospf6_message_type_str, oh->type, NULL),
+		zlog_debug("%s received on %s", ospf6_message_type(oh->type),
 			   oi->interface->name);
 		zlog_debug("    src: %pI6", &src);
 		zlog_debug("    dst: %pI6", &dst);
@@ -1807,6 +1871,10 @@ static int ospf6_read_helper(int sockfd, struct ospf6 *ospf6)
 		default:
 			assert(0);
 		}
+
+		if ((at_len != 0) && IS_OSPF6_DEBUG_AUTH_RX)
+			ospf6_auth_hdr_dump_recv(oh, (len + at_len + lls_len),
+						 lls_len);
 	}
 
 	switch (oh->type) {
@@ -1863,6 +1931,27 @@ int ospf6_receive(struct thread *thread)
 	return 0;
 }
 
+static void ospf6_fill_hdr_checksum(struct ospf6_interface *oi,
+				    struct ospf6_packet *op)
+{
+	struct ipv6_ph ph = {};
+	struct ospf6_header *oh;
+	void *offset = NULL;
+
+	if (oi->at_data.flags != 0)
+		return;
+
+	memcpy(&ph.src, oi->linklocal_addr, sizeof(struct in6_addr));
+	memcpy(&ph.dst, &op->dst, sizeof(struct in6_addr));
+	ph.ulpl = htonl(op->length);
+	ph.next_hdr = IPPROTO_OSPFIGP;
+
+	/* Suppress static analysis warnings about accessing icmp6 oob */
+	oh = (struct ospf6_header *)STREAM_DATA(op->s);
+	offset = oh;
+	oh->checksum = in_cksum_with_ph6(&ph, offset, op->length);
+}
+
 static void ospf6_make_header(uint8_t type, struct ospf6_interface *oi,
 			      struct stream *s)
 {
@@ -1873,6 +1962,7 @@ static void ospf6_make_header(uint8_t type, struct ospf6_interface *oi,
 	oh->version = (uint8_t)OSPFV3_VERSION;
 	oh->type = type;
 	oh->length = 0;
+
 	oh->router_id = oi->area->ospf6->router_id;
 	oh->area_id = oi->area->area_id;
 	oh->checksum = 0;
@@ -1904,9 +1994,48 @@ static void ospf6_fill_lsupdate_header(struct stream *s, uint32_t lsa_num)
 	lsu->lsa_number = htonl(lsa_num);
 }
 
+static void ospf6_auth_trailer_copy_keychain_key(struct ospf6_interface *oi)
+{
+	char *keychain_name = NULL;
+	struct keychain *keychain = NULL;
+	struct key *key = NULL;
+
+	keychain_name = oi->at_data.keychain;
+	keychain = keychain_lookup(keychain_name);
+	if (keychain) {
+		key = key_lookup_for_send(keychain);
+		if (key && key->string &&
+		    key->hash_algo != KEYCHAIN_ALGO_NULL) {
+			/* storing the values so that further
+			 * lookup can be avoided. after
+			 * processing the digest need to reset
+			 * these values
+			 */
+			oi->at_data.hash_algo = key->hash_algo;
+			oi->at_data.auth_key = XSTRDUP(
+				MTYPE_OSPF6_AUTH_MANUAL_KEY, key->string);
+			oi->at_data.key_id = key->index;
+			SET_FLAG(oi->at_data.flags,
+				 OSPF6_AUTH_TRAILER_KEYCHAIN_VALID);
+		}
+	}
+}
+
 static uint32_t ospf6_packet_max(struct ospf6_interface *oi)
 {
+	int at_len = 0;
+
 	assert(oi->ifmtu > sizeof(struct ip6_hdr));
+
+	if (oi->at_data.flags != 0) {
+		if (CHECK_FLAG(oi->at_data.flags, OSPF6_AUTH_TRAILER_KEYCHAIN))
+			ospf6_auth_trailer_copy_keychain_key(oi);
+
+		at_len += OSPF6_AUTH_HDR_MIN_SIZE;
+		at_len += keychain_get_hash_len(oi->at_data.hash_algo);
+		return oi->ifmtu - (sizeof(struct ip6_hdr)) - at_len;
+	}
+
 	return oi->ifmtu - (sizeof(struct ip6_hdr));
 }
 
