diff --git a/src/libsystemd-network/dhcp6-internal.h b/src/libsystemd-network/dhcp6-internal.h
index 2880bc4770..b0d1216eed 100644
--- a/src/libsystemd-network/dhcp6-internal.h
+++ b/src/libsystemd-network/dhcp6-internal.h
@@ -11,12 +11,14 @@
 #include "sd-event.h"
 
 #include "list.h"
+#include "hashmap.h"
 #include "macro.h"
 #include "sparse-endian.h"
 
 typedef struct sd_dhcp6_option {
         unsigned n_ref;
 
+        uint32_t enterprise_identifier;
         uint16_t option;
         void *data;
         size_t length;
@@ -99,6 +101,7 @@ int dhcp6_option_append_pd(uint8_t *buf, size_t len, const DHCP6IA *pd, DHCP6Add
 int dhcp6_option_append_fqdn(uint8_t **buf, size_t *buflen, const char *fqdn);
 int dhcp6_option_append_user_class(uint8_t **buf, size_t *buflen, char **user_class);
 int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *buflen, char **user_class);
+int dhcp6_option_append_vendor_option(uint8_t **buf, size_t *buflen, OrderedHashmap *vendor_options);
 int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode,
                        size_t *optlen, uint8_t **optvalue);
 int dhcp6_option_parse_status(DHCP6Option *option, size_t len);
diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index f763474e6e..fa43587686 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -79,6 +79,39 @@ int dhcp6_option_append(uint8_t **buf, size_t *buflen, uint16_t code,
         return 0;
 }
 
+int dhcp6_option_append_vendor_option(uint8_t **buf, size_t *buflen, OrderedHashmap *vendor_options) {
+        sd_dhcp6_option *options;
+        Iterator i;
+        int r;
+
+        assert(buf);
+        assert(*buf);
+        assert(buflen);
+        assert(vendor_options);
+
+        ORDERED_HASHMAP_FOREACH(options, vendor_options, i) {
+                _cleanup_free_ uint8_t *p = NULL;
+                size_t total;
+
+                total = 4 + 2 + 2 + options->length;
+
+                p = malloc(total);
+                if (!p)
+                        return -ENOMEM;
+
+                unaligned_write_be32(p, options->enterprise_identifier);
+                unaligned_write_be16(p + 4, options->option);
+                unaligned_write_be16(p + 6, options->length);
+                memcpy(p + 8, options->data, options->length);
+
+                r = dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_VENDOR_OPTS, total, p);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
 int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, const DHCP6IA *ia) {
         uint16_t len;
         uint8_t *ia_hdr;
@@ -683,7 +716,7 @@ static sd_dhcp6_option* dhcp6_option_free(sd_dhcp6_option *i) {
         return mfree(i);
 }
 
-int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, sd_dhcp6_option **ret) {
+int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, uint32_t enterprise_identifier, sd_dhcp6_option **ret) {
         assert_return(ret, -EINVAL);
         assert_return(length == 0 || data, -EINVAL);
 
@@ -698,6 +731,7 @@ int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, sd_dhc
         *p = (sd_dhcp6_option) {
                 .n_ref = 1,
                 .option = option,
+                .enterprise_identifier = enterprise_identifier,
                 .length = length,
                 .data = TAKE_PTR(q),
         };
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 76a16a18c1..8d13aef4e7 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -81,6 +81,7 @@ struct sd_dhcp6_client {
         usec_t information_request_time_usec;
         usec_t information_refresh_time_usec;
         OrderedHashmap *extra_options;
+        OrderedHashmap *vendor_options;
 };
 
 static const uint16_t default_req_opts[] = {
@@ -225,6 +226,25 @@ int sd_dhcp6_client_set_prefix_delegation_hint(
         return 0;
 }
 
+int sd_dhcp6_client_add_vendor_option(sd_dhcp6_client *client, sd_dhcp6_option *v) {
+        int r;
+
+        assert_return(client, -EINVAL);
+        assert_return(v, -EINVAL);
+
+        r = ordered_hashmap_ensure_allocated(&client->vendor_options, &dhcp6_option_hash_ops);
+        if (r < 0)
+                return r;
+
+        r = ordered_hashmap_put(client->vendor_options, v, v);
+        if (r < 0)
+                return r;
+
+        sd_dhcp6_option_ref(v);
+
+        return 1;
+}
+
 static int client_ensure_duid(sd_dhcp6_client *client) {
         if (client->duid_len != 0)
                 return 0;
@@ -622,6 +642,13 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (!ordered_hashmap_isempty(client->vendor_options)) {
+                        r = dhcp6_option_append_vendor_option(&opt, &optlen,
+                                                       client->vendor_options);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->ia_pd, &client->hint_pd_prefix);
                         if (r < 0)
@@ -680,6 +707,12 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (!ordered_hashmap_isempty(client->vendor_options)) {
+                        r = dhcp6_option_append_vendor_option(&opt, &optlen, client->vendor_options);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd, NULL);
                         if (r < 0)
@@ -726,6 +759,12 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (!ordered_hashmap_isempty(client->vendor_options)) {
+                        r = dhcp6_option_append_vendor_option(&opt, &optlen, client->vendor_options);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd, NULL);
                         if (r < 0)
diff --git a/src/systemd/meson.build b/src/systemd/meson.build
index 63d0829b67..62baf7784e 100644
--- a/src/systemd/meson.build
+++ b/src/systemd/meson.build
@@ -24,6 +24,7 @@ _not_installed_headers = '''
         sd-dhcp-client.h
         sd-dhcp-lease.h
         sd-dhcp-option.h
+        sd-dhcp6-option.h
         sd-dhcp-server.h
         sd-ipv4acd.h
         sd-ipv4ll.h
diff --git a/src/systemd/sd-dhcp6-client.h b/src/systemd/sd-dhcp6-client.h
index c342be4b29..58a17a5a3f 100644
--- a/src/systemd/sd-dhcp6-client.h
+++ b/src/systemd/sd-dhcp6-client.h
@@ -143,7 +143,10 @@ int sd_dhcp6_client_get_address_request(sd_dhcp6_client *client,
                                         int *request);
 int sd_dhcp6_client_set_address_request(sd_dhcp6_client *client,
                                         int request);
-int sd_dhcp6_client_set_transaction_id(sd_dhcp6_client *client, uint32_t transaction_id);
+int sd_dhcp6_client_set_transaction_id(sd_dhcp6_client *client,
+                                       uint32_t transaction_id);
+int sd_dhcp6_client_add_vendor_option(sd_dhcp6_client *client,
+                                      sd_dhcp6_option *v);
 
 int sd_dhcp6_client_get_lease(
                 sd_dhcp6_client *client,
diff --git a/src/systemd/sd-dhcp6-option.h b/src/systemd/sd-dhcp6-option.h
index c0f1c4df08..88a4986315 100644
--- a/src/systemd/sd-dhcp6-option.h
+++ b/src/systemd/sd-dhcp6-option.h
@@ -26,7 +26,7 @@ _SD_BEGIN_DECLARATIONS;
 
 typedef struct sd_dhcp6_option sd_dhcp6_option;
 
-int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, sd_dhcp6_option **ret);
+int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, uint32_t enterprise_identifier, sd_dhcp6_option **ret);
 sd_dhcp6_option *sd_dhcp6_option_ref(sd_dhcp6_option *ra);
 sd_dhcp6_option *sd_dhcp6_option_unref(sd_dhcp6_option *ra);