diff --git a/isisd/isis_cli.c b/isisd/isis_cli.c
index 5ca70eab0f..b48da9312f 100644
--- a/isisd/isis_cli.c
+++ b/isisd/isis_cli.c
@@ -593,6 +593,10 @@ void cli_show_isis_overload(struct vty *vty, struct lyd_node *dnode,
 	vty_out(vty, " set-overload-bit\n");
 }
 
+#if CONFDATE > 20220119
+CPP_NOTICE(
+	"Use of `set-attached-bit` is deprecated please use attached-bit [send | receive]")
+#endif
 /*
  * XPath: /frr-isisd:isis/instance/attached
  */
@@ -600,18 +604,57 @@ DEFPY_YANG(set_attached_bit, set_attached_bit_cmd, "[no] set-attached-bit",
       "Reset attached bit\n"
       "Set attached bit to identify as L1/L2 router for inter-area traffic\n")
 {
-	nb_cli_enqueue_change(vty, "./attached", NB_OP_MODIFY,
+	vty_out(vty,
+		"set-attached-bit deprecated please use attached-bit [send | receive]\n");
+
+	return CMD_SUCCESS;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/attach-send
+ */
+DEFPY_YANG(attached_bit_send, attached_bit_send_cmd, "[no] attached-bit send",
+	   "Reset attached bit\n"
+	   "Set attached bit for inter-area traffic\n"
+	   "Set attached bit in LSP sent to L1 router\n")
+{
+	nb_cli_enqueue_change(vty, "./attach-send", NB_OP_MODIFY,
 			      no ? "false" : "true");
 
 	return nb_cli_apply_changes(vty, NULL);
 }
 
-void cli_show_isis_attached(struct vty *vty, struct lyd_node *dnode,
-			    bool show_defaults)
+void cli_show_isis_attached_send(struct vty *vty, struct lyd_node *dnode,
+				 bool show_defaults)
 {
 	if (!yang_dnode_get_bool(dnode, NULL))
 		vty_out(vty, " no");
-	vty_out(vty, " set-attached-bit\n");
+	vty_out(vty, " attached-bit send\n");
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/attach-receive-ignore
+ */
+DEFPY_YANG(
+	attached_bit_receive_ignore, attached_bit_receive_ignore_cmd,
+	"[no] attached-bit receive ignore",
+	"Reset attached bit\n"
+	"Set attach bit for inter-area traffic\n"
+	"If LSP received with attached bit set, create default route to neighbor\n"
+	"Do not process attached bit\n")
+{
+	nb_cli_enqueue_change(vty, "./attach-receive-ignore", NB_OP_MODIFY,
+			      no ? "false" : "true");
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_isis_attached_receive(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults)
+{
+	if (!yang_dnode_get_bool(dnode, NULL))
+		vty_out(vty, " no");
+	vty_out(vty, " attached-bit receive ignore\n");
 }
 
 /*
@@ -3206,6 +3249,8 @@ void isis_cli_init(void)
 
 	install_element(ISIS_NODE, &set_overload_bit_cmd);
 	install_element(ISIS_NODE, &set_attached_bit_cmd);
+	install_element(ISIS_NODE, &attached_bit_send_cmd);
+	install_element(ISIS_NODE, &attached_bit_receive_ignore_cmd);
 
 	install_element(ISIS_NODE, &metric_style_cmd);
 	install_element(ISIS_NODE, &no_metric_style_cmd);
diff --git a/isisd/isis_constants.h b/isisd/isis_constants.h
index 25eae06cb0..3d6a20ee66 100644
--- a/isisd/isis_constants.h
+++ b/isisd/isis_constants.h
@@ -140,7 +140,7 @@
  * LSP bit masks
  */
 #define LSPBIT_P   0x80
-#define LSPBIT_ATT 0x78
+#define LSPBIT_ATT 0x08 /* only use the Default ATT bit */
 #define LSPBIT_OL  0x04
 #define LSPBIT_IST 0x03
 
@@ -158,7 +158,6 @@
 #define ISIS_MASK_LSP_ATT_ERROR_BIT(x)     ((x)&0x40)
 #define ISIS_MASK_LSP_ATT_EXPENSE_BIT(x)   ((x)&0x20)
 #define ISIS_MASK_LSP_ATT_DELAY_BIT(x)     ((x)&0x10)
-#define ISIS_MASK_LSP_ATT_DEFAULT_BIT(x)   ((x)&0x8)
 
 #define LLC_LEN 3
 
diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index 47225ea2c3..4c70bd12b7 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -399,7 +399,50 @@ static void lsp_seqno_update(struct isis_lsp *lsp0)
 	return;
 }
 
