diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 892665fcccc..b041126c2ff 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,10 @@
+1999-07-02  Warren Levy  <warrenl@cygnus.com>
+
+	* java/net/PlainDatagramSocketImpl.java (ttl): Removed.
+	* java/net/natPlainDatagramSocketImpl.cc (setTimeToLive): Implemented.
+	(getTimeToLive): Implemented.
+	(setOption): Implemented IP_MULTICAST_IF.
+
 1999-07-01  Bryce McKinlay  <bryce@albatross.co.nz>
 
 	* java/lang/String.java (toString): Check for this == null and throw
diff --git a/libjava/java/net/PlainDatagramSocketImpl.java b/libjava/java/net/PlainDatagramSocketImpl.java
index 541f00a10d8..c65809129ba 100644
--- a/libjava/java/net/PlainDatagramSocketImpl.java
+++ b/libjava/java/net/PlainDatagramSocketImpl.java
@@ -43,10 +43,8 @@ class PlainDatagramSocketImpl extends DatagramSocketImpl
   // localAddress cache  
   InetAddress localAddress;
 
-  // These values are set/read by setOption/getOption.
+  // 'timeout' is set/read by setOption/getOption.
   int timeout = 0;
-  /* InetAddress iface = null; */
-  int ttl = -1;
 
   // FIXME: Probably should have bind (and create?) calls from DatagramSocket
   // constuctor.  If so, then same change should be made to the corresponding
diff --git a/libjava/java/net/natPlainDatagramSocketImpl.cc b/libjava/java/net/natPlainDatagramSocketImpl.cc
index 68259509f10..29a236c8fa8 100644
--- a/libjava/java/net/natPlainDatagramSocketImpl.cc
+++ b/libjava/java/net/natPlainDatagramSocketImpl.cc
@@ -51,6 +51,14 @@ union McastReq
 #endif
 };
 
+union InAddr
+{
+  struct in_addr addr;
+#ifdef HAVE_INET6
+  struct in6_addr addr6;
+#endif
+};
+
 
 // FIXME: routines here and/or in natPlainSocketImpl.cc could throw
 // NoRouteToHostException; also consider UnknownHostException, ConnectException.
@@ -268,17 +276,31 @@ java::net::PlainDatagramSocketImpl::receive (java::net::DatagramPacket *p)
 void
 java::net::PlainDatagramSocketImpl::setTimeToLive (jint ttl)
 {
-  this->ttl = ttl;
-  // throws IOException;
-  // FIXME: TODO - PlainDatagramSocketImpl::setTimeToLive
+  // Assumes IPPROTO_IP rather than IPPROTO_IPV6 since socket created is IPv4.
+  char val = (char) ttl;
+  socklen_t val_len = sizeof(val);
+  if (::setsockopt (fnum, IPPROTO_IP, IP_MULTICAST_TTL, &val, val_len) == 0)
+    return;
+
+  char msg[100];
+  char* strerr = strerror (errno);
+  sprintf (msg, "DatagramSocketImpl.setTimeToLime: %.*s", 80, strerr);
+  JvThrow (new java::io::IOException (JvNewStringUTF (msg)));
 }
 
 jint
 java::net::PlainDatagramSocketImpl::getTimeToLive ()
 {
-  // throws IOException;
-  // FIXME: TODO - PlainDatagramSocketImpl::getTimeToLive
-  return ttl;
+  // Assumes IPPROTO_IP rather than IPPROTO_IPV6 since socket created is IPv4.
+  char val;
+  socklen_t val_len = sizeof(val);
+  if (::getsockopt (fnum, IPPROTO_IP, IP_MULTICAST_TTL, &val, &val_len) == 0)
+    return ((int) val) & 0xFF;
+
+  char msg[100];
+  char* strerr = strerror (errno);
+  sprintf (msg, "DatagramSocketImpl.setTimeToLime: %.*s", 80, strerr);
+  JvThrow (new java::io::IOException (JvNewStringUTF (msg)));
 }
 
 void
@@ -385,9 +407,38 @@ java::net::PlainDatagramSocketImpl::setOption (jint optID,
           JvNewStringUTF ("SO_BINDADDR: read only option")));
         return;
       case _Jv_IP_MULTICAST_IF_ :
-	// FIXME: TODO - Implement IP_MULTICAST_IF.
-        JvThrow (new java::lang::InternalError (
-          JvNewStringUTF ("IP_MULTICAST_IF: option not implemented")));
+	union InAddr u;
+        jbyteArray haddress;
+	jbyte *bytes;
+	int len;
+	int level, opname;
+	const char *ptr;
+
+	haddress = ((java::net::InetAddress *) value)->address;
+	bytes = elements (haddress);
+	len = haddress->length;
+	if (len == 4)
+	  {
+	    level = IPPROTO_IP;
+	    opname = IP_MULTICAST_IF;
+	    memcpy (&u.addr, bytes, len);
+	    len = sizeof (struct in_addr);
+	    ptr = (const char *) &u.addr;
+	  }
+#ifdef HAVE_INET6
+	else if (len == 16)
+	  {
+	    level = IPPROTO_IPV6;
+	    opname = IPV6_MULTICAST_IF;
+	    memcpy (&u.addr6, bytes, len);
+	    len = sizeof (struct in_addr6);
+	    ptr = (const char *) &u.addr6;
+	  }
+#endif
+	else
+	  goto error;
+	if (::setsockopt (fnum, level, opname, ptr, len) != 0)
+	  goto error;
         return;
       case _Jv_SO_TIMEOUT_ :
 	timeout = val;