diff --git a/python/vyos/utils/network.py b/python/vyos/utils/network.py
index 2f181d8d9..bc6899e45 100644
--- a/python/vyos/utils/network.py
+++ b/python/vyos/utils/network.py
@@ -1,417 +1,448 @@
 # Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
 # License as published by the Free Software Foundation; either
 # version 2.1 of the License, or (at your option) any later version.
 #
 # This library 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
 # Lesser General Public License for more details.
 #
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 def _are_same_ip(one, two):
     from socket import AF_INET
     from socket import AF_INET6
     from socket import inet_pton
     from vyos.template import is_ipv4
     # compare the binary representation of the IP
     f_one = AF_INET if is_ipv4(one) else AF_INET6
     s_two = AF_INET if is_ipv4(two) else AF_INET6
     return inet_pton(f_one, one) == inet_pton(f_one, two)
 
 def get_protocol_by_name(protocol_name):
     """Get protocol number by protocol name
 
        % get_protocol_by_name('tcp')
        % 6
     """
     import socket
     try:
         protocol_number = socket.getprotobyname(protocol_name)
         return protocol_number
     except socket.error:
         return protocol_name
 
 def interface_exists(interface) -> bool:
     import os
     return os.path.exists(f'/sys/class/net/{interface}')
 
 def interface_exists_in_netns(interface_name, netns):
     from vyos.utils.process import rc_cmd
     rc, out = rc_cmd(f'ip netns exec {netns} ip link show dev {interface_name}')
     if rc == 0:
         return True
     return False
 
 def get_vrf_members(vrf: str) -> list:
     """
     Get list of interface VRF members
     :param vrf: str
     :return: list
     """
     import json
     from vyos.utils.process import cmd
     if not interface_exists(vrf):
         raise ValueError(f'VRF "{vrf}" does not exist!')
     output = cmd(f'ip --json --brief link show master {vrf}')
     answer = json.loads(output)
     interfaces = []
     for data in answer:
         if 'ifname' in data:
             interfaces.append(data.get('ifname'))
     return interfaces
 
 def get_interface_vrf(interface):
     """ Returns VRF of given interface """
     from vyos.utils.dict import dict_search
     from vyos.utils.network import get_interface_config
     tmp = get_interface_config(interface)
     if dict_search('linkinfo.info_slave_kind', tmp) == 'vrf':
         return tmp['master']
     return 'default'
 
 def get_interface_config(interface):
     """ Returns the used encapsulation protocol for given interface.
         If interface does not exist, None is returned.
     """
     import os
     if not os.path.exists(f'/sys/class/net/{interface}'):
         return None
     from json import loads
     from vyos.utils.process import cmd
     tmp = loads(cmd(f'ip --detail --json link show dev {interface}'))[0]
     return tmp
 
 def get_interface_address(interface):
     """ Returns the used encapsulation protocol for given interface.
         If interface does not exist, None is returned.
     """
     import os
     if not os.path.exists(f'/sys/class/net/{interface}'):
         return None
     from json import loads
     from vyos.utils.process import cmd
     tmp = loads(cmd(f'ip --detail --json addr show dev {interface}'))[0]
     return tmp
 
 def get_interface_namespace(iface):
     """
        Returns wich netns the interface belongs to
     """
     from json import loads
     from vyos.utils.process import cmd
     # Check if netns exist
     tmp = loads(cmd(f'ip --json netns ls'))
     if len(tmp) == 0:
         return None
 
     for ns in tmp:
         netns = f'{ns["name"]}'
         # Search interface in each netns
         data = loads(cmd(f'ip netns exec {netns} ip --json link show'))
         for tmp in data:
             if iface == tmp["ifname"]:
                 return netns
 
