diff -X exclude_files -Nabur ospfd2.1/linux/linux.C ospfd2.2/linux/linux.C
--- ospfd2.1/linux/linux.C	Thu Apr 19 17:50:48 2001
+++ ospfd2.2/linux/linux.C	Mon May 14 14:27:10 2001
@@ -90,6 +90,20 @@
     }
 }
 
+/* Cloase all monitor connections. Necessary when, for example,
+ * simulated ospfd restarts but its process remains.
+ */
+
+void Linux::close_monitor_connections()
+
+{
+    AVLsearch iter(&monfds);
+    TcpConn *conn;
+
+    while ((conn = (TcpConn *)iter.next()))
+        close_monitor_connection(conn);
+}
+
 void Linux::process_mon_io(fd_set *fdsetp, fd_set *wrsetp)
 
 {
@@ -123,7 +137,7 @@
      fd = conn->monfd();
      if ((nbytes = conn->monpkt.receive((void **)&msg, type, subtype)) < 0)
 	  close_monitor_connection(conn);
-     else if (type != 0)
+     else if (type != 0 && ospf)
 	  ospf->monitor((MonMsg *)msg, type, nbytes, fd);
 }
 
@@ -157,6 +171,7 @@
 {
     close(conn->monfd());
     monfds.remove(conn);
+    if (ospf)
     ospf->register_for_opqs(conn->monfd(), true);
     delete conn;
 }
diff -X exclude_files -Nabur ospfd2.1/linux/linux.h ospfd2.2/linux/linux.h
--- ospfd2.1/linux/linux.h	Thu Apr 19 17:50:48 2001
+++ ospfd2.2/linux/linux.h	Mon May 14 14:27:10 2001
@@ -37,6 +37,7 @@
     void process_monitor_request(class TcpConn *);
     void accept_monitor_connection();
     void close_monitor_connection(class TcpConn *);
+    void close_monitor_connections();
     void monitor_listen();
 };
 
