diff --git a/pimd/pim_cmd.c b/pimd/pim_cmd.c
index a34fb344feb5..f30fa6d379bd 100644
--- a/pimd/pim_cmd.c
+++ b/pimd/pim_cmd.c
@@ -6778,12 +6778,14 @@ ALIAS(no_ip_pim_bfd, no_ip_pim_bfd_param_cmd,
 #endif /* !HAVE_BFDD */
 
 DEFPY(pim_msdp_peer, pim_msdp_peer_cmd,
-      "msdp peer A.B.C.D$peer source A.B.C.D$source",
+      "msdp peer A.B.C.D$peer source A.B.C.D$source [as (1-4294967295)$asn]",
       CFG_MSDP_STR
       "Configure MSDP peer\n"
       "Peer IP address\n"
       "Source address for TCP connection\n"
-      "Local IP address\n")
+      "Local IP address\n"
+      "BGP Autonomous System peer information\n"
+      "BGP Autonomous System peer number\n")
 {
 	char msdp_peer_source_xpath[XPATH_MAXLEN];
 
@@ -6791,6 +6793,11 @@ DEFPY(pim_msdp_peer, pim_msdp_peer_cmd,
 		 "./msdp-peer[peer-ip='%s']/source-ip", peer_str);
 	nb_cli_enqueue_change(vty, msdp_peer_source_xpath, NB_OP_MODIFY,
 			      source_str);
+	if (asn_str) {
+		snprintf(msdp_peer_source_xpath, sizeof(msdp_peer_source_xpath),
+			 "./msdp-peer[peer-ip='%s']/as", peer_str);
+		nb_cli_enqueue_change(vty, msdp_peer_source_xpath, NB_OP_MODIFY, asn_str);
+	}
 
 	return nb_cli_apply_changes(vty, NULL);
 }
@@ -7795,7 +7802,7 @@ static void ip_msdp_show_peers(struct pim_instance *pim, struct vty *vty,
 		json = json_object_new_object();
 	} else {
 		vty_out(vty,
-			"Peer                       Local        State    Uptime   SaCnt\n");
+			"Peer                       Local        State    Uptime   SaCnt    AS\n");
 	}
 
 	for (ALL_LIST_ELEMENTS_RO(pim->msdp.peer_list, mpnode, mp)) {
@@ -7817,10 +7824,17 @@ static void ip_msdp_show_peers(struct pim_instance *pim, struct vty *vty,
 			json_object_string_add(json_row, "state", state_str);
 			json_object_string_add(json_row, "upTime", timebuf);
 			json_object_int_add(json_row, "saCount", mp->sa_cnt);
+			if (mp->asn)
+				json_object_int_add(json_row, "asn", mp->asn);
+
 			json_object_object_add(json, peer_str, json_row);
 		} else {
-			vty_out(vty, "%-15s  %15s  %11s  %8s  %6d\n", peer_str,
-				local_str, state_str, timebuf, mp->sa_cnt);
+			vty_out(vty, "%-15s  %15s  %11s  %8s  %6d", peer_str, local_str, state_str,
+				timebuf, mp->sa_cnt);
+			if (mp->asn)
+				vty_out(vty, " %5d\n", mp->asn);
+			else
+				vty_out(vty, " %5s\n", "-");
 		}
 	}
 
