apache · NVShawn · Jan 12, 2026
diff --git a/core/src/main/java/com/cloud/agent/api/routing/DhcpEntryCommand.java b/core/src/main/java/com/cloud/agent/api/routing/DhcpEntryCommand.java
@@ -36,6 +36,7 @@ public class DhcpEntryCommand extends NetworkElementCommand {
     private boolean isDefault;
     boolean executeInSequence = false;
     boolean remove;
+    Long leaseTime;
 
     public boolean isRemove() {
         return remove;
@@ -152,4 +153,12 @@ public boolean isDefault() {
     public void setDefault(boolean isDefault) {
         this.isDefault = isDefault;
     }
+
+    public Long getLeaseTime() {
+        return leaseTime;
+    }
+
+    public void setLeaseTime(Long leaseTime) {
+        this.leaseTime = leaseTime;
+    }
 }
diff --git a/core/src/main/java/com/cloud/agent/resource/virtualnetwork/facade/DhcpEntryConfigItem.java b/core/src/main/java/com/cloud/agent/resource/virtualnetwork/facade/DhcpEntryConfigItem.java
@@ -35,7 +35,7 @@ public List<ConfigItem> generateConfig(final NetworkElementCommand cmd) {
         final DhcpEntryCommand command = (DhcpEntryCommand) cmd;
 
         final VmDhcpConfig vmDhcpConfig = new VmDhcpConfig(command.getVmName(), command.getVmMac(), command.getVmIpAddress(), command.getVmIp6Address(), command.getDuid(), command.getDefaultDns(),
-                command.getDefaultRouter(), command.getStaticRoutes(), command.isDefault(), command.isRemove());
+                command.getDefaultRouter(), command.getStaticRoutes(), command.isDefault(), command.isRemove(), command.getLeaseTime());
 
         return generateConfigItems(vmDhcpConfig);
     }

diff --git a/core/src/main/java/com/cloud/agent/resource/virtualnetwork/model/VmDhcpConfig.java b/core/src/main/java/com/cloud/agent/resource/virtualnetwork/model/VmDhcpConfig.java
@@ -29,6 +29,7 @@ public class VmDhcpConfig extends ConfigBase {
     private String defaultGateway;
     private String staticRoutes;
     private boolean defaultEntry;
+    private Long leaseTime;
 
     // Indicate if the entry should be removed when set to true
     private boolean remove;
@@ -39,6 +40,11 @@ public VmDhcpConfig() {
 
     public VmDhcpConfig(String hostName, String macAddress, String ipv4Address, String ipv6Address, String ipv6Duid, String dnsAddresses, String defaultGateway,
             String staticRoutes, boolean defaultEntry, boolean remove) {
+        this(hostName, macAddress, ipv4Address, ipv6Address, ipv6Duid, dnsAddresses, defaultGateway, staticRoutes, defaultEntry, remove, null);
+    }
+
+    public VmDhcpConfig(String hostName, String macAddress, String ipv4Address, String ipv6Address, String ipv6Duid, String dnsAddresses, String defaultGateway,
+            String staticRoutes, boolean defaultEntry, boolean remove, Long leaseTime) {
         super(VM_DHCP);
         this.hostName = hostName;
         this.macAddress = macAddress;
@@ -50,6 +56,7 @@ public VmDhcpConfig(String hostName, String macAddress, String ipv4Address, Stri
         this.staticRoutes = staticRoutes;
         this.defaultEntry = defaultEntry;
         this.remove = remove;
+        this.leaseTime = leaseTime;
     }
 
     public String getHostName() {
@@ -132,4 +139,12 @@ public void setDefaultEntry(boolean defaultEntry) {
         this.defaultEntry = defaultEntry;
     }
 
+    public Long getLeaseTime() {
+        return leaseTime;
+    }
+
+    public void setLeaseTime(Long leaseTime) {
+        this.leaseTime = leaseTime;
+    }
+
 }
diff --git a/scripts/network/exdhcp/dhcpd_edithosts.py b/scripts/network/exdhcp/dhcpd_edithosts.py
@@ -17,18 +17,18 @@
 # under the License.
 
 
-# Usage: dhcpd_edithosts.py mac ip hostname dns gateway nextserver
+# Usage: dhcpd_edithosts.py mac ip hostname dns gateway nextserver [leasetime]
 import sys, os
 from os.path import exists
 from time import sleep
 from os import remove
 