@@ -1915,11 +2044,15 @@ static uint16_t ospf6_make_hello(struct ospf6_interface *oi, struct stream *s)
 	struct listnode *node, *nnode;
 	struct ospf6_neighbor *on;
 	uint16_t length = OSPF6_HELLO_MIN_SIZE;
+	uint8_t options1 = oi->area->options[1];
+
+	if (oi->at_data.flags != 0)
+		options1 |= OSPF6_OPT_AT;
 
 	stream_putl(s, oi->interface->ifindex);
 	stream_putc(s, oi->priority);
 	stream_putc(s, oi->area->options[0]);
-	stream_putc(s, oi->area->options[1]);
+	stream_putc(s, options1);
 	stream_putc(s, oi->area->options[2]);
 	stream_putw(s, oi->hello_interval);
 	stream_putw(s, oi->dead_interval);
@@ -1959,6 +2092,7 @@ static int ospf6_write(struct thread *thread)
 	int len;
 	int64_t latency = 0;
 	struct timeval timestamp;
+	unsigned int at_len = 0;
 
 	if (ospf6->fd < 0) {
 		zlog_warn("ospf6_write failed to send, fd %d", ospf6->fd);
@@ -1983,17 +2117,32 @@ static int ospf6_write(struct thread *thread)
 
 		oh = (struct ospf6_header *)STREAM_DATA(op->s);
 
+		if (oi->at_data.flags != 0) {
+			at_len = ospf6_auth_len_get(oi);
+			if (at_len) {
+				iovector[0].iov_len =
+					ntohs(oh->length) + at_len;
+				ospf6_auth_digest_send(oi->linklocal_addr, oi,
+						       oh, at_len,
+						       iovector[0].iov_len);
+			} else {
+				iovector[0].iov_len = ntohs(oh->length);
+			}
+		} else {
+			iovector[0].iov_len = ntohs(oh->length);
+		}
+
 		len = ospf6_sendmsg(oi->linklocal_addr, &op->dst,
 				    oi->interface->ifindex, iovector,
 				    ospf6->fd);
-		if (len != op->length)
+
+		if (len != (op->length + (int)at_len))
 			flog_err(EC_LIB_DEVELOPMENT,
 				 "Could not send entire message");
 
 		if (IS_OSPF6_DEBUG_MESSAGE(oh->type, SEND_HDR)) {
 			zlog_debug("%s send on %s",
-				   lookup_msg(ospf6_message_type_str, oh->type,
-					      NULL),
+				   ospf6_message_type(oh->type),
 				   oi->interface->name);
 			zlog_debug("    src: %pI6", oi->linklocal_addr);
 			zlog_debug("    dst: %pI6", &op->dst);
@@ -2052,6 +2201,15 @@ static int ospf6_write(struct thread *thread)
 			assert(0);
 			break;
 		}
+
+		if ((oi->at_data.flags != 0) &&
+		    (IS_OSPF6_DEBUG_MESSAGE(oh->type, SEND_HDR)) &&
+		    (IS_OSPF6_DEBUG_AUTH_TX))
+			ospf6_auth_hdr_dump_send(oh, iovector[0].iov_len);
+
+		/* initialize at_len to 0 for next packet */
+		at_len = 0;
+
 		/* Now delete packet from queue. */
 		ospf6_packet_delete(oi);
 
@@ -2117,6 +2275,8 @@ int ospf6_hello_send(struct thread *thread)
 
 	op->dst = allspfrouters6;
 