diff -X exclude_files -Nabur ospfd2.1/linux/ospfd_linux.C ospfd2.2/linux/ospfd_linux.C
--- ospfd2.1/linux/ospfd_linux.C	Thu Apr 19 17:50:48 2001
+++ ospfd2.2/linux/ospfd_linux.C	Mon May 14 14:27:10 2001
@@ -267,7 +267,8 @@
         syslog(LOG_ERR, "rtnetlink recvfrom: %m");
 	return;
     }
-    msg = (nlmsghdr *)buffer;
+    for (msg = (nlmsghdr *)buffer; NLMSG_OK(msg, (uns32)plen);
+	 msg = NLMSG_NEXT(msg, plen)) {
     switch (msg->nlmsg_type) {
         in_addr in;
 	ifinfomsg *ifinfo;
@@ -277,6 +278,7 @@
 	rtmsg *rtm;
 	InAddr net;
 	InMask mask;
+	    nlmsgerr *errmsg;
       case RTM_NEWLINK:	// Interface flags change
 	ifinfo = (ifinfomsg *)NLMSG_DATA(msg);
 	syslog(LOG_NOTICE, "Ifc change IfIndex %d flags 0x%x",
@@ -307,6 +309,7 @@
 	syslog(LOG_NOTICE, "Interface addr change %s", inet_ntoa(in));
 	read_config();
 	break;
+          case RTM_NEWROUTE:
       case RTM_DELROUTE:
 	rtm = (rtmsg *)NLMSG_DATA(msg);
 	if (rtm->rtm_protocol != PROT_OSPF)
@@ -328,12 +331,27 @@
 	    mask = ~((1 << (32-rtm->rtm_dst_len)) - 1);
 	    net = ntoh32(in.s_addr) & mask;
 	}
+	    if (msg->nlmsg_type == RTM_DELROUTE) {
 	syslog(LOG_NOTICE, "Krt Delete %s", inet_ntoa(in));
 	ospf->krt_delete_notification(net, mask);
+	    }
+	    else if (dumping_remnants)
+	        ospf->remnant_notification(net, mask);
+	    break;
+	  case NLMSG_DONE:
+	    dumping_remnants = false;
+	    break;
+          case NLMSG_OVERRUN:
+	    syslog(LOG_ERR, "Overrun on routing socket: %m");
+	    break;
+	  case NLMSG_ERROR:
+	    errmsg = (nlmsgerr *)NLMSG_DATA(msg);
+	    syslog(LOG_ERR, "Netlink error %d", errmsg->error);
 	break;
       default:
 	break;
     }
+    }
 }
 #else
 void LinuxOspfd::netlink_receive(int)
@@ -394,6 +412,7 @@
     (void) gettimeofday(&last_time, NULL);
     changing_routerid = false;
     change_complete = false;
+    dumping_remnants = false;
     // Allow core files
     rlim.rlim_max = RLIM_INFINITY;
     (void) setrlimit(RLIMIT_CORE, &rlim);
diff -X exclude_files -Nabur ospfd2.1/linux/ospfd_linux.h ospfd2.2/linux/ospfd_linux.h
--- ospfd2.1/linux/ospfd_linux.h	Thu Apr 19 17:50:48 2001
+++ ospfd2.2/linux/ospfd_linux.h	Mon May 14 14:27:11 2001
@@ -38,6 +38,7 @@
     FILE *logstr;
     bool changing_routerid;
     bool change_complete;
+    bool dumping_remnants;
   public:
     LinuxOspfd();
     ~LinuxOspfd();
@@ -57,6 +58,7 @@
     void rtdel(InAddr, InMask, MPath *ompp);
     void add_mcache(InAddr src, InAddr group, MCache *);
     void del_mcache(InAddr src, InAddr group);
+    void upload_remnants();
     char *phyname(int phyint);
     void sys_spflog(int msgno, char *msgbuf);
     void halt(int code, char *string);
diff -X exclude_files -Nabur ospfd2.1/linux/system.C ospfd2.2/linux/system.C
--- ospfd2.1/linux/system.C	Thu Apr 19 17:50:48 2001
+++ ospfd2.2/linux/system.C	Mon May 14 14:27:11 2001
@@ -407,6 +407,16 @@
     if (-1 == ioctl(udpfd, SIOCDELRT, (char *)&m))
 	syslog(LOG_ERR, "SIOCDELRT: %m");
 }
+
+/* Uploading remnant routing table entries is not supported
+ * on older Linux versions.
+ */
+
+void LinuxOspfd::upload_remnants()
+
+{
+}
+
 #else
 /* On Linux 2.2, add and delete routing table entries
  * via the rtnetlink interface. Note that we are setting
@@ -553,6 +563,45 @@
     if (-1 == send(rtsock, nlm, size, 0))
 	syslog(LOG_ERR, "del route through routing socket: %m");
 }
+
+/* Request the kernel to upload the current set of routing
+ * table entries that it has.
+ */
+
+void LinuxOspfd::upload_remnants()
+
+{
+    nlmsghdr *nlm;
+    rtmsg *rtm;
+    int size;
+
+    // Set state to dumping
+    dumping_remnants = true;
+
+    // Calculate size of netlink message
+    size = NLMSG_SPACE(sizeof(*rtm)); // Only a routing message
+    // Allocate netlink message
+    nlm = (nlmsghdr *) new char[size];
+    nlm->nlmsg_len = size;
+    nlm->nlmsg_type = RTM_GETROUTE;
+    nlm->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+    nlm->nlmsg_seq = nlm_seq++;
+    nlm->nlmsg_pid = 0;
+    rtm = (rtmsg *) NLMSG_DATA(nlm);
+    rtm->rtm_family = AF_INET;
+    rtm->rtm_dst_len = 0;
+    rtm->rtm_src_len = 0;
+    rtm->rtm_table = 0;
+    rtm->rtm_protocol = PROT_OSPF;
+    rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+    rtm->rtm_type = RTN_UNICAST;
+    rtm->rtm_flags = 0;
+
+    // Send to routing socket
+    if (-1 == send(rtsock, nlm, size, 0))
+	syslog(LOG_ERR, "routing table dump: %m");
+}
+
 #endif
 
