diff --git a/include/Makefile.am b/include/Makefile.am
index e9a7126..9827950 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -2,7 +2,10 @@
 
 nobase_include_HEADERS = \
 	osmocom/gsupclient/gsup_client.h \
+	osmocom/mslookup/mdns.h \
+	osmocom/mslookup/mdns_sock.h \
 	osmocom/mslookup/mslookup_client_fake.h \
 	osmocom/mslookup/mslookup_client.h \
+	osmocom/mslookup/mslookup_client_mdns.h \
 	osmocom/mslookup/mslookup.h \
 	$(NULL)
diff --git a/include/osmocom/Makefile.am b/include/osmocom/Makefile.am
index dbc2344..b75c86a 100644
--- a/include/osmocom/Makefile.am
+++ b/include/osmocom/Makefile.am
@@ -1,3 +1,4 @@
 SUBDIRS = \
 	hlr \
+	mslookup \
 	$(NULL)
diff --git a/include/osmocom/mslookup/Makefile.am b/include/osmocom/mslookup/Makefile.am
new file mode 100644
index 0000000..72ccd94
--- /dev/null
+++ b/include/osmocom/mslookup/Makefile.am
@@ -0,0 +1,6 @@
+# most headers here are installed, see /include/Makefile.am
+
+noinst_HEADERS = \
+	mdns_msg.h \
+	mdns_rfc.h \
+	$(NULL)
diff --git a/include/osmocom/mslookup/mdns.h b/include/osmocom/mslookup/mdns.h
new file mode 100644
index 0000000..b62e95f
--- /dev/null
+++ b/include/osmocom/mslookup/mdns.h
@@ -0,0 +1,39 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*! \file mdns.h */
+
+#pragma once
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/mslookup/mslookup.h>
+
+#define OSMO_MDNS_DOMAIN_SUFFIX_DEFAULT "mdns.osmocom.org"
+
+struct msgb *osmo_mdns_query_encode(void *ctx, uint16_t packet_id, const struct osmo_mslookup_query *query,
+				    const char *domain_suffix);
+
+struct osmo_mslookup_query *osmo_mdns_query_decode(void *ctx, const uint8_t *data, size_t data_len,
+						   uint16_t *packet_id, const char *domain_suffix);
+
+struct msgb *osmo_mdns_result_encode(void *ctx, uint16_t packet_id, const struct osmo_mslookup_query *query,
+				     const struct osmo_mslookup_result *result, const char *domain_suffix);
+
+int osmo_mdns_result_decode(void *ctx, const uint8_t *data, size_t data_len, uint16_t *packet_id,
+			    struct osmo_mslookup_query *query, struct osmo_mslookup_result *result,
+			    const char *domain_suffix);
diff --git a/include/osmocom/mslookup/mdns_msg.h b/include/osmocom/mslookup/mdns_msg.h
new file mode 100644
index 0000000..ae7dd17
--- /dev/null
+++ b/include/osmocom/mslookup/mdns_msg.h
@@ -0,0 +1,54 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include "mdns_rfc.h"
+
+struct osmo_mdns_record {
+	struct llist_head list;
+	enum osmo_mdns_rfc_record_type type;
+	uint16_t length;
+	uint8_t *data;
+};
+
+struct osmo_mdns_msg_request {
+	uint16_t id;
+	char *domain;
+	enum osmo_mdns_rfc_record_type type;
+};
+
+struct osmo_mdns_msg_answer {
+	uint16_t id;
+	char *domain;
+	/*! list of osmo_mdns_record. */
+	struct llist_head records;
+};
+
+int osmo_mdns_msg_request_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_msg_request *req);
+struct osmo_mdns_msg_request *osmo_mdns_msg_request_decode(void *ctx, const uint8_t *data, size_t data_len);
+
+void osmo_mdns_msg_answer_init(struct osmo_mdns_msg_answer *answer);
+int osmo_mdns_msg_answer_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_msg_answer *ans);
+struct osmo_mdns_msg_answer *osmo_mdns_msg_answer_decode(void *ctx, const uint8_t *data, size_t data_len);
+int osmo_mdns_result_from_answer(struct osmo_mslookup_result *result, const struct osmo_mdns_msg_answer *ans);
+
+struct osmo_mdns_record *osmo_mdns_record_txt_keyval_encode(void *ctx, const char *key, const char *value_fmt, ...);
+int osmo_mdns_record_txt_keyval_decode(const struct osmo_mdns_record *rec,
+				       char *key_buf, size_t key_size, char *value_buf, size_t value_size);
diff --git a/include/osmocom/mslookup/mdns_rfc.h b/include/osmocom/mslookup/mdns_rfc.h
new file mode 100644
index 0000000..9d6be5a
--- /dev/null
+++ b/include/osmocom/mslookup/mdns_rfc.h
@@ -0,0 +1,113 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/endian.h>
+#include <osmocom/mslookup/mdns.h>
+
+/* RFC 1035 2.3.4 */
+#define OSMO_MDNS_RFC_MAX_NAME_LEN 255
+
+/* RFC 1035 3.3 <character-string> */
+#define OSMO_MDNS_RFC_MAX_CHARACTER_STRING_LEN 256
+
+enum osmo_mdns_rfc_record_type {
+	OSMO_MDNS_RFC_RECORD_TYPE_UNKNOWN = 0,
+
+	/* RFC 1035 3.2.2 */
+	OSMO_MDNS_RFC_RECORD_TYPE_A = 1, /* IPv4 address */
+	OSMO_MDNS_RFC_RECORD_TYPE_TXT = 16, /* Text strings */