-usage = '''dhcpd_edithosts.py mac ip hostname dns gateway nextserver'''
+usage = '''dhcpd_edithosts.py mac ip hostname dns gateway nextserver [leasetime]'''
 conf_path = "/etc/dhcpd.conf"
 file_lock = "/etc/dhcpd.conf_locked"
 sleep_max = 20
-host_entry = 'host %s { hardware ethernet %s; fixed-address %s; option domain-name-servers %s; option domain-name "%s"; option routers %s; default-lease-time infinite; max-lease-time infinite; min-lease-time infinite; filename "pxelinux.0";}'
-host_entry1 = 'host %s { hardware ethernet %s; fixed-address %s; option domain-name-servers %s; option domain-name "%s"; option routers %s; default-lease-time infinite; max-lease-time infinite; min-lease-time infinite; next-server %s; filename "pxelinux.0";}'
+host_entry = 'host %s { hardware ethernet %s; fixed-address %s; option domain-name-servers %s; option domain-name "%s"; option routers %s; default-lease-time %s; max-lease-time %s; min-lease-time %s; filename "pxelinux.0";}'
+host_entry1 = 'host %s { hardware ethernet %s; fixed-address %s; option domain-name-servers %s; option domain-name "%s"; option routers %s; default-lease-time %s; max-lease-time %s; min-lease-time %s; next-server %s; filename "pxelinux.0";}'
 def lock():
 	if exists(file_lock):
 		count = 0
@@ -59,10 +59,14 @@ def unlock():
 			print "Cannot remove file lock at %s" % file_lock
 			return False
 
-def insert_host_entry(mac, ip, hostname, dns, gateway, next_server):
+def insert_host_entry(mac, ip, hostname, dns, gateway, next_server, lease_time="infinite"):
 	if lock() == False:
 		return 1
 
+	# Convert 0 to 'infinite' for lease time
+	if lease_time == "0":
+		lease_time = "infinite"
+
 	cmd = 'sed -i /"fixed-address %s"/d %s' % (ip, conf_path)
 	ret = os.system(cmd)
 	if ret != 0:
@@ -78,9 +82,9 @@ def insert_host_entry(mac, ip, hostname, dns, gateway, next_server):
 		return 1
 
 	if next_server != "null":
-		entry = host_entry1 % (hostname, mac, ip, dns, "cloudnine.internal", gateway, next_server)
+		entry = host_entry1 % (hostname, mac, ip, dns, "cloudnine.internal", gateway, lease_time, lease_time, lease_time, next_server)
 	else:
-		entry = host_entry % (hostname, mac, ip, dns, "cloudnine.internal", gateway)
+		entry = host_entry % (hostname, mac, ip, dns, "cloudnine.internal", gateway, lease_time, lease_time, lease_time)
 	cmd = '''echo '%s' >> %s''' % (entry, conf_path)
 	ret = os.system(cmd)
 	if ret != 0:
@@ -111,12 +115,13 @@ def insert_host_entry(mac, ip, hostname, dns, gateway, next_server):
 	dns = sys.argv[4]
 	gateway = sys.argv[5]
 	next_server = sys.argv[6]
+	lease_time = sys.argv[7] if len(sys.argv) > 7 else "infinite"
 
 	if exists(conf_path) == False:
 		conf_path = "/etc/dhcp/dhcpd.conf"
 	if exists(conf_path) == False:
 		print "Cannot find dhcpd.conf"
 		sys.exit(1)
 
-	ret = insert_host_entry(mac, ip, hostname, dns, gateway, next_server)
+	ret = insert_host_entry(mac, ip, hostname, dns, gateway, next_server, lease_time)
 	sys.exit(ret)
diff --git a/scripts/network/exdhcp/dnsmasq_edithosts.sh b/scripts/network/exdhcp/dnsmasq_edithosts.sh
@@ -21,6 +21,7 @@
 # $1 : the mac address
 # $2 : the associated ip address
 # $3 : the hostname
+# $4 : the lease time (optional, defaults to 'infinite')
 
 wait_for_dnsmasq () {
   local _pid=$(pidof dnsmasq)
@@ -41,11 +42,17 @@ no_dhcp_release=$?
 [ ! -f /etc/dhcphosts.txt ] && touch /etc/dhcphosts.txt
 [ ! -f /var/lib/misc/dnsmasq.leases ] && touch /var/lib/misc/dnsmasq.leases
 
+# Set lease time, default to 'infinite', convert 0 to 'infinite'
+lease_time=${4:-infinite}
+if [ "$lease_time" = "0" ]; then
+  lease_time=infinite
+fi
+
 sed -i  /$1/d /etc/dhcphosts.txt
 sed -i  /$2,/d /etc/dhcphosts.txt
 sed -i  /$3,/d /etc/dhcphosts.txt
 
-echo "$1,$2,$3,infinite" >>/etc/dhcphosts.txt
+echo "$1,$2,$3,$lease_time" >>/etc/dhcphosts.txt
 
 #release previous dhcp lease if present
 if [ $no_dhcp_release -eq 0 ]

diff --git a/server/src/main/java/com/cloud/configuration/Config.java b/server/src/main/java/com/cloud/configuration/Config.java
@@ -351,6 +351,15 @@ public enum Config {
             ConfigKey.Kind.CSV,
             null),
 