+	ospf6_fill_hdr_checksum(oi, op);
+
 	/* Add packet to the top of the interface output queue, so that they
 	 * can't get delayed by things like long queues of LS Update packets
 	 */
@@ -2135,6 +2295,10 @@ static uint16_t ospf6_make_dbdesc(struct ospf6_neighbor *on, struct stream *s)
 {
 	uint16_t length = OSPF6_DB_DESC_MIN_SIZE;
 	struct ospf6_lsa *lsa, *lsanext;
+	uint8_t options1 = on->ospf6_if->area->options[1];
+
+	if (on->ospf6_if->at_data.flags != 0)
+		options1 |= OSPF6_OPT_AT;
 
 	/* if this is initial one, initialize sequence number for DbDesc */
 	if (CHECK_FLAG(on->dbdesc_bits, OSPF6_DBDESC_IBIT)
@@ -2145,7 +2309,7 @@ static uint16_t ospf6_make_dbdesc(struct ospf6_neighbor *on, struct stream *s)
 	/* reserved */
 	stream_putc(s, 0); /* reserved 1 */
 	stream_putc(s, on->ospf6_if->area->options[0]);
-	stream_putc(s, on->ospf6_if->area->options[1]);
+	stream_putc(s, options1);
 	stream_putc(s, on->ospf6_if->area->options[2]);
 	stream_putw(s, on->ospf6_if->ifmtu);
 	stream_putc(s, 0); /* reserved 2 */
@@ -2212,6 +2376,8 @@ int ospf6_dbdesc_send(struct thread *thread)
 	else
 		op->dst = on->linklocal_addr;
 
+	ospf6_fill_hdr_checksum(on->ospf6_if, op);
+
 	ospf6_packet_add(on->ospf6_if, op);
 
 	OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
@@ -2319,6 +2485,7 @@ static uint16_t ospf6_make_lsack_neighbor(struct ospf6_neighbor *on,
 
 				(*op)->length = length + OSPF6_HEADER_SIZE;
 				(*op)->dst = on->linklocal_addr;
+				ospf6_fill_hdr_checksum(on->ospf6_if, *op);
 				ospf6_packet_add(on->ospf6_if, *op);
 				OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
 				/* new packet */
@@ -2388,6 +2555,7 @@ int ospf6_lsreq_send(struct thread *thread)
 	else
 		op->dst = on->linklocal_addr;
 
+	ospf6_fill_hdr_checksum(on->ospf6_if, op);
 	ospf6_packet_add(on->ospf6_if, op);
 
 	OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
@@ -2425,6 +2593,7 @@ static void ospf6_send_lsupdate(struct ospf6_neighbor *on,
 			op->dst = alldrouters6;
 	}
 	if (oi) {
+		ospf6_fill_hdr_checksum(oi, op);
 		ospf6_packet_add(oi, op);
 		/* If ospf instance is being deleted, send the packet
 		 * immediately
@@ -2502,6 +2671,7 @@ static uint16_t ospf6_make_ls_retrans_list(struct ospf6_neighbor *on,
 			else
 				(*op)->dst = on->linklocal_addr;
 
+			ospf6_fill_hdr_checksum(on->ospf6_if, *op);
 			ospf6_packet_add(on->ospf6_if, *op);
 			OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
 
@@ -2573,6 +2743,7 @@ int ospf6_lsupdate_send_neighbor(struct thread *thread)
 			op->dst = allspfrouters6;
 		else
 			op->dst = on->linklocal_addr;
+		ospf6_fill_hdr_checksum(on->ospf6_if, op);
 		ospf6_packet_add(on->ospf6_if, op);
 		OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
 	} else
@@ -2739,6 +2910,7 @@ int ospf6_lsack_send_neighbor(struct thread *thread)
 	/* Set packet length, dst and queue to FIFO. */
 	op->length = length;
 	op->dst = on->linklocal_addr;
+	ospf6_fill_hdr_checksum(on->ospf6_if, op);
 	ospf6_packet_add(on->ospf6_if, op);
 	OSPF6_MESSAGE_WRITE_ON(on->ospf6_if);
 
