diff -X exclude_files -Nabur ospfd1.22/linux/ospfd.tcl ospfd1.23/linux/ospfd.tcl
--- ospfd1.22/linux/ospfd.tcl	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/linux/ospfd.tcl	Fri Jan 19 15:20:44 2001
@@ -48,6 +48,7 @@
 set global_att(host) 0
 set global_att(refresh_rate) 0
 set global_att(PPAdjLimit) 0
+set global_att(random_refresh) 0
 
 ###############################################################
 # Top-level commands to set global parameters
@@ -64,6 +65,7 @@
 #	log_level %no
 #	refresh_rate %seconds
 #	PPAdjLimit %no
+#	random_refresh
 ###############################################################
 
 proc ospfExtLsdbLimit {val} {
@@ -110,6 +112,10 @@
     global global_att
     set global_att(PPAdjLimit) $nadj
 }
+proc random_refresh {} {
+    global global_att
+    set global_att(random_refresh) 1
+}
 
 ###############################################################
 # Area configuration:
@@ -437,7 +443,7 @@
 	    $global_att(new_flood_rate) $global_att(max_rxmt_window) \
 	    $global_att(max_dds) $global_att(base_level) \
 	    $global_att(host) $global_att(refresh_rate) \
-	    $global_att(PPAdjLimit)
+	    $global_att(PPAdjLimit) $global_att(random_refresh)
     foreach a $areas {
 	sendarea $a $area_att($a,stub) $area_att($a,dflt_cost) \
 		$area_att($a,import_summs)
diff -X exclude_files -Nabur ospfd1.22/linux/ospfd_linux.C ospfd1.23/linux/ospfd_linux.C
--- ospfd1.22/linux/ospfd_linux.C	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/linux/ospfd_linux.C	Fri Jan 19 15:20:44 2001
@@ -808,6 +808,7 @@
     m.log_priority = atoi(argv[8]);
     m.refresh_rate = atoi(argv[10]);
     m.PPAdjLimit = atoi(argv[11]);
+    m.random_refresh = atoi(argv[12]);
     ospf->cfgOspf(&m);
 
     return(TCL_OK);
diff -X exclude_files -Nabur ospfd1.22/ospf_sim/ospf_sim.tcl ospfd1.23/ospf_sim/ospf_sim.tcl
--- ospfd1.22/ospf_sim/ospf_sim.tcl	Wed Jan 17 16:00:07 2001
+++ ospfd1.23/ospf_sim/ospf_sim.tcl	Fri Jan 19 15:20:46 2001
@@ -40,6 +40,7 @@
 global {vlinks}
 global {sessions}
 global {session_ids}
+global {random_refresh_flag}
 
 set routers {}
 set areas {}
@@ -55,6 +56,7 @@
 set neighbor_index 0
 set port_index 0
 set session_ids 0
+set random_refresh_flag 0
 
 set PING 0
 set TRACEROUTE 1
@@ -404,6 +406,15 @@
 }
 
 ###############################################################
+# Set *all* simulated routers to randomly refresh.
+# By default, this function is disabled.
+###############################################################
+
+proc random_refresh {} {
+    global random_refresh_flag
+    set random_refresh_flag 1
+}
+###############################################################
 # Send entire configuration to a
 # given router (i.e., simulated ospfd).
 ###############################################################
@@ -411,9 +422,9 @@
 proc sendcfg {rtr_id} {
     global router_att area_att ifc_att vlink_att
     global aggr_att route_att host_att nbr_att node_att
-    global networks network_att
+    global networks network_att random_refresh_flag
     sendgen $rtr_id $router_att($rtr_id,host) $router_att($rtr_id,mospf) \
-	    $router_att($rtr_id,PPAdjLimit)
+	    $router_att($rtr_id,PPAdjLimit) $random_refresh_flag
     foreach a $router_att($rtr_id,areas) {
 	sendarea $rtr_id $a $area_att($a,stub) $area_att($a,default_cost) \
 		$area_att($a,import)
@@ -1400,9 +1411,12 @@
     global router_att area_att ifc_att vlink_att vlinks
     global aggr_att route_att host_att nbr_att node_att
     global network_att aggr_att route_att nbr_att
-    global host_att
+    global host_att random_refresh_flag
 
     set f [open $config_file w]
+    if {$random_refresh_flag != 0} {
+	puts $f "random_refresh"
+    }
     foreach id $routers {
 	if {$router_att($id,host) == 0} {
 	    puts $f [concat "router" $id $node_att($id,x) $node_att($id,y) \
diff -X exclude_files -Nabur ospfd1.22/ospf_sim/sim.C ospfd1.23/ospf_sim/sim.C
--- ospfd1.22/ospf_sim/sim.C	Wed Jan 17 16:00:07 2001
+++ ospfd1.23/ospf_sim/sim.C	Fri Jan 19 15:20:46 2001
@@ -942,6 +942,7 @@
     m.log_priority = 2;
     m.refresh_rate = 6000;
     m.PPAdjLimit = atoi(argv[4]);
+    m.random_refresh = atoi(argv[5]);
     node->pktdata.queue_xpkt(&m, SIM_CONFIG, CfgType_Gen, len);
 
     return(TCL_OK);
diff -X exclude_files -Nabur ospfd1.22/src/config.h ospfd1.23/src/config.h
--- ospfd1.22/src/config.h	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/src/config.h	Fri Jan 19 15:20:44 2001
@@ -55,6 +55,7 @@
     int log_priority;	// Logging message priority
     int32 refresh_rate;	// Rate to refresh DoNotAge LSAs
     uns32 PPAdjLimit;	// Max # p-p adjacencies to neighbor
+    int random_refresh;	// Should we spread out LSA refreshes?
 