-static uint8_t lsp_bits_generate(int level, int overload_bit, int attached_bit)
+static bool isis_level2_adj_up(struct isis_area *curr_area)
+{
+	struct listnode *node, *cnode;
+	struct isis_circuit *circuit;
+	struct list *adjdb;
+	struct isis_adjacency *adj;
+	struct isis *isis = curr_area->isis;
+	struct isis_area *area;
+
+	/* lookup for a Level2 adjacency up in another area */
+	for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area)) {
+		if (area->area_tag
+		    && strcmp(area->area_tag, curr_area->area_tag) == 0)
+			continue;
+
+		for (ALL_LIST_ELEMENTS_RO(area->circuit_list, cnode, circuit)) {
+			if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
+				adjdb = circuit->u.bc.adjdb[1];
+				if (adjdb && adjdb->count) {
+					for (ALL_LIST_ELEMENTS_RO(adjdb, node,
+								  adj))
+						if ((adj->level
+							     == ISIS_ADJ_LEVEL2
+						     || adj->level
+								== ISIS_ADJ_LEVEL1AND2)
+						    && adj->adj_state
+							       == ISIS_ADJ_UP)
+							return true;
+				}
+			} else if (circuit->circ_type == CIRCUIT_T_P2P
+				   && circuit->u.p2p.neighbor) {
+				adj = circuit->u.p2p.neighbor;
+				if ((adj->level == ISIS_ADJ_LEVEL2
+				     || adj->level == ISIS_ADJ_LEVEL1AND2)
+				    && adj->adj_state == ISIS_ADJ_UP)
+					return true;
+			}
+		}
+	}
+	return false;
+}
+
+static uint8_t lsp_bits_generate(int level, int overload_bit, int attached_bit,
+				 struct isis_area *area)
 {
 	uint8_t lsp_bits = 0;
 	if (level == IS_LEVEL_1)
@@ -408,8 +451,13 @@ static uint8_t lsp_bits_generate(int level, int overload_bit, int attached_bit)
 		lsp_bits = IS_LEVEL_1_AND_2;
 	if (overload_bit)
 		lsp_bits |= overload_bit;
-	if (attached_bit)
-		lsp_bits |= attached_bit;
+
+	/* only set the attach bit if we are a level-1-2 router and this is
+	 * a level-1 LSP and we have a level-2 adjacency up from another area
+	 */
+	if (area->is_type == IS_LEVEL_1_AND_2 && level == IS_LEVEL_1
+	    && attached_bit && isis_level2_adj_up(area))
+		lsp_bits |= LSPBIT_ATT;
 	return lsp_bits;
 }
 
@@ -632,13 +680,13 @@ static const char *lsp_bits2string(uint8_t lsp_bits, char *buf, size_t buf_size)
 		return " error";
 
 	/* we only focus on the default metric */
-	pos += sprintf(pos, "%d/",
-		       ISIS_MASK_LSP_ATT_DEFAULT_BIT(lsp_bits) ? 1 : 0);
+	pos += snprintf(pos, buf_size, "%d/",
+			ISIS_MASK_LSP_ATT_BITS(lsp_bits) ? 1 : 0);
 
-	pos += sprintf(pos, "%d/",
-		       ISIS_MASK_LSP_PARTITION_BIT(lsp_bits) ? 1 : 0);
+	pos += snprintf(pos, buf_size, "%d/",
+			ISIS_MASK_LSP_PARTITION_BIT(lsp_bits) ? 1 : 0);
 
-	sprintf(pos, "%d", ISIS_MASK_LSP_OL_BIT(lsp_bits) ? 1 : 0);
+	snprintf(pos, buf_size, "%d", ISIS_MASK_LSP_OL_BIT(lsp_bits) ? 1 : 0);
 
 	return buf;
 }
@@ -838,7 +886,7 @@ static struct isis_lsp *lsp_next_frag(uint8_t frag_num, struct isis_lsp *lsp0,
 
 	lsp = lsp_new(area, frag_id, lsp0->hdr.rem_lifetime, 0,
 		      lsp_bits_generate(level, area->overload_bit,
-					area->attached_bit),
+					area->attached_bit_send, area),
 		      0, lsp0, level);
 	lsp->own_lsp = 1;
 	lsp_insert(&area->lspdb[level - 1], lsp);
@@ -864,7 +912,7 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 		  area->area_tag, level);
 
 	lsp->hdr.lsp_bits = lsp_bits_generate(level, area->overload_bit,
-					      area->attached_bit);
+					      area->attached_bit_send, area);
 
 	lsp_add_auth(lsp);
 