@@ -2823,6 +2995,7 @@ int ospf6_lsack_send_interface(struct thread *thread)
 	else
 		op->dst = alldrouters6;
 
+	ospf6_fill_hdr_checksum(oi, op);
 	ospf6_packet_add(oi, op);
 	OSPF6_MESSAGE_WRITE_ON(oi);
 
diff --git a/ospf6d/ospf6_message.h b/ospf6d/ospf6_message.h
index 68cb4c779..437dd5685 100644
--- a/ospf6d/ospf6_message.h
+++ b/ospf6d/ospf6_message.h
@@ -23,10 +23,9 @@
 
 #define OSPF6_MESSAGE_BUFSIZ  4096
 
-extern const struct message ospf6_message_type_str[];
-
 /* Debug option */
 extern unsigned char conf_debug_ospf6_message[];
+
 #define OSPF6_ACTION_SEND 0x01
 #define OSPF6_ACTION_RECV 0x02
 #define OSPF6_DEBUG_MESSAGE_SEND 0x01
@@ -64,6 +63,7 @@ extern unsigned char conf_debug_ospf6_message[];
 #define OSPF6_MESSAGE_TYPE_LSUPDATE 0x4  /* Database update */
 #define OSPF6_MESSAGE_TYPE_LSACK    0x5  /* Flooding acknowledgment */
 #define OSPF6_MESSAGE_TYPE_ALL      0x6  /* For debug option */
+#define OSPF6_MESSAGE_TYPE_MAX 0x6       /* same as OSPF6_MESSAGE_TYPE_ALL */
 
 struct ospf6_packet {
 	struct ospf6_packet *next;
@@ -148,8 +148,16 @@ struct ospf6_lsupdate {
 	/* Followed by LSAs */
 };
 
+/* LLS is not supported, but used to derive
+ * offset of Auth_trailer
+ */
+struct ospf6_lls_hdr {
+	uint16_t checksum;
+	uint16_t length;
+};
+
 /* Link State Acknowledgement */
-#define OSPF6_LS_ACK_MIN_SIZE                  0U
+#define OSPF6_LS_ACK_MIN_SIZE 0U
 /* It is just a sequence of LSA Headers */
 
 /* Function definition */
@@ -178,5 +186,5 @@ extern int ospf6_lsack_send_neighbor(struct thread *thread);
 
 extern int config_write_ospf6_debug_message(struct vty *);
 extern void install_element_ospf6_debug_message(void);
-
+extern const char *ospf6_message_type(int type);
 #endif /* OSPF6_MESSAGE_H */
diff --git a/ospf6d/ospf6_neighbor.c b/ospf6d/ospf6_neighbor.c
index afa504d13..5d14bfc98 100644
--- a/ospf6d/ospf6_neighbor.c
+++ b/ospf6d/ospf6_neighbor.c
@@ -112,6 +112,7 @@ struct ospf6_neighbor *ospf6_neighbor_create(uint32_t router_id,
 {
 	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));
@@ -131,6 +132,13 @@ struct ospf6_neighbor *ospf6_neighbor_create(uint32_t router_id,
 	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);
@@ -935,8 +943,44 @@ static void ospf6_neighbor_show_detail(struct vty *vty,
 
 		bfd_sess_show(vty, json_neighbor, on->bfd_session);
 
-		json_object_object_add(json, on->name, json_neighbor);
+		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);
@@ -1022,6 +1066,27 @@ static void ospf6_neighbor_show_detail(struct vty *vty,
 			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");
 	}
 }
 
diff --git a/ospf6d/ospf6_neighbor.h b/ospf6d/ospf6_neighbor.h
index de59a1ccf..2dd640099 100644
--- a/ospf6d/ospf6_neighbor.h
+++ b/ospf6d/ospf6_neighbor.h
@@ -144,6 +144,14 @@ struct ospf6_neighbor {
 
