diff --git a/isisd/isis_dynhn.c b/isisd/isis_dynhn.c
new file mode 100644
index 0000000..9e151d0
--- /dev/null
+++ b/isisd/isis_dynhn.c
@@ -0,0 +1,124 @@
+/*
+ * IS-IS Rout(e)ing protocol - isis_dynhn.c
+ *                             Dynamic hostname cache
+ * Copyright (C) 2001,2002   Sampo Saaristo
+ *                           Tampere University of Technology      
+ *                           Institute of Communications Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public Licenseas 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, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <time.h>
+#include <zebra.h>
+#include <net/ethernet.h>
+
+#include "vty.h"
+#include "linklist.h"
+#include "memory.h"
+#include "log.h"
+#include "stream.h"
+#include "command.h"
+#include "if.h"
+
+#include "isisd/dict.h"
+#include "isisd/isis_constants.h"
+#include "isisd/isis_common.h"
+#include "isisd/isis_flags.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isisd.h"
+#include "isisd/isis_dynhn.h"
+#include "isisd/isis_misc.h"
+#include "isisd/isis_constants.h"
+
+extern struct isis *isis;
+extern struct host host;
+
+struct list *dyn_cache = NULL;
+
+void
+dyn_cache_init (void)
+{
+  dyn_cache = list_new ();
+  
+  return;
+}
+
+struct isis_dynhn *dynhn_find_by_id (u_char * id)
+{
+  struct listnode *node = NULL;
+  struct isis_dynhn *dyn = NULL;
+
+  for (node = listhead (dyn_cache); node; nextnode (node)) {
+    dyn = getdata (node);
+    if (memcmp (dyn->id, id, ISIS_SYS_ID_LEN) == 0)
+      return dyn;
+  }
+  
+  return NULL;
+}
+
+void
+isis_dynhn_insert (u_char *id, struct hostname *hostname, int level)
+{
+  struct isis_dynhn *dyn;
+
+  dyn = dynhn_find_by_id (id);
+  if (dyn) {
+    memcpy (&dyn->name, hostname, hostname->namelen + 1);
+    memcpy (dyn->id, id, ISIS_SYS_ID_LEN);
+    dyn->refresh = time (NULL);
+    return;
+  }
+  dyn = XMALLOC (MTYPE_ISIS_DYNHN, sizeof (struct isis_dynhn));
+  if (!dyn) {
+    zlog_warn ("isis_dynhn_insert(): out of memory!");
+    return;
+  }
+  memset (dyn,0,sizeof(struct isis_dynhn));
+  /* we also copy the length */
+  memcpy (&dyn->name, hostname, hostname->namelen + 1); 
+  memcpy (dyn->id, id, ISIS_SYS_ID_LEN);
+  dyn->refresh = time (NULL);
+  dyn->level = level;
+  
+  listnode_add (dyn_cache, dyn);
+
+  return;
+}
+
+/*
+ * Level  System ID      Dynamic Hostname  (notag)
+ *  2     0000.0000.0001 foo-gw
+ *  2     0000.0000.0002 bar-gw
+ *      * 0000.0000.0004 this-gw
+ */
+void  dynhn_print_all (struct vty *vty) 
+{
+  struct listnode *node;
+  struct isis_dynhn *dyn;
+
+  vty_out (vty, "Level  System ID      Dynamic Hostname%s", VTY_NEWLINE);
+  for (node = listhead (dyn_cache); node; nextnode (node)) {
+    dyn = getdata (node);
+    vty_out (vty, "%-7d", dyn->level);
+    vty_out (vty, "%-15s%-15s%s", sysid_print (dyn->id), dyn->name.name, 
+	     VTY_NEWLINE);
+  }
+  
+  vty_out (vty,  "     * %s %s%s", sysid_print (isis->sysid), host.name, 
+	   VTY_NEWLINE);
+  return;
+}
+