 /* Add a multicast routing table entry to the kernel.
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/ospf_sim.tcl ospfd2.2/ospf_sim/ospf_sim.tcl
--- ospfd2.1/ospf_sim/ospf_sim.tcl	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/ospf_sim.tcl	Mon May 14 14:27:15 2001
@@ -1514,9 +1514,11 @@
 .mbar.add add command -label "Virtual Link" -command "AddVL"
 .mbar.add add command -label "Static Route" -command [list SelectRouter add_static_menu]
 menu .mbar.toggle -tearoff 0
-.mbar add cascade -label "Toggle" -underline 0 -menu .mbar.toggle
-.mbar.toggle add command -label "Router" -command [list SelectRouter togglertr]
-.mbar.toggle add command -label "Interface" -command "ToggleInterface"
+.mbar add cascade -label "Router" -underline 0 -menu .mbar.toggle
+.mbar.toggle add command -label "Toggle" -command [list SelectRouter togglertr]
+.mbar.toggle add command -label "Restart" -command [list SelectRouter rstrtr]
+.mbar.toggle add command -label "Hitless Restart" -command [list SelectRouter hitlessrtr]
+.mbar.toggle add command -label "Toggle Interface" -command "ToggleInterface"
 menu .mbar.sim
 .mbar add cascade -label "Simulation" -underline 0 -menu .mbar.sim
 .mbar.sim add command -label "Resume" -command "time_resume"
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/ospfd_sim.C ospfd2.2/ospf_sim/ospfd_sim.C
--- ospfd2.1/ospf_sim/ospfd_sim.C	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/ospfd_sim.C	Mon May 14 14:27:15 2001
@@ -189,6 +189,11 @@
 {
     InPkt *pkt;
     InAddr daddr;
+    SimRte *rte;
+
+    // Discard packet if OSPF not ready
+    if (!ospf)
+        return;
 
     pkt = (InPkt *) (pkthdr+1);
     daddr = ntoh32(pkt->i_dest);
@@ -196,8 +201,7 @@
     if (!IN_CLASSD(daddr)) {
 	InAddr home;
         if ((!get_port_addr(daddr, home)) || (home != ospf->my_id())) {
-	    MPath *mpp;
-	    if ((mpp = ospf->ip_lookup(daddr)) == 0) {
+	    if (!(rte = rttbl.best_match(daddr))) {
 	        sendicmp(ICMP_TYPE_UNREACH, ICMP_CODE_UNREACH_HOST,
 			 0, 0, pkt, 0, 0, 0);
 	    }
@@ -208,10 +212,10 @@
 	    }
 	    else {
 	        InAddr gw;
-		gw = mpp->NHs[0].gw;
-		if (gw != 0 && mpp->NHs[0].if_addr == 0)
+		gw = rte->gw;
+		if (gw != 0 && rte->if_addr == 0)
 		    gw = (InAddr) -1;
-	        sendpkt(pkt, mpp->NHs[0].phyint, gw);
+	        sendpkt(pkt, rte->phyint, gw);
 	    }
 	}
 	else
@@ -497,6 +501,14 @@
 	    mtraces.add(mtrace);
 	    mtrace->send_query();
 	    break;
+ 	  case SIM_RESTART:
+	    close_monitor_connections();
+	    delete ospf;
+	    ospf = 0;
+	    // Will then get First tick, and config
+	    break;
+ 	  case SIM_RESTART_HITLESS:
+	    break;
 	  default:
 	    break;
       }
@@ -961,4 +973,85 @@
     else
         simsys->sendpkt(iphdr);
     delete [] ((byte *) iphdr);
+}
+
+/* The follow two routines taken from ospfd's INtbl
+ * and INrte classes.
+ * Should make these utility routines.
+ */
+
+/* Add an entry to an IP routing table entry. Install the
+ * prefix pointers so that the best match operations will
+ * work correctly.
+ */
+
+SimRte *SimRttbl::add(uns32 net, uns32 mask)
+
+{
+    SimRte *rte;
+    SimRte *parent;
+    SimRte *child;
+    AVLsearch iter(&routes);
+
+    if ((rte = (SimRte *) routes.find(net, mask)))
+	return(rte);
+    // Add to routing table entry
+    rte = new SimRte(net, mask);
+    routes.add(rte);
+    // Set prefix pointer
+    parent = (SimRte *) routes.previous(net, mask);
+    for (; parent; parent = parent->prefix) {
+	if (rte->is_child(parent)) {
+	    rte->prefix = parent;
+	    break;
+	}
+    }
+    // Set children's parent pointers
+    iter.seek(rte);
+    while ((child = (SimRte *)iter.next()) && child->is_child(rte)) {
+	if (child->prefix && child->prefix->is_child(rte))
+	    continue;
+	child->prefix = rte;
+    }
+
+    return(rte);
+}
+
+/* Find the best matching routing table entry for a given
+ * IP destination.
+ */
+
+SimRte *SimRttbl::best_match(uns32 addr)
+
+{
+    SimRte *rte;
+    SimRte *prev;
+
+    rte = (SimRte *) routes.root();
+    prev = 0;
+    while (rte) {
+	if (addr < rte->net())
+	    rte = (SimRte *) rte->go_left();
+	else if (addr > rte->net() ||
+		 0xffffffff > rte->mask()) {
+	    prev = rte;
+	    rte = (SimRte *) rte->go_right();
+	}
+	else
+	    // Matching host route
+	    break;
+    }
+
+    // If no exact match, take previous entry
+    if (!rte)
+	rte = prev;
+    // Go up prefix chain, looking for valid routes
+    for (; rte; rte = rte->prefix) {
+	if ((addr & rte->mask()) != rte->net())
+	    continue;
+	if (rte->reachable)
+	    break;
+    }
+
+    return(rte->reject ? 0 : rte);
 }
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/ospfd_sim.h ospfd2.2/ospf_sim/ospfd_sim.h
--- ospfd2.1/ospf_sim/ospfd_sim.h	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/ospfd_sim.h	Mon May 14 14:27:15 2001
@@ -20,6 +20,57 @@
 extern char *LOOPADDR;
 