 	/* ospf6 graceful restart HELPER info */
 	struct ospf6_helper_info gr_helper_info;
+
+	/* seqnum_h/l is used to compare sequence
+	 * number in received packet Auth header
+	 */
+	uint32_t seqnum_h[OSPF6_MESSAGE_TYPE_MAX];
+	uint32_t seqnum_l[OSPF6_MESSAGE_TYPE_MAX];
+	bool auth_present;
+	bool lls_present;
 };
 
 /* Neighbor state */
diff --git a/ospf6d/ospf6_network.c b/ospf6d/ospf6_network.c
index 5961cfe66..7501f49fe 100644
--- a/ospf6d/ospf6_network.c
+++ b/ospf6d/ospf6_network.c
@@ -33,6 +33,7 @@
 #include "ospf6_top.h"
 #include "ospf6_network.h"
 #include "ospf6d.h"
+#include "ospf6_message.h"
 
 struct in6_addr allspfrouters6;
 struct in6_addr alldrouters6;
@@ -60,20 +61,6 @@ static void ospf6_set_transport_class(int ospf6_sock)
 #endif
 }
 
-static void ospf6_set_checksum(int ospf6_sock)
-{
-	int offset = 12;
-#ifndef DISABLE_IPV6_CHECKSUM
-	if (setsockopt(ospf6_sock, IPPROTO_IPV6, IPV6_CHECKSUM, &offset,
-		       sizeof(offset))
-	    < 0)
-		zlog_warn("Network: set IPV6_CHECKSUM failed: %s",
-			  safe_strerror(errno));
-#else
-	zlog_warn("Network: Don't set IPV6_CHECKSUM");
-#endif /* DISABLE_IPV6_CHECKSUM */
-}
-
 void ospf6_serv_close(int *ospf6_sock)
 {
 	if (*ospf6_sock != -1) {
@@ -113,7 +100,6 @@ int ospf6_serv_sock(struct ospf6 *ospf6)
 	ospf6_reset_mcastloop(ospf6_sock);
 	ospf6_set_pktinfo(ospf6_sock);
 	ospf6_set_transport_class(ospf6_sock);
-	ospf6_set_checksum(ospf6_sock);
 
 	ospf6->fd = ospf6_sock;
 	/* setup global in6_addr, allspf6 and alldr6 for later use */
diff --git a/ospf6d/ospf6_proto.c b/ospf6d/ospf6_proto.c
index e60d2c7e0..4d0c4ee59 100644
--- a/ospf6d/ospf6_proto.c
+++ b/ospf6d/ospf6_proto.c
@@ -82,12 +82,16 @@ void ospf6_capability_printbuf(char capability, char *buf, int size)
 
 void ospf6_options_printbuf(uint8_t *options, char *buf, int size)
 {
-	const char *dc, *r, *n, *mc, *e, *v6;
+	const char *dc, *r, *n, *mc, *e, *v6, *af, *at, *l;
 	dc = (OSPF6_OPT_ISSET(options, OSPF6_OPT_DC) ? "DC" : "--");
 	r = (OSPF6_OPT_ISSET(options, OSPF6_OPT_R) ? "R" : "-");
 	n = (OSPF6_OPT_ISSET(options, OSPF6_OPT_N) ? "N" : "-");
 	mc = (OSPF6_OPT_ISSET(options, OSPF6_OPT_MC) ? "MC" : "--");
 	e = (OSPF6_OPT_ISSET(options, OSPF6_OPT_E) ? "E" : "-");
 	v6 = (OSPF6_OPT_ISSET(options, OSPF6_OPT_V6) ? "V6" : "--");
-	snprintf(buf, size, "%s|%s|%s|%s|%s|%s", dc, r, n, mc, e, v6);
+	af = (OSPF6_OPT_ISSET_EXT(options, OSPF6_OPT_AF) ? "AF" : "--");
+	at = (OSPF6_OPT_ISSET_EXT(options, OSPF6_OPT_AT) ? "AT" : "--");
+	l = (OSPF6_OPT_ISSET_EXT(options, OSPF6_OPT_L) ? "L" : "-");
+	snprintf(buf, size, "%s|%s|%s|-|-|%s|%s|%s|%s|%s|%s", at, l, af, dc, r,
+		 n, mc, e, v6);
 }
diff --git a/ospf6d/ospf6_proto.h b/ospf6d/ospf6_proto.h
index b98dc38b7..ea476b3a8 100644
--- a/ospf6d/ospf6_proto.h
+++ b/ospf6d/ospf6_proto.h
@@ -40,13 +40,20 @@
 