+def is_ipv6_tentative(iface: str, ipv6_address: str) -> bool:
+    """Check if IPv6 address is in tentative state.
+
+    This function checks if an IPv6 address on a specific network interface is
+    in the tentative state. IPv6 tentative addresses are not fully configured
+    and are undergoing Duplicate Address Detection (DAD) to ensure they are
+    unique on the network.
+
+    Args:
+        iface (str): The name of the network interface.
+        ipv6_address (str): The IPv6 address to check.
+
+    Returns:
+        bool: True if the IPv6 address is tentative, False otherwise.
+    """
+    import json
+    from vyos.utils.process import rc_cmd
+
+    rc, out = rc_cmd(f'ip -6 --json address show dev {iface} scope global')
+    if rc:
+        return False
+
+    data = json.loads(out)
+    for addr_info in data[0]['addr_info']:
+        if (
+            addr_info.get('local') == ipv6_address and
+            addr_info.get('tentative', False)
+        ):
+            return True
+    return False
+
 def is_wwan_connected(interface):
     """ Determine if a given WWAN interface, e.g. wwan0 is connected to the
     carrier network or not """
     import json
     from vyos.utils.process import cmd
 
     if not interface.startswith('wwan'):
         raise ValueError(f'Specified interface "{interface}" is not a WWAN interface')
 
     # ModemManager is required for connection(s) - if service is not running,
     # there won't be any connection at all!
     if not is_systemd_service_active('ModemManager.service'):
         return False
 
     modem = interface.lstrip('wwan')
 
     tmp = cmd(f'mmcli --modem {modem} --output-json')
     tmp = json.loads(tmp)
 
     # return True/False if interface is in connected state
     return dict_search('modem.generic.state', tmp) == 'connected'
 
 def get_bridge_fdb(interface):
     """ Returns the forwarding database entries for a given interface """
     import os
     if not os.path.exists(f'/sys/class/net/{interface}'):
         return None
     from json import loads
     from vyos.utils.process import cmd
     tmp = loads(cmd(f'bridge -j fdb show dev {interface}'))
     return tmp
 
 def get_all_vrfs():
     """ Return a dictionary of all system wide known VRF instances """
     from json import loads
     from vyos.utils.process import cmd
     tmp = loads(cmd('ip --json vrf list'))
     # Result is of type [{"name":"red","table":1000},{"name":"blue","table":2000}]
     # so we will re-arrange it to a more nicer representation:
     # {'red': {'table': 1000}, 'blue': {'table': 2000}}
     data = {}
     for entry in tmp:
         name = entry.pop('name')
         data[name] = entry
     return data
 
 def mac2eui64(mac, prefix=None):
     """
     Convert a MAC address to a EUI64 address or, with prefix provided, a full
     IPv6 address.
     Thankfully copied from https://gist.github.com/wido/f5e32576bb57b5cc6f934e177a37a0d3
     """
     import re
     from ipaddress import ip_network
     # http://tools.ietf.org/html/rfc4291#section-2.5.1
     eui64 = re.sub(r'[.:-]', '', mac).lower()
     eui64 = eui64[0:6] + 'fffe' + eui64[6:]
     eui64 = hex(int(eui64[0:2], 16) ^ 2)[2:].zfill(2) + eui64[2:]
 
     if prefix is None:
         return ':'.join(re.findall(r'.{4}', eui64))
     else:
         try:
             net = ip_network(prefix, strict=False)
             euil = int('0x{0}'.format(eui64), 16)
             return str(net[euil])
         except:  # pylint: disable=bare-except
             return
 
 def check_port_availability(ipaddress, port, protocol):
     """
     Check if port is available and not used by any service
     Return False if a port is busy or IP address does not exists
     Should be used carefully for services that can start listening
     dynamically, because IP address may be dynamic too
     """
     from socketserver import TCPServer, UDPServer
     from ipaddress import ip_address
 
     # verify arguments
     try:
         ipaddress = ip_address(ipaddress).compressed
     except:
         raise ValueError(f'The {ipaddress} is not a valid IPv4 or IPv6 address')
     if port not in range(1, 65536):
         raise ValueError(f'The port number {port} is not in the 1-65535 range')
     if protocol not in ['tcp', 'udp']:
         raise ValueError(f'The protocol {protocol} is not supported. Only tcp and udp are allowed')
 
     # check port availability
     try:
         if protocol == 'tcp':
             server = TCPServer((ipaddress, port), None, bind_and_activate=True)
         if protocol == 'udp':
             server = UDPServer((ipaddress, port), None, bind_and_activate=True)
         server.server_close()
     except Exception as e:
         # errno.h:
         #define EADDRINUSE  98  /* Address already in use */
         if e.errno == 98:
             return False
 
     return True
 
 def is_listen_port_bind_service(port: int, service: str) -> bool:
     """Check if listen port bound to expected program name
     :param port: Bind port
     :param service: Program name
     :return: bool
 