+
+	/* RFC 3596 2.1 */
+	OSMO_MDNS_RFC_RECORD_TYPE_AAAA = 28, /* IPv6 address */
+
+	/* RFC 1035 3.2.3 */
+	OSMO_MDNS_RFC_RECORD_TYPE_ALL = 255, /* Request only: ask for all */
+};
+
+enum osmo_mdns_rfc_class {
+	OSMO_MDNS_RFC_CLASS_UNKNOWN = 0,
+
+	/* RFC 1035 3.2.4 */
+	OSMO_MDNS_RFC_CLASS_IN = 1, /* Internet and IP networks */
+
+	/* RFC 1035 3.2.5 */
+	OSMO_MDNS_RFC_CLASS_ALL = 255, /* Request only: ask for all */
+};
+
+/* RFC 1035 4.1.1 */
+struct osmo_mdns_rfc_header {
+#if OSMO_IS_LITTLE_ENDIAN
+	uint16_t id;
+	uint8_t rd:1,
+		tc:1,
+		aa:1,
+		opcode:4,
+		qr:1; /* QR (0: query, 1: response) */
+	uint8_t rcode:4,
+		z:3,
+		ra:1;
+	uint16_t qdcount; /* Number of questions */
+	uint16_t ancount; /* Number of answers */
+	uint16_t nscount; /* Number of authority records */
+	uint16_t arcount; /* Number of additional records */
+#elif OSMO_IS_BIG_ENDIAN
+/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianess.py) */
+	uint16_t id;
+	uint8_t qr:1, opcode:4, aa:1, tc:1, rd:1;
+	uint8_t ra:1, z:3, rcode:4;
+	uint16_t qdcount;
+	uint16_t ancount;
+	uint16_t nscount;
+	uint16_t arcount;
+#endif
+} __attribute__ ((packed));
+
+/* RFC 1035 4.1.2 */
+struct osmo_mdns_rfc_question {
+	char *domain; /* Domain to be encoded as qname (e.g. "gsup.hlr.1234567.imsi") */
+	enum osmo_mdns_rfc_record_type qtype;
+	enum osmo_mdns_rfc_class qclass;
+};
+
+/* RFC 1035 4.1.3 */
+struct osmo_mdns_rfc_record {
+	char *domain; /* Domain to be encoded as name (e.g. "gsup.hlr.1234567.imsi") */
+	enum osmo_mdns_rfc_record_type type;
+	enum osmo_mdns_rfc_class class;
+	uint32_t ttl;
+	uint16_t rdlength;
+	uint8_t *rdata;
+};
+
+char *osmo_mdns_rfc_qname_encode(void *ctx, const char *domain);
+char *osmo_mdns_rfc_qname_decode(void *ctx, const char *qname, size_t qname_len);
+
+void osmo_mdns_rfc_header_encode(struct msgb *msg, const struct osmo_mdns_rfc_header *hdr);
+int osmo_mdns_rfc_header_decode(const uint8_t *data, size_t data_len, struct osmo_mdns_rfc_header *hdr);
+
+int osmo_mdns_rfc_question_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_rfc_question *qst);
+struct osmo_mdns_rfc_question *osmo_mdns_rfc_question_decode(void *ctx, const uint8_t *data, size_t data_len);
+
+int osmo_mdns_rfc_record_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_rfc_record *rec);
+struct osmo_mdns_rfc_record *osmo_mdns_rfc_record_decode(void *ctx, const uint8_t *data, size_t data_len,
+							 size_t *record_len);
diff --git a/include/osmocom/mslookup/mdns_sock.h b/include/osmocom/mslookup/mdns_sock.h
new file mode 100644
index 0000000..615e971
--- /dev/null
+++ b/include/osmocom/mslookup/mdns_sock.h
@@ -0,0 +1,33 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <netdb.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+
+struct osmo_mdns_sock {
+	struct osmo_fd osmo_fd;
+	struct addrinfo *ai;
+};
+
+struct osmo_mdns_sock *osmo_mdns_sock_init(void *ctx, const char *ip, unsigned int port,
+					   int (*cb)(struct osmo_fd *fd, unsigned int what),
+					   void *data, unsigned int priv_nr);
+int osmo_mdns_sock_send(const struct osmo_mdns_sock *mdns_sock, struct msgb *msg);
+void osmo_mdns_sock_cleanup(struct osmo_mdns_sock *mdns_sock);
diff --git a/include/osmocom/mslookup/mslookup_client_mdns.h b/include/osmocom/mslookup/mslookup_client_mdns.h
new file mode 100644
index 0000000..e699107
--- /dev/null
+++ b/include/osmocom/mslookup/mslookup_client_mdns.h
@@ -0,0 +1,38 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+struct osmo_mslookup_client;
+struct osmo_mslookup_client_method;
+
+/*! MS Lookup mDNS server bind default IP. Taken from the Administratevly Scoped block, particularly the Organizational
+ * Scoped range, https://tools.ietf.org/html/rfc2365 . */
+#define OSMO_MSLOOKUP_MDNS_IP4 "239.192.23.42"
+#define OSMO_MSLOOKUP_MDNS_IP6 "ff08::23:42" // <-- TODO: sane?
+#define OSMO_MSLOOKUP_MDNS_PORT 4266
+
+struct osmo_mslookup_client_method *osmo_mslookup_client_add_mdns(struct osmo_mslookup_client *client, const char *ip,
+								  uint16_t port, int initial_packet_id,
+								  const char *domain_suffix);
+
+const struct osmo_sockaddr_str *osmo_mslookup_client_method_mdns_get_bind_addr(struct osmo_mslookup_client_method *dns_method);
+
+const char *osmo_mslookup_client_method_mdns_get_domain_suffix(struct osmo_mslookup_client_method *dns_method);