 /* OSPF options */
 /* present in HELLO, DD, LSA */
-#define OSPF6_OPT_SET(x,opt)   ((x)[2] |=  (opt))
-#define OSPF6_OPT_ISSET(x,opt) ((x)[2] &   (opt))
-#define OSPF6_OPT_CLEAR(x,opt) ((x)[2] &= ~(opt))
+#define OSPF6_OPT_SET(x, opt) ((x)[2] |= (opt))
+#define OSPF6_OPT_ISSET(x, opt) ((x)[2] & (opt))
+#define OSPF6_OPT_CLEAR(x, opt) ((x)[2] &= ~(opt))
+#define OSPF6_OPT_SET_EXT(x, opt) ((x)[1] |= (opt))
+#define OSPF6_OPT_ISSET_EXT(x, opt) ((x)[1] & (opt))
+#define OSPF6_OPT_CLEAR_EXT(x, opt) ((x)[1] &= ~(opt))
 #define OSPF6_OPT_CLEAR_ALL(x) ((x)[0] = (x)[1] = (x)[2] = 0)
 
+#define OSPF6_OPT_AT (1 << 2) /* Authentication trailer Capability */
+#define OSPF6_OPT_L (1 << 1)  /* Link local signalling Capability */
+#define OSPF6_OPT_AF (1 << 0) /* Address family Capability */
+/* 2 bits reserved for OSPFv2 migrated options */
 #define OSPF6_OPT_DC (1 << 5)   /* Demand Circuit handling Capability */
-#define OSPF6_OPT_R  (1 << 4)   /* Forwarding Capability (Any Protocol) */
+#define OSPF6_OPT_R (1 << 4)    /* Forwarding Capability (Any Protocol) */
 #define OSPF6_OPT_N  (1 << 3)   /* Handling Type-7 LSA Capability */
 #define OSPF6_OPT_MC (1 << 2)   /* Multicasting Capability */
 #define OSPF6_OPT_E  (1 << 1)   /* AS External Capability */
diff --git a/ospf6d/ospf6_route.c b/ospf6d/ospf6_route.c
index f5d60d80f..3c74ca55c 100644
--- a/ospf6d/ospf6_route.c
+++ b/ospf6d/ospf6_route.c
@@ -1168,7 +1168,7 @@ void ospf6_route_show_detail(struct vty *vty, struct ospf6_route *route,
 			     json_object *json_routes, bool use_json)
 {
 	char destination[PREFIX2STR_BUFFER], nexthop[64];
-	char area_id[16], id[16], adv_router[16], capa[16], options[16];
+	char area_id[16], id[16], adv_router[16], capa[16], options[32];
 	char pfx_options[16];
 	struct timeval now, res;
 	char duration[64];
@@ -1653,7 +1653,7 @@ static void ospf6_linkstate_show_header(struct vty *vty)
 static void ospf6_linkstate_show(struct vty *vty, struct ospf6_route *route)
 {
 	uint32_t router, id;
-	char routername[16], idname[16], rbits[16], options[16];
+	char routername[16], idname[16], rbits[16], options[32];
 