 class SimPktQ;
+class SimRte;
+
+/* Routing table kept within a simulated OSPF router. We don't
+ * use the simulated ospfd's table, so that we can simulate
+ * hitless restart scenarios.
+ */
+
+class SimRttbl {
+  public:
+    AVLtree routes;
+    SimRte *add(InAddr net, InMask mask);
+    SimRte *best_match(InAddr addr);
+};
+
+class SimRte : public AVLitem {
+  public:
+    SimRte *prefix;
+    bool reachable;
+    bool reject;
+    int phyint;		// Outgoing interface
+    InAddr if_addr;
+    InAddr gw;		// Next hop address
+    
+    inline SimRte(InAddr, InMask);
+    inline InAddr net();
+    inline InAddr mask();
+    inline int is_child(SimRte *o);
+};    
+
+inline SimRte::SimRte(InAddr a, InMask m) : AVLitem(a, m)
+{
+    prefix = 0;
+    reachable = false;
+    reject = false;
+}
+inline InAddr SimRte::net()
+{
+    return(index1());
+}
+inline InAddr SimRte::mask()
+{
+    return(index2());
+}
+inline int SimRte::is_child(SimRte *o)
+{
+    return((net() & o->mask()) == o->net() && mask() >= o->mask());
+}
+
+/* Global class representing a simulated OSPF router. Contains
+ * the implementation of its system interface.
+ */
 
 class SimSys : public Linux {
     int ctl_fd;     // Connection to controller
@@ -30,6 +81,7 @@
     AVLtree address_map; // IP address to group mapping
     AVLtree port_map; // Phyint to file descriptor mapping
     AVLtree membership; // Interface group membership		   
+    SimRttbl rttbl;	// Routing table
     SimPktQ *rcv_head;  // Queued receives
     SimPktQ *rcv_tail;
     SPFtime xmt_stamp; // Transmission timestamp
@@ -56,6 +108,7 @@
     void rtdel(InAddr, InMask, MPath *);
     void add_mcache(InAddr src, InAddr group, MCache *);
     void del_mcache(InAddr src, InAddr group);
+    virtual void upload_remnants();
     char *phyname(int phyint);
     void sys_spflog(int code, char *buffer);
     void halt(int code, char *string);
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/sim.C ospfd2.2/ospf_sim/sim.C
--- ospfd2.1/ospf_sim/sim.C	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/sim.C	Mon May 14 14:27:15 2001
@@ -52,6 +52,8 @@
 