@@ -1223,10 +1271,10 @@ int lsp_generate(struct isis_area *area, int level)
 				       oldlsp->hdr.lsp_id);
 	}
 	rem_lifetime = lsp_rem_lifetime(area, level);
-	newlsp =
-		lsp_new(area, lspid, rem_lifetime, seq_num,
-			area->is_type | area->overload_bit | area->attached_bit,
-			0, NULL, level);
+	newlsp = lsp_new(area, lspid, rem_lifetime, seq_num,
+			 lsp_bits_generate(area->is_type, area->overload_bit,
+					   area->attached_bit_send, area),
+			 0, NULL, level);
 	newlsp->area = area;
 	newlsp->own_lsp = 1;
 
@@ -1310,8 +1358,9 @@ static int lsp_regenerate(struct isis_area *area, int level)
 			continue;
 		}
 
-		frag->hdr.lsp_bits = lsp_bits_generate(
-			level, area->overload_bit, area->attached_bit);
+		frag->hdr.lsp_bits =
+			lsp_bits_generate(level, area->overload_bit,
+					  area->attached_bit_send, area);
 		/* Set the lifetime values of all the fragments to the same
 		 * value,
 		 * so that no fragment expires before the lsp is refreshed.
@@ -1518,8 +1567,8 @@ static void lsp_build_pseudo(struct isis_lsp *lsp, struct isis_circuit *circuit,
 
 	lsp->level = level;
 	/* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
-	lsp->hdr.lsp_bits =
-		lsp_bits_generate(level, 0, circuit->area->attached_bit);
+	lsp->hdr.lsp_bits = lsp_bits_generate(
+		level, 0, circuit->area->attached_bit_send, area);
 
 	/*
 	 * add self to IS neighbours
@@ -1617,8 +1666,10 @@ int lsp_generate_pseudo(struct isis_circuit *circuit, int level)
 	rem_lifetime = lsp_rem_lifetime(circuit->area, level);
 	/* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
 	lsp = lsp_new(circuit->area, lsp_id, rem_lifetime, 1,
-		      circuit->area->is_type | circuit->area->attached_bit, 0,
-		      NULL, level);
+		      lsp_bits_generate(circuit->area->is_type, 0,
+					circuit->area->attached_bit_send,
+					circuit->area),
+		      0, NULL, level);
 	lsp->area = circuit->area;
 
 	lsp_build_pseudo(lsp, circuit, level);
diff --git a/isisd/isis_nb.c b/isisd/isis_nb.c
index a02e6a45b1..6d46e6b67e 100644
--- a/isisd/isis_nb.c
+++ b/isisd/isis_nb.c
@@ -59,10 +59,23 @@ const struct frr_yang_module_info frr_isisd_info = {
 				.modify = isis_instance_dynamic_hostname_modify,
 			},
 		},
+		{
+			.xpath = "/frr-isisd:isis/instance/attach-send",
+			.cbs = {
+				.cli_show = cli_show_isis_attached_send,
+				.modify = isis_instance_attached_send_modify,
+			},
+		},
+		{
+			.xpath = "/frr-isisd:isis/instance/attach-receive-ignore",
+			.cbs = {
+				.cli_show = cli_show_isis_attached_receive,
+				.modify = isis_instance_attached_receive_modify,
+			},
+		},
 		{
 			.xpath = "/frr-isisd:isis/instance/attached",
 			.cbs = {
-				.cli_show = cli_show_isis_attached,
 				.modify = isis_instance_attached_modify,
 			},
 		},
diff --git a/isisd/isis_nb.h b/isisd/isis_nb.h
index 679bc6345d..8ecd8134e6 100644
--- a/isisd/isis_nb.h
+++ b/isisd/isis_nb.h
@@ -34,6 +34,8 @@ int isis_instance_is_type_modify(struct nb_cb_modify_args *args);
 int isis_instance_area_address_create(struct nb_cb_create_args *args);
 int isis_instance_area_address_destroy(struct nb_cb_destroy_args *args);
 int isis_instance_dynamic_hostname_modify(struct nb_cb_modify_args *args);
+int isis_instance_attached_send_modify(struct nb_cb_modify_args *args);
+int isis_instance_attached_receive_modify(struct nb_cb_modify_args *args);
 int isis_instance_attached_modify(struct nb_cb_modify_args *args);
 int isis_instance_overload_modify(struct nb_cb_modify_args *args);
 int isis_instance_metric_style_modify(struct nb_cb_modify_args *args);
@@ -424,8 +426,10 @@ void cli_show_isis_is_type(struct vty *vty, struct lyd_node *dnode,
 			   bool show_defaults);
 void cli_show_isis_dynamic_hostname(struct vty *vty, struct lyd_node *dnode,
 				    bool show_defaults);
-void cli_show_isis_attached(struct vty *vty, struct lyd_node *dnode,
-			    bool show_defaults);
+void cli_show_isis_attached_send(struct vty *vty, struct lyd_node *dnode,
+				 bool show_defaults);
+void cli_show_isis_attached_receive(struct vty *vty, struct lyd_node *dnode,
+				    bool show_defaults);
 void cli_show_isis_overload(struct vty *vty, struct lyd_node *dnode,
 			    bool show_defaults);
 void cli_show_isis_metric_style(struct vty *vty, struct lyd_node *dnode,
diff --git a/isisd/isis_nb_config.c b/isisd/isis_nb_config.c
index ed0fea8824..45bbc9737b 100644
--- a/isisd/isis_nb_config.c
+++ b/isisd/isis_nb_config.c
@@ -272,9 +272,9 @@ int isis_instance_dynamic_hostname_modify(struct nb_cb_modify_args *args)
 }
 