@@ -8093,6 +8107,7 @@ static void ip_msdp_show_sa_entry_detail(struct pim_msdp_sa *sa,
 	char spt_str[8];
 	char local_str[8];
 	char statetimer[PIM_MSDP_TIMER_STRLEN];
+	uint32_t asn = pim_msdp_sa_asn(sa);
 	int64_t now;
 	json_object *json_group = NULL;
 	json_object *json_row = NULL;
@@ -8135,6 +8150,9 @@ static void ip_msdp_show_sa_entry_detail(struct pim_msdp_sa *sa,
 		json_object_string_add(json_row, "sptSetup", spt_str);
 		json_object_string_add(json_row, "upTime", timebuf);
 		json_object_string_add(json_row, "stateTimer", statetimer);
+		if (asn)
+			json_object_int_add(json_row, "asn", asn);
+
 		json_object_object_add(json_group, src_str, json_row);
 	} else {
 		vty_out(vty, "SA : %s\n", sa->sg_str);
@@ -8144,6 +8162,9 @@ static void ip_msdp_show_sa_entry_detail(struct pim_msdp_sa *sa,
 		vty_out(vty, "  SPT Setup   : %s\n", spt_str);
 		vty_out(vty, "  Uptime      : %s\n", timebuf);
 		vty_out(vty, "  State Timer : %s\n", statetimer);
+		if (asn)
+			vty_out(vty, "  BGP/AS      : %u\n", asn);
+
 		vty_out(vty, "\n");
 	}
 }
diff --git a/pimd/pim_msdp.c b/pimd/pim_msdp.c
index 5e5ee5e91f27..67bcab8eeda2 100644
--- a/pimd/pim_msdp.c
+++ b/pimd/pim_msdp.c
@@ -65,6 +65,16 @@ void pim_msdp_originator_id(struct pim_instance *pim, const struct prefix *group
 	}
 }
 
+uint32_t pim_msdp_sa_asn(const struct pim_msdp_sa *sa)
+{
+	struct pim_msdp_peer *peer = pim_msdp_peer_find(sa->pim, sa->peer);
+
+	if (peer == NULL)
+		return 0;
+
+	return peer->asn;
+}
+
 /************************ SA cache management ******************************/
 /* RFC-3618:Sec-5.1 - global active source advertisement timer */
 static void pim_msdp_sa_adv_timer_cb(struct event *t)
@@ -706,7 +716,7 @@ bool pim_msdp_peer_rpf_check(struct pim_msdp_peer *mp, struct in_addr rp)
 	}
 
 	/* check if the MSDP peer is the nexthop for the RP */
-	if (pim_nht_lookup(mp->pim, &nexthop, rp, 0) &&
+	if (pim_route_lookup(mp->pim, rp, mp->asn, &nexthop) &&
 	    nexthop.mrib_nexthop_addr.s_addr == mp->peer.s_addr) {
 		return true;
 	}
@@ -1332,8 +1342,10 @@ bool pim_msdp_peer_config_write(struct vty *vty, struct pim_instance *pim)
 		if (mp->flags & PIM_MSDP_PEERF_IN_GROUP)
 			continue;
 
-		vty_out(vty, " msdp peer %pI4 source %pI4\n", &mp->peer,
-			&mp->local);
+		vty_out(vty, " msdp peer %pI4 source %pI4", &mp->peer, &mp->local);
+		if (mp->asn)
+			vty_out(vty, " as %u", mp->asn);
+		vty_out(vty, "\n");
 
 		if (mp->auth_type == MSDP_AUTH_MD5)
 			vty_out(vty, " msdp peer %pI4 password %s\n", &mp->peer,
diff --git a/pimd/pim_msdp.h b/pimd/pim_msdp.h
index 4edb6e6166ec..33af2d0b6be8 100644
--- a/pimd/pim_msdp.h
+++ b/pimd/pim_msdp.h
@@ -155,6 +155,9 @@ struct pim_msdp_peer {
 
 	/** SA maximum amount. */
 	uint32_t sa_limit;
+
+	/** BGP AS number for RPF check. */
+	uint32_t asn;
 };
 