     Example:
         % is_listen_port_bind_service(443, 'nginx')
         True
         % is_listen_port_bind_service(443, 'ocserv-main')
         False
     """
     from psutil import net_connections as connections
     from psutil import Process as process
     for connection in connections():
         addr = connection.laddr
         pid = connection.pid
         pid_name = process(pid).name()
         pid_port = addr.port
         if service == pid_name and port == pid_port:
             return True
     return False
 
 def is_ipv6_link_local(addr):
     """ Check if addrsss is an IPv6 link-local address. Returns True/False """
     from ipaddress import ip_interface
     from vyos.template import is_ipv6
     addr = addr.split('%')[0]
     if is_ipv6(addr):
         if ip_interface(addr).is_link_local:
             return True
 
     return False
 
 def is_addr_assigned(ip_address, vrf=None) -> bool:
     """ Verify if the given IPv4/IPv6 address is assigned to any interface """
     from netifaces import interfaces
     from vyos.utils.network import get_interface_config
     from vyos.utils.dict import dict_search
 
     for interface in interfaces():
         # Check if interface belongs to the requested VRF, if this is not the
         # case there is no need to proceed with this data set - continue loop
         # with next element
         tmp = get_interface_config(interface)
         if dict_search('master', tmp) != vrf:
             continue
 
         if is_intf_addr_assigned(interface, ip_address):
             return True
 
     return False
 
 def is_intf_addr_assigned(intf, address) -> bool:
     """
     Verify if the given IPv4/IPv6 address is assigned to specific interface.
     It can check both a single IP address (e.g. 192.0.2.1 or a assigned CIDR
     address 192.0.2.1/24.
     """
     from vyos.template import is_ipv4
 
     from netifaces import ifaddresses
     from netifaces import AF_INET
     from netifaces import AF_INET6
 
     # check if the requested address type is configured at all
     # {
     # 17: [{'addr': '08:00:27:d9:5b:04', 'broadcast': 'ff:ff:ff:ff:ff:ff'}],
     # 2:  [{'addr': '10.0.2.15', 'netmask': '255.255.255.0', 'broadcast': '10.0.2.255'}],
     # 10: [{'addr': 'fe80::a00:27ff:fed9:5b04%eth0', 'netmask': 'ffff:ffff:ffff:ffff::'}]
     # }
     try:
         addresses = ifaddresses(intf)
     except ValueError as e:
         print(e)
         return False
 
     # determine IP version (AF_INET or AF_INET6) depending on passed address
     addr_type = AF_INET if is_ipv4(address) else AF_INET6
 
     # Check every IP address on this interface for a match
     netmask = None
     if '/' in address:
         address, netmask = address.split('/')
     for ip in addresses.get(addr_type, []):
         # ip can have the interface name in the 'addr' field, we need to remove it
         # {'addr': 'fe80::a00:27ff:fec5:f821%eth2', 'netmask': 'ffff:ffff:ffff:ffff::'}
         ip_addr = ip['addr'].split('%')[0]
 
         if not _are_same_ip(address, ip_addr):
             continue
 
         # we do not have a netmask to compare against, they are the same
         if not netmask:
             return True
 
         prefixlen = ''
         if is_ipv4(ip_addr):
             prefixlen = sum([bin(int(_)).count('1') for _ in ip['netmask'].split('.')])
         else:
             prefixlen = sum([bin(int(_,16)).count('1') for _ in ip['netmask'].split('/')[0].split(':') if _])
 
         if str(prefixlen) == netmask:
             return True
 
     return False
 
 def is_loopback_addr(addr):
     """ Check if supplied IPv4/IPv6 address is a loopback address """
     from ipaddress import ip_address
     return ip_address(addr).is_loopback
 
 def is_wireguard_key_pair(private_key: str, public_key:str) -> bool:
     """
      Checks if public/private keys are keypair
     :param private_key: Wireguard private key
     :type private_key: str
     :param public_key: Wireguard public key
     :type public_key: str
     :return: If public/private keys are keypair returns True else False
     :rtype: bool
     """
     from vyos.utils.process import cmd
     gen_public_key = cmd('wg pubkey', input=private_key)
     if gen_public_key == public_key:
         return True
     else:
         return False
 
 def is_subnet_connected(subnet, primary=False):
     """
     Verify is the given IPv4/IPv6 subnet is connected to any interface on this
     system.
 
     primary check if the subnet is reachable via the primary IP address of this
     interface, or in other words has a broadcast address configured. ISC DHCP
     for instance will complain if it should listen on non broadcast interfaces.
 
