diff --git a/lib/smux.h b/lib/smux.h
new file mode 100644
index 0000000..91c3d46
--- /dev/null
+++ b/lib/smux.h
@@ -0,0 +1,159 @@
+/* SNMP support
+ * Copyright (C) 1999 Kunihiro Ishiguro <kunihiro@zebra.org>
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra 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, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.  
+ */
+
+#ifndef _ZEBRA_SNMP_H
+#define _ZEBRA_SNMP_H
+
+#define SMUX_PORT_DEFAULT 199
+
+#define SMUXMAXPKTSIZE    1500
+#define SMUXMAXSTRLEN      256
+
+#define SMUX_OPEN       (ASN_APPLICATION | ASN_CONSTRUCTOR | 0)
+#define SMUX_CLOSE      (ASN_APPLICATION | ASN_PRIMITIVE | 1)
+#define SMUX_RREQ       (ASN_APPLICATION | ASN_CONSTRUCTOR | 2)
+#define SMUX_RRSP       (ASN_APPLICATION | ASN_PRIMITIVE | 3)
+#define SMUX_SOUT       (ASN_APPLICATION | ASN_PRIMITIVE | 4)
+
+#define SMUX_GET        (ASN_CONTEXT | ASN_CONSTRUCTOR | 0)
+#define SMUX_GETNEXT    (ASN_CONTEXT | ASN_CONSTRUCTOR | 1)
+#define SMUX_GETRSP     (ASN_CONTEXT | ASN_CONSTRUCTOR | 2)
+#define SMUX_SET	(ASN_CONTEXT | ASN_CONSTRUCTOR | 3)
+#define SMUX_TRAP	(ASN_CONTEXT | ASN_CONSTRUCTOR | 4)
+
+#define SMUX_MAX_FAILURE 3
+
+/* Structures here are mostly compatible with UCD SNMP 4.1.1 */
+#define MATCH_FAILED     (-1)
+#define MATCH_SUCCEEDED  0
+
+/* SYNTAX TruthValue from SNMPv2-TC. */
+#define SNMP_TRUE  1
+#define SNMP_FALSE 2
+
+/* SYNTAX RowStatus from SNMPv2-TC. */
+#define SNMP_VALID  1
+#define SNMP_INVALID 2
+
+#define IN_ADDR_SIZE sizeof(struct in_addr)
+
+struct variable;
+
+#define REGISTER_MIB(descr, var, vartype, theoid)		\
+    smux_register_mib(descr, (struct variable *)var, sizeof(struct vartype), \
+    sizeof(var)/sizeof(struct vartype),			\
+    theoid, sizeof(theoid)/sizeof(oid))
+
+typedef int (WriteMethod)(int action,
+			  u_char  *var_val,
+			  u_char   var_val_type,
+			  size_t   var_val_len,
+			  u_char  *statP,
+			  oid     *name,
+			  size_t   length,
+			  struct variable *v);
+
+typedef u_char *(FindVarMethod)(struct variable *v,
+				oid     *name,
+				size_t  *length,
+				int      exact,
+				size_t  *var_len,
+				WriteMethod   **write_method);
+
+/* SNMP variable */
+struct variable
+{
+  /* Index of the MIB.*/
+  u_char magic;
+
+  /* Type of variable. */
+  char type;
+
+  /* Access control list. */
+  u_short acl;
+
+  /* Callback function. */
+  FindVarMethod *findVar;
+
+  /* Suffix of the MIB. */
+  u_char namelen;
+  oid name[MAX_OID_LEN];
+};
+
+/* SNMP tree. */
+struct subtree
+{
+  /* Tree's oid. */
+  oid name[MAX_OID_LEN];
+  u_char name_len;
+
+  /* List of the variables. */
+  struct variable *variables;
+
+  /* Length of the variables list. */
+  int variables_num;
+
+  /* Width of the variables list. */
+  int variables_width;
+
+  /* Registered flag. */
+  int registered;
+};
+
+struct trap_object
+{
+  FindVarMethod *findVar;
+  u_char namelen;
+  oid name[MAX_OID_LEN];
+};
+
+/* Declare SMUX return value. */
+#define SNMP_LOCAL_VARIABLES \
+  static int32_t snmp_int_val; \
+  static struct in_addr snmp_in_addr_val;
+
+#define SNMP_INTEGER(V) \
+  ( \
+    *var_len = sizeof (int32_t), \
+    snmp_int_val = V, \
+    (u_char *) &snmp_int_val \
+  )
+
+#define SNMP_IPADDRESS(V) \
+  ( \
+    *var_len = sizeof (struct in_addr), \
+    snmp_in_addr_val = V, \
+    (u_char *) &snmp_in_addr_val \
+  )
+
+void smux_init (oid [], size_t);
+void smux_start (void);
+void smux_register_mib(char *, struct variable *, size_t, int, oid [], size_t);
+int smux_header_generic (struct variable *, oid [], size_t *, int, size_t *, 
+    WriteMethod **);
+int smux_trap (oid *, size_t, oid *, size_t, struct trap_object *, size_t, unsigned int);
+
+int oid_compare (oid *, int, oid *, int);
+void oid2in_addr (oid [], int, struct in_addr *);
+void *oid_copy (void *, void *, size_t);
+void oid_copy_addr (oid [], struct in_addr *, int);
+
+#endif /* _ZEBRA_SNMP_H */