 /*
- * XPath: /frr-isisd:isis/instance/attached
+ * XPath: /frr-isisd:isis/instance/attach-send
  */
-int isis_instance_attached_modify(struct nb_cb_modify_args *args)
+int isis_instance_attached_send_modify(struct nb_cb_modify_args *args)
 {
 	struct isis_area *area;
 	bool attached;
@@ -284,11 +284,37 @@ int isis_instance_attached_modify(struct nb_cb_modify_args *args)
 
 	area = nb_running_get_entry(args->dnode, NULL, true);
 	attached = yang_dnode_get_bool(args->dnode, NULL);
-	isis_area_attached_bit_set(area, attached);
+	isis_area_attached_bit_send_set(area, attached);
 
 	return NB_OK;
 }
 
+/*
+ * XPath: /frr-isisd:isis/instance/attach-receive-ignore
+ */
+int isis_instance_attached_receive_modify(struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	bool attached;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	attached = yang_dnode_get_bool(args->dnode, NULL);
+	isis_area_attached_bit_receive_set(area, attached);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-isisd:isis/instance/attached
+ */
+int isis_instance_attached_modify(struct nb_cb_modify_args *args)
+{
+	return NB_OK;
+}
+
 /*
  * XPath: /frr-isisd:isis/instance/overload
  */
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index 72de5d6543..2d68aaa9ed 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -729,8 +729,8 @@ static int process_hello(uint8_t pdu_type, struct isis_circuit *circuit,
 
 	if (!memcmp(iih.sys_id, circuit->isis->sysid, ISIS_SYS_ID_LEN)) {
 		zlog_warn(
-			"ISIS-Adj (%s): Received IIH with own sysid - discard",
-			circuit->area->area_tag);
+			"ISIS-Adj (%s): Received IIH with own sysid on %s - discard",
+			circuit->area->area_tag, circuit->interface->name);
 		circuit->rej_adjacencies++;
 #ifndef FABRICD
 		isis_notif_reject_adjacency(
diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index dee082fce1..ec0313f21e 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -1046,6 +1046,32 @@ lspfragloop:
 	}
 