 int StartRouter(ClientData, Tcl_Interp *, int, char *argv[]);
 int ToggleRouter(ClientData, Tcl_Interp *, int, char *argv[]);
+int RestartRouter(ClientData, Tcl_Interp *, int, char *argv[]);
+int HitlessRestart(ClientData, Tcl_Interp *, int, char *argv[]);
 int StartPing(ClientData, Tcl_Interp *, int, char *argv[]);
 int StopPing(ClientData, Tcl_Interp *, int, char *argv[]);
 int StartTraceroute(ClientData, Tcl_Interp *, int, char *argv[]);
@@ -240,6 +242,8 @@
     // Install C-language TCl commands
     Tcl_CreateCommand(interp, "startrtr", StartRouter, 0, 0);
     Tcl_CreateCommand(interp, "togglertr", ToggleRouter, 0, 0);
+    Tcl_CreateCommand(interp, "rstrtr", RestartRouter, 0, 0);
+    Tcl_CreateCommand(interp, "hitlessrtr", HitlessRestart, 0, 0);
     Tcl_CreateCommand(interp, "start_ping", StartPing, 0, 0);
     Tcl_CreateCommand(interp, "stop_ping", StopPing, 0, 0);
     Tcl_CreateCommand(interp, "start_traceroute", StartTraceroute, 0, 0);
@@ -467,30 +471,9 @@
 	switch(type) {
 	    char tcl_command[80];
 	  case SIM_HELLO:
-	    SimNode *newnode;
-	    // Delete temporary router
 	    hello = (SimHello *)msg;
-	    newnode = new SimNode(hello->rtrid, fd);
-	    sim->simnodes.add(newnode);
-	    newnode->home_port = ntoh16(hello->myport);
-	    addr.s_addr = hton32(newnode->id());
-	    newnode->color = SimNode::WHITE;
-	    if (Tcl_VarEval(sim->interp, "color_router ", inet_ntoa(addr),
-			" white", 0) != TCL_OK)
-	        printf("color_router: %s\n", sim->interp->result);
-	    // Initialize its idea of time
-	    TickBody tm;
-	    tm.tick = sim->n_ticks;
-	    newnode->pktdata.queue_xpkt(&tm, SIM_FIRST_TICK, 0, sizeof(tm));
-	    // Send address to port maps
-	    send_addrmap(newnode);
-	    send_addrmap_increment(0, newnode);
-	    // Download node's configuration
-	    if (Tcl_VarEval(sim->interp,"sendcfg ",
-			    inet_ntoa(addr),0) != TCL_OK)
-	        printf("sendcfg: %s\n", sim->interp->result);
-	    // Also frees message space
-	    delete node;
+	    // Start the node, reassigning simnode class
+	    restart_node(node, hello->rtrid, fd, ntoh16(hello->myport));
 	    break;
 	  case SIM_TICK_RESPONSE:
             NodeStats *statentry;
@@ -567,6 +550,43 @@
     }
 }
 
+/* (Re)start a router.
+ */
+
+void SimCtl::restart_node(SimNode *node, InAddr id, int fd, uns16 home_port)
+
+{
+    in_addr addr;
+    TickBody tm;
+    SimNode *newnode;
+
+    newnode = new SimNode(id, fd);
+    sim->simnodes.add(newnode);
+    newnode->home_port = home_port;
+    addr.s_addr = hton32(newnode->id());
+    newnode->color = SimNode::WHITE;
+    if (Tcl_VarEval(sim->interp, "color_router ", inet_ntoa(addr),
+		    " white", 0) != TCL_OK)
+        printf("color_router: %s\n", sim->interp->result);
+    // If the router has already been running, tell it to restart
+    if (node->id() != 0)
+        newnode->pktdata.queue_xpkt(NULL, SIM_RESTART, 0, 0);
+    // Initialize its idea of time
+    tm.tick = sim->n_ticks;
+    newnode->pktdata.queue_xpkt(&tm, SIM_FIRST_TICK, 0, sizeof(tm));
+    // Send address to port maps
+    send_addrmap(newnode);
+    send_addrmap_increment(0, newnode);
+    // Download node's configuration
+    addr.s_addr = hton32(newnode->id());
+    if (Tcl_VarEval(sim->interp,"sendcfg ", inet_ntoa(addr),0) != TCL_OK)
+        printf("sendcfg: %s\n", sim->interp->result);
+
+    // Delete previous router
+    // Also frees message space
+    delete node;
+}
+
 /* Construct a node statistics entry.
  */
 