     void set_defaults();
 };
diff -X exclude_files -Nabur ospfd1.22/src/dbage.C ospfd1.23/src/dbage.C
--- ospfd1.22/src/dbage.C	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/src/dbage.C	Fri Jan 19 15:20:44 2001
@@ -27,6 +27,8 @@
 // Declarations of statics
 LSA *LSA::AgeBins[MaxAge+1];	// Aging Bins
 int LSA::Bin0;			// Current age 0 bin
+int32 LSA::RefreshBins[MaxAgeDiff];// Refresh bins
+int LSA::RefreshBin0;		// Current refresh bin
 
 
 /* Start aging an LSA. Remove it from an existing bin, if necessary.
@@ -162,6 +164,7 @@
     refresh_lsas();
     maxage_lsas();
     refresh_donotages();
+    do_random_refreshes();
 
     // Finish any flooding that was caused by age routines
     send_updates();
@@ -259,11 +262,8 @@
 	next_lsa = lsap->lsa_agefwd;
 	if (lsap->do_not_age())
 	    continue;
-	if (lsap->adv_rtr() == myid) {
-	    if (spflog(LOG_LSAREFR, 1))
-		log(lsap);
-	    lsap->reoriginate(true);
-	}
+	if (lsap->adv_rtr() == myid)
+	    schedule_refresh(lsap);
     }
 }
 
@@ -322,11 +322,8 @@
 	    continue;
 	if (!lsap->do_not_age())
 	    continue;
-	if (lsap->lsa_hour >= hour) {
-	    if (spflog(LOG_DNAREFR, 1))
-		log(lsap);
-	    lsap->reoriginate(true);
-	}
+	if (lsap->lsa_hour >= hour)
+	    schedule_refresh(lsap);
     }
 }
 
@@ -461,4 +458,70 @@
 	}
 	delete iter;
     }
+}
+
+/* The official time to refresh a given LSA has arrived.
+ * If configured to randomly refresh, delay the refresh
+ * randomly up to MaxAgeDiff seconds. Otherwise (the default)
+ * refresh the LSA immediately by forcing a reorigination.
+ */
+
+void OSPF::schedule_refresh(LSA *lsap)
+
+{
+    int slot;
+
+    if (!random_refresh) {
+	int msgno;
+	msgno = lsap->do_not_age() ? LOG_DNAREFR : LOG_LSAREFR;
+	if (spflog(msgno, 1))
+	    log(lsap);
+        lsap->reoriginate(true);
+    }
+
+    /* We are going to randomly delay reorigination
+     * until some time in the next MaxAgeDiff
+     * seconds. Note: we don't care where the current
+     * refresh bin is.
+     */
+    slot = Timer::random_period(MaxAgeDiff);
+    if (slot < 0 || slot >= MaxAgeDiff)
+        slot = LSA::RefreshBin0;
+    LSA::RefreshBins[slot]++;
+    pending_refresh.addEntry(lsap);
+}
+
+/* Go through the list of delayed originations, and refresh
+ * the number that have been scheduled for this 
+ * timeslot (width one second). LSAs that have already
+ * been overwritten or deleted still count against the tally,
+ * but are of course not refreshed.
+ */
+
+void OSPF::do_random_refreshes()
+
+{
+    int count;
+    LSA *lsap;
+    LsaListIterator iter(&pending_refresh);
+
+    count = LSA::RefreshBins[LSA::RefreshBin0];
+    LSA::RefreshBins[LSA::RefreshBin0] = 0;
+    // Refresh up to count LSAs
+    for (; count > 0 && (lsap = iter.get_next()); count--) {
+        int msgno;
+	if (!lsap->valid() || lsap->lsa_age() == MaxAge) {
+	    iter.remove_current();
+	    continue;
+	}
+	msgno = lsap->do_not_age() ? LOG_DNAREFR : LOG_LSAREFR;
+	if (spflog(msgno, 1))
+	    log(lsap);
+	iter.remove_current();
+        lsap->reoriginate(true);
+    }
+
+    LSA::RefreshBin0++;
+    if (LSA::RefreshBin0 >= MaxAgeDiff)
+        LSA::RefreshBin0 = 0;
 }
diff -X exclude_files -Nabur ospfd1.22/src/lsa.h ospfd1.23/src/lsa.h
--- ospfd1.22/src/lsa.h	Wed Jan 17 16:01:27 2001
+++ ospfd1.23/src/lsa.h	Fri Jan 19 15:20:44 2001
@@ -61,6 +61,8 @@
 