 struct pim_msdp_mg_mbr {
@@ -253,6 +256,7 @@ void pim_msdp_sa_ref(struct pim_instance *pim, struct pim_msdp_peer *mp,
 		     pim_sgaddr *sg, struct in_addr rp);
 void pim_msdp_sa_local_update(struct pim_upstream *up);
 void pim_msdp_sa_local_del(struct pim_instance *pim, pim_sgaddr *sg);
+uint32_t pim_msdp_sa_asn(const struct pim_msdp_sa *sa);
 void pim_msdp_i_am_rp_changed(struct pim_instance *pim);
 bool pim_msdp_peer_rpf_check(struct pim_msdp_peer *mp, struct in_addr rp);
 void pim_msdp_up_join_state_changed(struct pim_instance *pim,
diff --git a/pimd/pim_nb.c b/pimd/pim_nb.c
index b55541b81026..ab002cceb3b3 100644
--- a/pimd/pim_nb.c
+++ b/pimd/pim_nb.c
@@ -222,6 +222,13 @@ const struct frr_yang_module_info frr_pim_info = {
 				.destroy = pim_msdp_peer_sa_limit_destroy,
 			}
 		},
+		{
+			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-peer/as",
+			.cbs = {
+				.modify = pim_msdp_peer_as_modify,
+				.destroy = pim_msdp_peer_as_destroy,
+			}
+		},
 		{
 			.xpath = "/frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/mlag",
 			.cbs = {
diff --git a/pimd/pim_nb.h b/pimd/pim_nb.h
index a5ef6ad60a8f..660ece67fa93 100644
--- a/pimd/pim_nb.h
+++ b/pimd/pim_nb.h
@@ -80,6 +80,8 @@ int pim_msdp_peer_authentication_key_modify(struct nb_cb_modify_args *args);
 int pim_msdp_peer_authentication_key_destroy(struct nb_cb_destroy_args *args);
 int pim_msdp_peer_sa_limit_modify(struct nb_cb_modify_args *args);
 int pim_msdp_peer_sa_limit_destroy(struct nb_cb_destroy_args *args);
+int pim_msdp_peer_as_modify(struct nb_cb_modify_args *args);
+int pim_msdp_peer_as_destroy(struct nb_cb_destroy_args *args);
 int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mlag_create(
 	struct nb_cb_create_args *args);
 int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mlag_destroy(
diff --git a/pimd/pim_nb_config.c b/pimd/pim_nb_config.c
index b55d08bab9c9..d6de39a81bbb 100644
--- a/pimd/pim_nb_config.c
+++ b/pimd/pim_nb_config.c
@@ -1023,6 +1023,8 @@ pim6_msdp_err(pim_msdp_peer_sa_filter_out_modify, nb_cb_modify_args);
 pim6_msdp_err(pim_msdp_peer_sa_filter_out_destroy, nb_cb_destroy_args);
 pim6_msdp_err(pim_msdp_peer_sa_limit_modify, nb_cb_modify_args);
 pim6_msdp_err(pim_msdp_peer_sa_limit_destroy, nb_cb_destroy_args);
+pim6_msdp_err(pim_msdp_peer_as_modify, nb_cb_modify_args);
+pim6_msdp_err(pim_msdp_peer_as_destroy, nb_cb_destroy_args);
 pim6_msdp_err(
 	routing_control_plane_protocols_control_plane_protocol_pim_address_family_msdp_peer_source_ip_modify,
 	nb_cb_modify_args);
@@ -1677,6 +1679,47 @@ int pim_msdp_peer_sa_limit_destroy(struct nb_cb_destroy_args *args)
 
 	return NB_OK;
 }
+
+/*
+ * XPath: /frr-routing:routing/control-plane-protocols/control-plane-protocol/frr-pim:pim/address-family/msdp-peer/as
+ */
+int pim_msdp_peer_as_modify(struct nb_cb_modify_args *args)
+{
+	struct pim_msdp_peer *peer;
+
+	switch (args->event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	case NB_EV_APPLY:
+		peer = nb_running_get_entry(args->dnode, NULL, true);
+		peer->asn = yang_dnode_get_uint32(args->dnode, NULL);
+		break;
+	}
+
+	return NB_OK;
+}
+
+int pim_msdp_peer_as_destroy(struct nb_cb_destroy_args *args)
+{
+	struct pim_msdp_peer *peer;
+
+	switch (args->event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	case NB_EV_APPLY:
+		peer = nb_running_get_entry(args->dnode, NULL, true);
+		peer->asn = 0;
+		break;
+	}
+
+	return NB_OK;
+}
 #endif /* PIM_IPV != 6 */
 