@@ -725,6 +745,48 @@
         Tcl_VarEval(interp, "startrtr ", argv[1], 0);
     else
         node->pktdata.queue_xpkt(NULL, SIM_SHUTDOWN, 0, 0);
+
+    return(TCL_OK);
+}
+
+/* Restart a simulated router.
+ * If it is not running, simply start it.
+ */
+
+int RestartRouter(ClientData, Tcl_Interp *interp, int, char *argv[])
+
+{
+    InAddr id;
+    SimNode *node;
+
+    id = ntoh32(inet_addr(argv[1]));
+    if (!(node = (SimNode *) sim->simnodes.find(id, 0)))
+        Tcl_VarEval(interp, "startrtr ", argv[1], 0);
+    else {
+	sim->simnodes.remove(node);
+	sim->restart_node(node, node->id(), node->fd, node->home_port);
+    }
+
+    return(TCL_OK);
+}
+
+/* Perform a hitless restart of a simulated router.
+ * If it is not running, simply start it.
+ */
+
+int HitlessRestart(ClientData, Tcl_Interp *interp, int, char *argv[])
+
+{
+    InAddr id;
+    SimNode *node;
+    HitlessRestartMsg m;
+
+    m.period = 60;
+    id = ntoh32(inet_addr(argv[1]));
+    if (!(node = (SimNode *) sim->simnodes.find(id, 0)))
+        Tcl_VarEval(interp, "startrtr ", argv[1], 0);
+    else
+        node->pktdata.queue_xpkt(&m, SIM_RESTART_HITLESS, 0, sizeof(m));
 
     return(TCL_OK);
 }
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/sim.h ospfd2.2/ospf_sim/sim.h
--- ospfd2.1/ospf_sim/sim.h	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/sim.h	Mon May 14 14:27:15 2001
@@ -39,6 +39,8 @@
     SIM_ADD_MEMBER,	// Add membership on segment
     SIM_DEL_MEMBER,	// Delete membership on segment
     SIM_START_MTRACE,	// Start multicast traceroute session
+    SIM_RESTART,	// Restart router
+    SIM_RESTART_HITLESS,// Hitless restart of router
 
     // Responses from ospfds
     SIM_HELLO = 100,	// Initial identification
@@ -91,6 +93,14 @@
     InAddr src;
     InAddr dest;
     byte ttl;
+};
+
+/* Body of the Hitless Restart message contains the length
+ * of the hitless restart period in seconds.
+ */
+
+struct HitlessRestartMsg {
+    uns16 period;
 };
 
 /* Tick responses carry the #LSAs and checksum for 
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/sim_system.C ospfd2.2/ospf_sim/sim_system.C
--- ospfd2.1/ospf_sim/sim_system.C	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/sim_system.C	Mon May 14 14:27:15 2001
@@ -215,22 +215,50 @@
 }
 
 /* Add/modify a kernel routing table entry.
- * NULL for simulator, as we just use the routing table
- * entries internal to the OSPF application.
  */
 
-void SimSys::rtadd(InAddr, InMask, MPath *, MPath *, bool)
+void SimSys::rtadd(InAddr net, InMask mask, MPath *mpp, MPath *, bool reject)
 
 {
+    SimRte *rte;
+    rte = rttbl.add(net, mask);
+    rte->reachable = true;
+    rte->reject = reject;
+    if (mpp) {
+	rte->phyint = mpp->NHs[0].phyint;
+	rte->if_addr = mpp->NHs[0].if_addr;
+	rte->gw = mpp->NHs[0].gw;
+    }
 }
 
 /* Delete a kernel routing table entry.
- * Again, NULL for simulator.
+ * We don't actually delete them, but instead set the
+ * reachability to false - this will cause the lookup to
+ * fall back on a less-specific prefix.
  */
 
-void SimSys::rtdel(InAddr, InMask, MPath *)
+void SimSys::rtdel(InAddr net, InMask mask, MPath *)
 