 end:
+
+	/* if attach bit set and we are a level-1 router
+	 * and attach-bit-rcv-ignore is not configured
+	 * add a default route toward this neighbor
+	 */
+	if ((lsp->hdr.lsp_bits & LSPBIT_ATT) == LSPBIT_ATT
+	    && !spftree->area->attached_bit_rcv_ignore
+	    && spftree->area->is_type == IS_LEVEL_1) {
+		struct prefix_pair ip_info = { {0} };
+		if (IS_DEBUG_SPF_EVENTS)
+			zlog_debug("ISIS-Spf (%s): add default %s route",
+				   rawlspid_print(lsp->hdr.lsp_id),
+				   spftree->family == AF_INET ? "ipv4"
+							      : "ipv6");
+
+		if (spftree->family == AF_INET) {
+			ip_info.dest.family = AF_INET;
+			vtype = VTYPE_IPREACH_INTERNAL;
+		} else {
+			ip_info.dest.family = AF_INET6;
+			vtype = VTYPE_IP6REACH_INTERNAL;
+		}
+		process_N(spftree, vtype, &ip_info, cost, depth + 1, NULL,
+			  parent);
+	}
+
 	if (fragnode == NULL)
 		fragnode = listhead(lsp->lspu.frags);
 	else
diff --git a/isisd/isisd.c b/isisd/isisd.c
index eabebab4e0..d45690f4dc 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -316,6 +316,11 @@ struct isis_area *isis_area_create(const char *area_tag, const char *vrf_name)
 		"/frr-isisd:isis/instance/fast-reroute/level-1/lfa/load-sharing");
 	area->lfa_load_sharing[1] = yang_get_default_bool(
 		"/frr-isisd:isis/instance/fast-reroute/level-2/lfa/load-sharing");
+	area->attached_bit_send =
+		yang_get_default_bool("/frr-isisd:isis/instance/attach-send");
+	area->attached_bit_rcv_ignore = yang_get_default_bool(
+		"/frr-isisd:isis/instance/attach-receive-ignore");
+
 #else
 	area->max_lsp_lifetime[0] = DEFAULT_LSP_LIFETIME;    /* 1200 */
 	area->max_lsp_lifetime[1] = DEFAULT_LSP_LIFETIME;    /* 1200 */
@@ -332,6 +337,8 @@ struct isis_area *isis_area_create(const char *area_tag, const char *vrf_name)
 	area->lsp_mtu = DEFAULT_LSP_MTU;
 	area->lfa_load_sharing[0] = true;
 	area->lfa_load_sharing[1] = true;
+	area->attached_bit_send = true;
+	area->attached_bit_rcv_ignore = false;
 #endif /* ifndef FABRICD */
 	area->lfa_priority_limit[0] = SPF_PREFIX_PRIO_LOW;
 	area->lfa_priority_limit[1] = SPF_PREFIX_PRIO_LOW;
@@ -2547,12 +2554,21 @@ void isis_area_overload_bit_set(struct isis_area *area, bool overload_bit)
 #endif /* ifndef FABRICD */
 }
 
-void isis_area_attached_bit_set(struct isis_area *area, bool attached_bit)
+void isis_area_attached_bit_send_set(struct isis_area *area, bool attached_bit)
 {
-	char new_attached_bit = attached_bit ? LSPBIT_ATT : 0;
 
-	if (new_attached_bit != area->attached_bit) {
-		area->attached_bit = new_attached_bit;
+	if (attached_bit != area->attached_bit_send) {
+		area->attached_bit_send = attached_bit;
+		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 1);
+	}
+}
+
+void isis_area_attached_bit_receive_set(struct isis_area *area,
+					bool attached_bit)
+{
+
+	if (attached_bit != area->attached_bit_rcv_ignore) {
+		area->attached_bit_rcv_ignore = attached_bit;
 		lsp_regenerate_schedule(area, IS_LEVEL_1 | IS_LEVEL_2, 1);
 	}
 }
diff --git a/isisd/isisd.h b/isisd/isisd.h
index 9b903eed48..a09f741522 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -169,7 +169,8 @@ struct isis_area {
 	/* are we overloaded? */
 	char overload_bit;
 	/* L1/L2 router identifier for inter-area traffic */
-	char attached_bit;
+	char attached_bit_send;
+	char attached_bit_rcv_ignore;
 	uint16_t lsp_refresh[ISIS_LEVELS];
 	/* minimum time allowed before lsp retransmission */
 	uint16_t lsp_gen_interval[ISIS_LEVELS];
@@ -253,7 +254,9 @@ void isis_area_invalidate_routes(struct isis_area *area, int levels);
 void isis_area_verify_routes(struct isis_area *area);
 
 void isis_area_overload_bit_set(struct isis_area *area, bool overload_bit);
-void isis_area_attached_bit_set(struct isis_area *area, bool attached_bit);
+void isis_area_attached_bit_send_set(struct isis_area *area, bool attached_bit);
+void isis_area_attached_bit_receive_set(struct isis_area *area,
+					bool attached_bit);
 void isis_area_dynhostname_set(struct isis_area *area, bool dynhostname);
 void isis_area_metricstyle_set(struct isis_area *area, bool old_metric,
 			       bool new_metric);
diff --git a/yang/frr-isisd.yang b/yang/frr-isisd.yang
index 812dd4159d..8757ab6b8b 100644
--- a/yang/frr-isisd.yang
+++ b/yang/frr-isisd.yang
@@ -1043,9 +1043,24 @@ module frr-isisd {
           "Dynamic hostname support for IS-IS.";
       }
 
+      leaf attach-send {
+        type boolean;
+        default "true";
+        description
+          "If true, attached bits are sent in LSP if L1/L2 router for inter-area traffic.";
+      }
+
+      leaf attach-receive-ignore {
+        type boolean;
+        default "false";
+        description
+          "If false, attached bits received in LSP, cause default route add, if L1 router for inter-area traffic.";
+      }
+
       leaf attached {
         type boolean;
         default "false";
+	status deprecated;
         description
           "If true, identify as L1/L2 router for inter-area traffic.";
       }