     static  LSA *AgeBins[MaxAge+1];// Aging Bins
     static int Bin0;	// Current age 0 bin
+    static int32 RefreshBins[MaxAgeDiff]; // Refresh bins
+    static int RefreshBin0; // Current refresh bin
 
     void hdr_parse(LShdr *hdr);
     virtual void parse(LShdr *);
diff -X exclude_files -Nabur ospfd1.22/src/ospf.C ospfd1.23/src/ospf.C
--- ospfd1.22/src/ospf.C	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/src/ospf.C	Fri Jan 19 15:20:44 2001
@@ -69,6 +69,7 @@
     host_mode = 0;		// act as router
     refresh_rate = 0;		// Don't originate DoNotAge LSAs
     PPAdjLimit = 0;		// Don't limit p-p adjacencies
+    random_refresh = false;
 
     myaddr = 0;
     n_extImports = 0;
@@ -168,6 +169,7 @@
     replied_list.clear();
     MaxAge_list.clear();
     dbcheck_list.clear();
+    pending_refresh.clear();
     ospfd_membership.clear();
     local_membership.clear();
     multicast_cache.clear();
@@ -179,6 +181,9 @@
     for (int i= 0; i < MaxAge+1; i++)
         LSA::AgeBins[i] = 0;
     LSA::Bin0 = 0;
+    for (int i= 0; i < MaxAgeDiff; i++)
+        LSA::RefreshBins[i] = 0;
+    LSA::RefreshBin0 = 0;
 }
 
 /* Configure global OSPF parameters. Certain parameter
@@ -237,6 +242,8 @@
     base_priority = m->log_priority;
     refresh_rate = m->refresh_rate;
     PPAdjLimit = m->PPAdjLimit;
+    random_refresh = (m->random_refresh != 0);
+
     sys->ip_forward(host_mode == 0);
 
     updated = true;
@@ -263,6 +270,7 @@
     host_mode = 0;	// act as router
     log_priority = 4;	// Base logging priority
     refresh_rate = 0;	// Don't originate DoNotAge LSAs
+    random_refresh = false; // Don't spread out LSA refreshes
     PPAdjLimit = 0;	// Don't limit p-p adjacencies
     sys->ip_forward(true);
 }
diff -X exclude_files -Nabur ospfd1.22/src/ospf.h ospfd1.23/src/ospf.h
--- ospfd1.22/src/ospf.h	Fri Jan 19 15:13:57 2001
+++ ospfd1.23/src/ospf.h	Fri Jan 19 15:20:44 2001
@@ -58,6 +58,7 @@
     byte host_mode;	// Don't forward data packets?
     int32 refresh_rate;	// Rate to refresh DoNotAge LSAs
     uns32 PPAdjLimit;	// Max # p-p adjacencies to neighbor
+    bool random_refresh;// Should we spread out LSA refreshes?
     // Dynamic data
     InAddr myaddr;	// Global address: source on unnumbered
     bool wakeup; 	// Timers running?
@@ -97,6 +98,7 @@
     LsaList MaxAge_list; // MaxAge LSAs, being flushed
     uns32 total_lsas;	// Total number of LSAs in all databases
     LsaList dbcheck_list; // LSAs whose checksum is being verified
+    LsaList pending_refresh; // LSAs awaiting refresh
     // Database Overflow variables
     bool OverflowState;	// true => database has overflowed
     ExitOverflowTimer oflwtim; // Exit overflow timer
@@ -198,6 +200,8 @@
     void refresh_donotages();
     void free_maxage_lsas();
     void donotage_changes();
+    void schedule_refresh(LSA *);
+    void do_random_refreshes();
 
     // LSA origination
     int	self_originated(SpfArea *ap, LShdr *hdr, LSA *database_copy);
@@ -261,7 +265,7 @@
     // Version numbers
     enum {
 	vmajor = 1,	// Major version number
-	vminor = 22,	// Minor version number
+	vminor = 23,	// Minor version number
     };
 
     // Entry points into the OSPF code
diff -X exclude_files -Nabur ospfd1.22/src/timer.C ospfd1.23/src/timer.C
--- ospfd1.22/src/timer.C	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/src/timer.C	Fri Jan 19 15:20:44 2001
@@ -29,7 +29,7 @@
  * Used to jitter timers.
  */
 
-static int random_period(int period)
+static int Timer::random_period(int period)
 
 {
     float fperiod = period;
diff -X exclude_files -Nabur ospfd1.22/src/timer.h ospfd1.23/src/timer.h
--- ospfd1.22/src/timer.h	Wed Jan 17 16:00:04 2001
+++ ospfd1.23/src/timer.h	Fri Jan 19 15:20:44 2001
@@ -36,6 +36,7 @@
 	period = 0;
     }
 
+    static int random_period(int period);
     void stop();
     void restart(int millseconds=0);// Stop and start again
     inline int is_running();

.