 {
+    SimRte *rte;
+    rte = rttbl.add(net, mask);
+    rte->reachable = false;
+}
+
+/* Upload the current set of routing
+ * table entries into the OSPF application.
+ */
+
+void SimSys::upload_remnants()
+
+{
+    SimRte *rte;
+    AVLsearch iter(&rttbl.routes);
+
+    while ((rte = (SimRte *)iter.next())) {
+        if (rte->reachable)
+	    ospf->remnant_notification(rte->net(), rte->mask());
+    }
 }
 
 /* Add a multicast routing table entry to the kernel.
diff -X exclude_files -Nabur ospfd2.1/ospf_sim/simctl.h ospfd2.2/ospf_sim/simctl.h
--- ospfd2.1/ospf_sim/simctl.h	Thu Apr 19 17:50:50 2001
+++ ospfd2.2/ospf_sim/simctl.h	Mon May 14 14:27:15 2001
@@ -29,6 +29,7 @@
     void store_mapping(uns32 net_or_addr, uns32 rtr);
     void send_addrmap(class SimNode *);
     void send_addrmap_increment(class IfMap *, class SimNode *);
+    void restart_node(SimNode *, InAddr, int, uns16);
 
     friend class SimNode;
     friend int main(int argc, char *argv[]);
@@ -36,6 +37,8 @@
     friend void tick(ClientData);
     friend int StartRouter(ClientData, Tcl_Interp *, int, char *argv[]);
     friend int ToggleRouter(ClientData, Tcl_Interp *interp, int, char *argv[]);
+    friend int RestartRouter(ClientData,Tcl_Interp *interp, int, char *argv[]);
+    friend int HitlessRestart(ClientData,Tcl_Interp *interp,int, char *argv[]);
     friend int AddMapping(ClientData, Tcl_Interp *interp, int, char *argv[]);
     friend int AddNetMember(ClientData, Tcl_Interp *interp, int, char *argv[]);
     friend int TimeStop(ClientData, Tcl_Interp *, int, char *argv[]);
@@ -106,6 +109,8 @@
     friend int main(int argc, char *argv[]);
     friend void tick(ClientData);
     friend int ToggleRouter(ClientData, Tcl_Interp *interp, int, char *argv[]);
+    friend int RestartRouter(ClientData,Tcl_Interp *interp, int, char *argv[]);
+    friend int HitlessRestart(ClientData,Tcl_Interp *interp,int, char *argv[]);
     friend int SendGeneral(ClientData, Tcl_Interp *, int, char *argv[]);
     friend int SendArea(ClientData, Tcl_Interp *, int, char *argv[]);
     friend int SendInterface(ClientData, Tcl_Interp *, int, char *argv[]);
diff -X exclude_files -Nabur ospfd2.1/src/dbage.C ospfd2.2/src/dbage.C
--- ospfd2.1/src/dbage.C	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/dbage.C	Mon May 14 14:27:10 2001
@@ -130,6 +130,12 @@
     // Process any pending LSA activity (flooding, origination)
     // Synchronize with kernel
     ospf->krt_sync();
+
+    // If not performing a hitless restart, upload remnants
+    if (ospf->need_remnants) {
+        ospf->need_remnants = false;
+	sys->upload_remnants();
+    }
 }
 
 /* Main aging routine called once a second. Increment the current
diff -X exclude_files -Nabur ospfd2.1/src/ospf.C ospfd2.2/src/ospf.C
--- ospfd2.1/src/ospf.C	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/ospf.C	Mon May 14 14:27:10 2001
@@ -106,6 +106,7 @@
     ospf_mtu = 65535;
     full_sched = false;
     ase_sched = false;
+    need_remnants = true;
 
     n_dijkstras = 0;
 