 	router = ospf6_linkstate_prefix_adv_router(&route->prefix);
 	inet_ntop(AF_INET, &router, routername, sizeof(routername));
@@ -1779,7 +1779,7 @@ void ospf6_brouter_show_header(struct vty *vty)
 void ospf6_brouter_show(struct vty *vty, struct ospf6_route *route)
 {
 	uint32_t adv_router;
-	char adv[16], rbits[16], options[16], area[16];
+	char adv[16], rbits[16], options[32], area[16];
 
 	adv_router = ospf6_linkstate_prefix_adv_router(&route->prefix);
 	inet_ntop(AF_INET, &adv_router, adv, sizeof(adv));
diff --git a/ospf6d/ospf6_top.c b/ospf6d/ospf6_top.c
index 57a55a6ef..9381fa7fa 100644
--- a/ospf6d/ospf6_top.c
+++ b/ospf6d/ospf6_top.c
@@ -54,6 +54,7 @@
 #include "ospf6_gr.h"
 #include "lib/json.h"
 #include "ospf6_nssa.h"
+#include "ospf6_auth_trailer.h"
 
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_TOP, "OSPF6 top");
 
@@ -445,6 +446,17 @@ static struct ospf6 *ospf6_create(const char *name)
 	/* Make ospf protocol socket. */
 	ospf6_serv_sock(o);
 
+	/* If sequence number is stored in persistent storage, read it.
+	 */
+	if (ospf6_auth_nvm_file_exist() == OSPF6_AUTH_FILE_EXIST) {
+		ospf6_auth_seqno_nvm_read(o);
+		o->seqnum_h = o->seqnum_h + 1;
+		ospf6_auth_seqno_nvm_update(o);
+	} else {
+		o->seqnum_l = o->seqnum_h = 0;
+		ospf6_auth_seqno_nvm_update(o);
+	}
+
 	return o;
 }
 
@@ -1386,6 +1398,10 @@ static void ospf6_show(struct vty *vty, struct ospf6 *o, json_object *json,
 		json_object_int_add(json, "numberOfAreaInRouter",
 				    listcount(o->area_list));
 
+		json_object_int_add(json, "AuthTrailerHigherSeqNo",
+				    o->seqnum_h);
+		json_object_int_add(json, "AuthTrailerLowerSeqNo", o->seqnum_l);
+
 		if (CHECK_FLAG(o->config_flags, OSPF6_LOG_ADJACENCY_CHANGES)) {
 			if (CHECK_FLAG(o->config_flags,
 				       OSPF6_LOG_ADJACENCY_DETAIL))
@@ -1466,6 +1482,10 @@ static void ospf6_show(struct vty *vty, struct ospf6 *o, json_object *json,
 		vty_out(vty, " Number of areas in this router is %u\n",
 			listcount(o->area_list));
 
+		vty_out(vty, " Authentication Sequence number info\n");
+		vty_out(vty, "  Higher sequence no %u, Lower sequence no %u\n",
+			o->seqnum_h, o->seqnum_l);
+
 		if (CHECK_FLAG(o->config_flags, OSPF6_LOG_ADJACENCY_CHANGES)) {
 			if (CHECK_FLAG(o->config_flags,
 				       OSPF6_LOG_ADJACENCY_DETAIL))
diff --git a/ospf6d/ospf6_top.h b/ospf6d/ospf6_top.h
index b9f7235b4..f06a3254a 100644
--- a/ospf6d/ospf6_top.h
+++ b/ospf6d/ospf6_top.h
@@ -228,6 +228,8 @@ struct ospf6 {
 	/* Action for aggregation of external LSAs */
 	int aggr_action;
 
+	uint32_t seqnum_l; /* lower order Sequence Number */
+	uint32_t seqnum_h; /* higher order Sequence Number */
 #define OSPF6_EXTL_AGGR_DEFAULT_DELAY 5
 	/* For ASBR summary delay timer */
 	uint16_t aggr_delay_interval;