diff --git a/src/core/ndisc/nm-ndisc.c b/src/core/ndisc/nm-ndisc.c
index 1a2bf48072..758ce0a05c 100644
--- a/src/core/ndisc/nm-ndisc.c
+++ b/src/core/ndisc/nm-ndisc.c
@@ -109,7 +109,8 @@ nm_ndisc_data_to_l3cd(NMDedupMultiIndex        *multi_idx,
                       int                       ifindex,
                       const NMNDiscData        *rdata,
                       NMSettingIP6ConfigPrivacy ip6_privacy,
-                      NMUtilsIPv6IfaceId       *token)
+                      NMUtilsIPv6IfaceId       *token,
+                      const char               *network_id)
 {
     nm_auto_unref_l3cd_init NML3ConfigData *l3cd = NULL;
     guint32                                 ifa_flags;
@@ -218,6 +219,8 @@ nm_ndisc_data_to_l3cd(NMDedupMultiIndex        *multi_idx,
     nm_l3_config_data_set_ip6_mtu(l3cd, rdata->mtu);
     if (token)
         nm_l3_config_data_set_ip6_token(l3cd, *token);
+    if (network_id)
+        nm_l3_config_data_set_network_id(l3cd, network_id);
 
     return g_steal_pointer(&l3cd);
 }
@@ -437,7 +440,8 @@ nm_ndisc_emit_config_change(NMNDisc *self, NMNDiscConfigMap changed)
                                  nm_l3cfg_get_ifindex(priv->config.l3cfg),
                                  rdata,
                                  priv->config.ip6_privacy,
-                                 priv->iid_is_token ? &priv->iid : NULL);
+                                 priv->iid_is_token ? &priv->iid : NULL,
+                                 priv->config.network_id);
     l3cd = nm_l3_config_data_seal(l3cd);
 
     if (!nm_l3_config_data_equal(priv->l3cd, l3cd))
diff --git a/src/core/ndisc/nm-ndisc.h b/src/core/ndisc/nm-ndisc.h
index 8f1a12a267..eda1e696d9 100644
--- a/src/core/ndisc/nm-ndisc.h
+++ b/src/core/ndisc/nm-ndisc.h
@@ -282,6 +282,7 @@ struct _NML3ConfigData *nm_ndisc_data_to_l3cd(NMDedupMultiIndex        *multi_id
                                               int                       ifindex,
                                               const NMNDiscData        *rdata,
                                               NMSettingIP6ConfigPrivacy ip6_privacy,
-                                              NMUtilsIPv6IfaceId       *token);
+                                              NMUtilsIPv6IfaceId       *token,
+                                              const char               *network_id);
 
 #endif /* __NETWORKMANAGER_NDISC_H__ */
diff --git a/src/core/nm-core-utils.h b/src/core/nm-core-utils.h
index fdfed5f65d..7c5612da25 100644
--- a/src/core/nm-core-utils.h
+++ b/src/core/nm-core-utils.h
@@ -304,6 +304,7 @@ typedef enum {
     NM_UTILS_STABLE_TYPE_STABLE_ID = 1,
     NM_UTILS_STABLE_TYPE_GENERATED = 2,
     NM_UTILS_STABLE_TYPE_RANDOM    = 3,
+    NM_UTILS_STABLE_TYPE_CLAT      = 4,
 } NMUtilsStableType;
 
 #define NM_UTILS_STABLE_TYPE_NONE ((NMUtilsStableType) - 1)
diff --git a/src/core/nm-l3-config-data.c b/src/core/nm-l3-config-data.c
index 666aa8a38c..05823b5ae2 100644
--- a/src/core/nm-l3-config-data.c
+++ b/src/core/nm-l3-config-data.c
@@ -121,6 +121,7 @@ struct _NML3ConfigData {
     NMSettingConnectionLlmnr      llmnr;
     NMSettingConnectionDnsOverTls dns_over_tls;
     NMUtilsIPv6IfaceId            ip6_token;
+    NMRefString                  *network_id;
 