@@ -700,6 +701,25 @@
         KrtSync *item;
 	item = new KrtSync(net, mask);
 	krtdeletes.add(item);
+    }
+}
+
+/* Kernel has indicated that we have previously installed
+ * a route to this destination. If we don't have the destination
+ * currently in our routing table, assume that it is a remnant
+ * from a previous execution run, and delete the route.
+ */
+
+void OSPF::remnant_notification(InAddr net, InMask mask)
+
+{
+    INrte *rte;
+
+    if (!(rte = inrttbl->find(net, mask)) || !rte->valid()) {
+        if (spflog(LOG_REMNANT, 5)) {
+	    log(&net, &mask);
+	}
+	sys->rtdel(net, mask, 0);
     }
 }
 
diff -X exclude_files -Nabur ospfd2.1/src/ospf.h ospfd2.2/src/ospf.h
--- ospfd2.1/src/ospf.h	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/ospf.h	Mon May 14 14:27:10 2001
@@ -87,6 +87,7 @@
     bool delete_neighbors; // Neighbors being deleted?
     AVLtree phyints;	// Physical interfaces
     AVLtree krtdeletes;	// Deleted, unsynced kernel routing entries
+    bool need_remnants; // Yet to get remnants?
     // Flooding queues
     int	n_local_flooded;// AS-external-LSAs originated this tick
     ExRtData *ases_pending; // Pending AS-external-LSA originations
@@ -265,12 +266,13 @@
     void log(InAddr *addr);
     void log(class LSA *);
     void log(class INrte *);
+    void log(InAddr *addr, InMask *mask);
 
   public:
     // Version numbers
     enum {
 	vmajor = 2,	// Major version number
-	vminor = 1,	// Minor version number
+	vminor = 2,	// Minor version number
     };
 
     // Entry points into the OSPF code
@@ -287,6 +289,7 @@
     void phy_up(int phyint);
     void phy_down(int phyint);
     void krt_delete_notification(InAddr net, InMask mask);
+    void remnant_notification(InAddr net, InMask mask);
     MPath *ip_lookup(InAddr dest);
     InAddr ip_source(InAddr dest);
     InAddr if_addr(int phyint);
diff -X exclude_files -Nabur ospfd2.1/src/spflog.h ospfd2.2/src/spflog.h
--- ospfd2.1/src/spflog.h	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/spflog.h	Mon May 14 14:27:10 2001
@@ -83,6 +83,8 @@
     IGMP_RCV,		// Received IGMP packet
     LOG_SPFDEBUG,	// Debug statements
     LOG_KRTSYNC,	// Synch kernel routing entry
+    LOG_REMNANT,	// Deleting remnant routing entry
+    LOG_DEBUGGING,	// Debug statements
     MAXLOG,		// KEEP THIS LAST!!!!
 };
 
diff -X exclude_files -Nabur ospfd2.1/src/spfutil.C ospfd2.2/src/spfutil.C
--- ospfd2.1/src/spfutil.C	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/spfutil.C	Mon May 14 14:27:10 2001
@@ -408,6 +408,10 @@
 	return("DEBUG");
       case LOG_KRTSYNC:
 	return("Synching kernel routing entry");
+      case LOG_REMNANT:
+	return("Deleting remnant");
+      case LOG_DEBUGGING:
+	return("");
       default:
 	break;
     }
@@ -701,6 +705,28 @@
     log(".");
     log((int) ptr[3]);
 }
+
+/* Log a network/mask combination in CIDR format.
+ */
+
+void OSPF::log(InAddr *addr, InMask *mask)
+
+{
+    int prefix_len;
+    int bit;
+
+    prefix_len = 32;
+    bit = 1;
+    while (prefix_len > 0 && (bit & *mask) == 0) {
+	prefix_len--;
+	bit = bit << 1;
+    }
+
+    log(addr);
+    log("/");
+    log(prefix_len);
+}
+
 
 /* Initialize the OspfSysCalls class. Time begins at zero.
  */
diff -X exclude_files -Nabur ospfd2.1/src/system.h ospfd2.2/src/system.h
--- ospfd2.1/src/system.h	Thu Apr 19 17:50:47 2001
+++ ospfd2.2/src/system.h	Mon May 14 14:27:10 2001
@@ -43,6 +43,7 @@
     virtual void rtdel(InAddr, InMask, MPath *ompp)=0;
     virtual void add_mcache(InAddr, InAddr, MCache *)=0;
     virtual void del_mcache(InAddr src, InAddr group)=0;
+    virtual void upload_remnants()=0;
     virtual void monitor_response(struct MonMsg *, uns16, int, int)=0;
     virtual char *phyname(int phyint)=0;
     virtual void sys_spflog(int msgno, char *msgbuf)=0;

.