+    DhcpLeaseTimeout(
+            "Network",
+            ManagementServer.class,
+            Integer.class,
+            "dhcp.lease.timeout",
+            "0",
+            "DHCP lease time in seconds for VMs. Use 0 for infinite lease time (default). A non-zero value sets the lease duration in seconds.",
+            null),
+
     //VPN
     RemoteAccessVpnPskLength(
             "Network",

diff --git a/server/src/main/java/com/cloud/network/router/CommandSetupHelper.java b/server/src/main/java/com/cloud/network/router/CommandSetupHelper.java
@@ -296,6 +296,11 @@ public void createDhcpEntryCommand(final VirtualRouter router, final UserVm vm,
         dhcpCommand.setDefault(nic.isDefaultNic());
         dhcpCommand.setRemove(remove);
 
+        // Set DHCP lease timeout from global config (0 = infinite)
+        String leaseTimeStr = _configDao.getValue(Config.DhcpLeaseTimeout.key());
+        Long leaseTime = (leaseTimeStr != null) ? Long.parseLong(leaseTimeStr) : 0L;
+        dhcpCommand.setLeaseTime(leaseTime);
+
         dhcpCommand.setAccessDetail(NetworkElementCommand.ROUTER_IP, _routerControlHelper.getRouterControlIp(router.getId()));
         dhcpCommand.setAccessDetail(NetworkElementCommand.ROUTER_NAME, router.getInstanceName());
         dhcpCommand.setAccessDetail(NetworkElementCommand.ROUTER_GUEST_IP, _routerControlHelper.getRouterIpInNetwork(nic.getNetworkId(), router.getId()));

diff --git a/systemvm/debian/opt/cloud/bin/cs/CsDhcp.py b/systemvm/debian/opt/cloud/bin/cs/CsDhcp.py
@@ -199,12 +199,14 @@ def write_hosts(self):
 
     def add(self, entry):
         self.add_host(entry['ipv4_address'], entry['host_name'])
-        # Lease time set to "infinite" since we properly control all DHCP/DNS config via CloudStack.
+        # Lease time is configurable via CloudStack global config dhcp.lease.timeout
+        # 0 = infinite (default), otherwise the value represents seconds
         # Infinite time helps avoid some edge cases which could cause DHCPNAK being sent to VMs since
         # (RHEL) system lose routes when they receive DHCPNAK.
         # When VM is expunged, its active lease and DHCP/DNS config is properly removed from related files in VR,
         # so the infinite duration of lease does not cause any issues or garbage.
-        lease = 'infinite'
+        lease_time = entry.get('lease_time', 0)
+        lease = 'infinite' if lease_time == 0 else str(lease_time)
 
         if entry['default_entry']:
             self.dhcp_hosts.add("%s,%s,%s,%s" % (entry['mac_address'],

diff --git a/systemvm/debian/opt/cloud/bin/edithosts.sh b/systemvm/debian/opt/cloud/bin/edithosts.sh
@@ -21,7 +21,7 @@
 # edithosts.sh -- edit the dhcphosts file on the routing domain
 
 usage() {
-  printf "Usage: %s: -m <MAC address> -4 <IPv4 address> -6 <IPv6 address> -h <hostname> -d <default router> -n <name server address> -s <Routes> -u <DUID> [-N]\n" $(basename $0) >&2
+  printf "Usage: %s: -m <MAC address> -4 <IPv4 address> -6 <IPv6 address> -h <hostname> -d <default router> -n <name server address> -s <Routes> -u <DUID> -l <lease time> [-N]\n" $(basename $0) >&2
 }
 
 mac=
@@ -33,8 +33,9 @@ dns=
 routes=
 duid=
 nondefault=
+lease_time=infinite
 
-while getopts 'm:4:h:d:n:s:6:u:N' OPTION
+while getopts 'm:4:h:d:n:s:6:u:l:N' OPTION
 do
   case $OPTION in
   m)    mac="$OPTARG"
@@ -53,6 +54,8 @@ do
         ;;
   s)    routes="$OPTARG"
         ;;
+  l)    lease_time="$OPTARG"
+        ;;
   N)    nondefault=1
         ;;
   ?)    usage
@@ -124,17 +127,21 @@ fi
 sed -i  /$host,/d $DHCP_HOSTS
 
 #put in the new entry
+# If lease_time is 0, use 'infinite', otherwise use the value
+if [ "$lease_time" = "0" ]; then
+  lease_time=infinite
+fi
 if [ $ipv4 ]
 then
-  echo "$mac,$ipv4,$host,infinite" >>$DHCP_HOSTS
+  echo "$mac,$ipv4,$host,$lease_time" >>$DHCP_HOSTS
 fi
 if [ $ipv6 ]
 then
   if [ $nondefault ]
   then
-    echo "id:$duid,set:nondefault6,[$ipv6],$host,infinite" >>$DHCP_HOSTS
+    echo "id:$duid,set:nondefault6,[$ipv6],$host,$lease_time" >>$DHCP_HOSTS
   else
-    echo "id:$duid,[$ipv6],$host,infinite" >>$DHCP_HOSTS
+    echo "id:$duid,[$ipv6],$host,$lease_time" >>$DHCP_HOSTS
   fi
 fi