     NML3ConfigDatFlags flags;
 
@@ -592,6 +593,10 @@ nm_l3_config_data_log(const NML3ConfigData *self,
            nm_utils_inet6_interface_identifier_to_token(&self->ip6_token, sbuf_addr));
     }
 
+    if (self->network_id) {
+        _L("network-id: %s", self->network_id->str);
+    }
+
     if (self->metered != NM_TERNARY_DEFAULT)
         _L("metered: %s", self->metered ? "yes" : "no");
 
@@ -810,6 +815,7 @@ nm_l3_config_data_unref(const NML3ConfigData *self)
     nm_ref_string_unref(mutable->nis_domain);
     nm_ref_string_unref(mutable->proxy_pac_url);
     nm_ref_string_unref(mutable->proxy_pac_script);
+    nm_ref_string_unref(mutable->network_id);
 
     nm_g_slice_free(mutable);
 }
@@ -1925,6 +1931,22 @@ nm_l3_config_data_set_ip6_token(NML3ConfigData *self, NMUtilsIPv6IfaceId ipv6_to
     return TRUE;
 }
 
+const char *
+nm_l3_config_data_get_network_id(const NML3ConfigData *self)
+{
+    nm_assert(_NM_IS_L3_CONFIG_DATA(self, TRUE));
+
+    return nm_ref_string_get_str(self->network_id);
+}
+
+gboolean
+nm_l3_config_data_set_network_id(NML3ConfigData *self, const char *value)
+{
+    nm_assert(_NM_IS_L3_CONFIG_DATA(self, FALSE));
+
+    return nm_ref_string_reset_str(&self->network_id, value);
+}
+
 NMMptcpFlags
 nm_l3_config_data_get_mptcp_flags(const NML3ConfigData *self)
 {
@@ -2451,6 +2473,7 @@ nm_l3_config_data_cmp_full(const NML3ConfigData *a,
     if (NM_FLAGS_HAS(flags, NM_L3_CONFIG_CMP_FLAGS_OTHER)) {
         NM_CMP_DIRECT(a->flags, b->flags);
         NM_CMP_DIRECT(a->ip6_token.id, b->ip6_token.id);
+        NM_CMP_DIRECT_REF_STRING(a->network_id, b->network_id);
         NM_CMP_DIRECT(a->mtu, b->mtu);
         NM_CMP_DIRECT(a->ip6_mtu, b->ip6_mtu);
         NM_CMP_DIRECT_UNSAFE(a->metered, b->metered);
@@ -3464,6 +3487,9 @@ nm_l3_config_data_merge(NML3ConfigData       *self,
     if (self->ip6_token.id == 0)
         self->ip6_token.id = src->ip6_token.id;
 
+    if (!self->network_id)
+        self->network_id = nm_ref_string_ref(src->network_id);
+
     self->metered = NM_MAX((NMTernary) self->metered, (NMTernary) src->metered);
 
     if (self->proxy_method == NM_PROXY_CONFIG_METHOD_UNKNOWN)
diff --git a/src/core/nm-l3-config-data.h b/src/core/nm-l3-config-data.h
index 265e126d89..19c84c5c4a 100644
--- a/src/core/nm-l3-config-data.h
+++ b/src/core/nm-l3-config-data.h
@@ -486,6 +486,10 @@ NMUtilsIPv6IfaceId nm_l3_config_data_get_ip6_token(const NML3ConfigData *self);
 
 gboolean nm_l3_config_data_set_ip6_token(NML3ConfigData *self, NMUtilsIPv6IfaceId ipv6_token);
 
+gboolean nm_l3_config_data_set_network_id(NML3ConfigData *self, const char *network_id);
+
+const char *nm_l3_config_data_get_network_id(const NML3ConfigData *self);
+
 NMMptcpFlags nm_l3_config_data_get_mptcp_flags(const NML3ConfigData *self);
 
 gboolean nm_l3_config_data_set_mptcp_flags(NML3ConfigData *self, NMMptcpFlags mptcp_flags);