 /*
diff --git a/pimd/pim_rpf.c b/pimd/pim_rpf.c
index 75e921382549..0581670392a3 100644
--- a/pimd/pim_rpf.c
+++ b/pimd/pim_rpf.c
@@ -257,3 +257,134 @@ int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2)
 
 	return 0;
 }
+
+bool pim_route_lookup(struct pim_instance *pim, pim_addr addr, uint32_t asn, struct pim_nexthop *pn)
+{
+	struct interface *ifp;
+	struct zroute_info *ri;
+	struct zroute_nh_info *rni;
+	bool found = false;
+
+	/* Zero out pim next hop response.*/
+	memset(pn, 0, sizeof(*pn));
+
+	/* Search route information. */
+	ri = zclient_route_lookup(pim, &addr);
+	if (ri == NULL) {
+		if (PIM_DEBUG_ZEBRA)
+			zlog_debug("%s: could not find route for address %pPA", __func__, &addr);
+		return false;
+	}
+
+	/*
+	 * AS check (in case AS number was provided).
+	 *
+	 * This code path checks for the following MSDP rule:
+	 *
+	 * > For a direct peering inter-domain environment to be successful, the
+	 * > first AS in the MBGP best path to the originating RP should be the
+	 * > same as the AS of the MSDP peer.
+	 *
+	 * RFC 4611 Section 2.1. Peering between PIM Border Routers.
+	 */
+	if (asn) {
+		long long first_asn;
+
+		/*
+		 * We expect a BGP route so if no AS Path information is
+		 * available it means this is not a BGP route.
+		 */
+		if (ri->ri_type != ZEBRA_ROUTE_BGP) {
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: expected BGP route for %pPA (got %d)", __func__,
+					   &addr, ri->ri_type);
+			goto free_and_exit;
+		}
+
+		errno = 0;
+		first_asn = strtoll((char *)ri->ri_opaque, NULL, 10);
+		/* Check for number conversion failures. */
+		if (first_asn == LLONG_MIN || first_asn == LLONG_MAX) {
+			zlog_warn("%s: AS number overflow/underflow %s", __func__, ri->ri_opaque);
+			goto free_and_exit;
+		}
+		if (first_asn == 0 && errno != 0) {
+			zlog_warn("%s: AS number conversion failed: %s", __func__, strerror(errno));
+			goto free_and_exit;
+		}
+
+		/* AS did not match. */
+		if (first_asn != asn) {
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: next hop AS did not match for address %pPA (%u != %lld)",
+					   __func__, &addr, asn, first_asn);
+			goto free_and_exit;
+		}
+
+		/* Proceed to validate next hop. */
+		if (PIM_DEBUG_ZEBRA)
+			zlog_debug("%s: next hop AS matched for address %pPA (AS %u)", __func__,
+				   &addr, asn);
+	}
+
+	SLIST_FOREACH (rni, &ri->ri_nhlist, rni_entry) {
+		ifp = if_lookup_by_index(rni->rni_ifindex, pim->vrf->vrf_id);
+		if (ifp == NULL) {
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: could not find interface for ifindex %d (address %pPA)",
+					   __func__, rni->rni_ifindex, &addr);
+			continue;
+		}
+		if (ifp->info == NULL) {
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %pPA)",
+					   __func__, ifp->name, rni->rni_ifindex, &addr);
+			continue;
+		}
+
+		/* Fill next hop parameter and return. */
+		switch (rni->rni_type) {
+		case NEXTHOP_TYPE_IPV4:
+		case NEXTHOP_TYPE_IPV4_IFINDEX:
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: found nexthop %pI4 for address %pPA: interface %s ifindex=%d metric=%d pref=%d",
+					   __func__, &rni->rni_addr.v4, &addr, ifp->name,
+					   rni->rni_ifindex, ri->ri_metric, ri->ri_distance);
+
+#if PIM_IPV == 4
+			pn->mrib_nexthop_addr = rni->rni_addr.v4;
+#endif
+			break;
+		case NEXTHOP_TYPE_IPV6:
+		case NEXTHOP_TYPE_IPV6_IFINDEX:
+			if (PIM_DEBUG_ZEBRA)
+				zlog_debug("%s: found nexthop %pI6 for address %pPA: interface %s ifindex=%d metric=%d pref=%d",
+					   __func__, &rni->rni_addr, &addr, ifp->name,
+					   rni->rni_ifindex, ri->ri_metric, ri->ri_distance);
+
+#if PIM_IPV == 6
+			pn->mrib_nexthop_addr = rni->rni_addr.v6;
+#endif
+			break;
+		case NEXTHOP_TYPE_IFINDEX:
+			break;
+
+		default:
+			zlog_warn("%s: invalid next hop address type %d", __func__, rni->rni_type);
+			continue;
+		}
+
+		pn->interface = ifp;
+		pn->mrib_metric_preference = ri->ri_distance;
+		pn->mrib_route_metric = ri->ri_metric;
+		pn->last_lookup = addr;
+		pn->last_lookup_time = pim_time_monotonic_usec();
+
+		found = true;
+		break;
+	}
+
+free_and_exit:
+	zroute_info_free(&ri);
+	return found;
+}
diff --git a/pimd/pim_rpf.h b/pimd/pim_rpf.h
index 84d6b7f6c278..c1bada9d34f0 100644
--- a/pimd/pim_rpf.h
+++ b/pimd/pim_rpf.h
@@ -62,4 +62,5 @@ int pim_rpf_addr_is_inaddr_any(struct pim_rpf *rpf);
 
 int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2);
 void pim_rpf_set_refresh_time(struct pim_instance *pim);
+bool pim_route_lookup(struct pim_instance *pim, pim_addr addr, uint32_t asn, struct pim_nexthop *pn);
 #endif /* PIM_RPF_H */
diff --git a/pimd/pim_zlookup.c b/pimd/pim_zlookup.c
index febc595ad4c4..ef2cc3ff1b1a 100644
--- a/pimd/pim_zlookup.c
+++ b/pimd/pim_zlookup.c
@@ -559,6 +559,27 @@ int zclient_lookup_nexthop(struct pim_instance *pim,
 	return -2;
 }
 
+struct zroute_info *zclient_route_lookup(struct pim_instance *pim, const pim_addr *addr)
+{
+	if (zlookup->sock < 0) {
+		flog_err(EC_LIB_ZAPI_SOCKET, "%s: zclient lookup socket is not connected", __func__);
+		zclient_lookup_failed(zlookup);
+		return NULL;
+	}
+
+	if (pim->vrf->vrf_id == VRF_UNKNOWN) {
+		zlog_notice("%s: VRF: %s does not fully exist yet, delaying lookup", __func__,
+			    pim->vrf->name);
+		return NULL;
+	}
+
+#if PIM_IPV == 4
+	return zapi_route_lookup(zlookup, pim->vrf->vrf_id, AF_INET, addr);
+#else
+	return zapi_route_lookup(zlookup, pim->vrf->vrf_id, AF_INET6, addr);
+#endif
+}
+
 void pim_zlookup_show_ip_multicast(struct vty *vty)
 {
 	vty_out(vty, "Zclient lookup socket: ");
diff --git a/pimd/pim_zlookup.h b/pimd/pim_zlookup.h
index c9461eb7e3df..1bf7db60eede 100644
--- a/pimd/pim_zlookup.h
+++ b/pimd/pim_zlookup.h
@@ -35,4 +35,15 @@ int zclient_lookup_nexthop(struct pim_instance *pim,
 void pim_zlookup_show_ip_multicast(struct vty *vty);
 
 int pim_zlookup_sg_statistics(struct channel_oil *c_oil);
+
+/**
+ * Asks zebra to lookup for a route and return its information.
+ *
+ * \param pim PIM instance information.
+ * \param addr route address.
+ * \param type route type (e.g. if none specific then `ZEBRA_ROUTE_ALL`).
+ * \note call `zroute_info_free` after using the results.
+ */
+struct zroute_info *zclient_route_lookup(struct pim_instance *pim, const pim_addr *addr);
+
 #endif /* PIM_ZLOOKUP_H */