     Return True/False
     """
     from ipaddress import ip_address
     from ipaddress import ip_network
 
     from netifaces import ifaddresses
     from netifaces import interfaces
     from netifaces import AF_INET
     from netifaces import AF_INET6
 
     from vyos.template import is_ipv6
 
     # determine IP version (AF_INET or AF_INET6) depending on passed address
     addr_type = AF_INET
     if is_ipv6(subnet):
         addr_type = AF_INET6
 
     for interface in interfaces():
         # check if the requested address type is configured at all
         if addr_type not in ifaddresses(interface).keys():
             continue
 
         # An interface can have multiple addresses, but some software components
         # only support the primary address :(
         if primary:
             ip = ifaddresses(interface)[addr_type][0]['addr']
             if ip_address(ip) in ip_network(subnet):
                 return True
         else:
             # Check every assigned IP address if it is connected to the subnet
             # in question
             for ip in ifaddresses(interface)[addr_type]:
                 # remove interface extension (e.g. %eth0) that gets thrown on the end of _some_ addrs
                 addr = ip['addr'].split('%')[0]
                 if ip_address(addr) in ip_network(subnet):
                     return True
 
     return False
 
 def is_afi_configured(interface, afi):
     """ Check if given address family is configured, or in other words - an IP
     address is assigned to the interface. """
     from netifaces import ifaddresses
     from netifaces import AF_INET
     from netifaces import AF_INET6
 
     if afi not in [AF_INET, AF_INET6]:
         raise ValueError('Address family must be in [AF_INET, AF_INET6]')
 
     try:
         addresses = ifaddresses(interface)
     except ValueError as e:
         print(e)
         return False
 
     return afi in addresses
diff --git a/src/conf_mode/high-availability.py b/src/conf_mode/high-availability.py
index 626a3757e..0121df11c 100755
--- a/src/conf_mode/high-availability.py
+++ b/src/conf_mode/high-availability.py
@@ -1,185 +1,201 @@
 #!/usr/bin/env python3
 #
 # Copyright (C) 2018-2023 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
 # published by the Free Software Foundation.
 #
 # 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, see <http://www.gnu.org/licenses/>.
 
 
+import time
+
 from sys import exit
 from ipaddress import ip_interface
 from ipaddress import IPv4Interface
 from ipaddress import IPv6Interface
 
 from vyos.base import Warning
 from vyos.config import Config
 from vyos.ifconfig.vrrp import VRRP
 from vyos.template import render
 from vyos.template import is_ipv4
 from vyos.template import is_ipv6
+from vyos.utils.network import is_ipv6_tentative
 from vyos.utils.process import call
 from vyos import ConfigError
 from vyos import airbag
 airbag.enable()
 
+
 def get_config(config=None):
     if config:
         conf = config
     else:
         conf = Config()
 
     base = ['high-availability']
     if not conf.exists(base):
         return None
 
     ha = conf.get_config_dict(base, key_mangling=('-', '_'),
                               no_tag_node_value_mangle=True,
                               get_first_key=True, with_defaults=True)
 
     ## Get the sync group used for conntrack-sync
     conntrack_path = ['service', 'conntrack-sync', 'failover-mechanism', 'vrrp', 'sync-group']
     if conf.exists(conntrack_path):
         ha['conntrack_sync_group'] = conf.return_value(conntrack_path)
 
     return ha
 
 def verify(ha):
     if not ha or 'disable' in ha:
         return None
 
     used_vrid_if = []
     if 'vrrp' in ha and 'group' in ha['vrrp']:
         for group, group_config in ha['vrrp']['group'].items():
             # Check required fields
             if 'vrid' not in group_config:
                 raise ConfigError(f'VRID is required but not set in VRRP group "{group}"')
 
             if 'interface' not in group_config:
                 raise ConfigError(f'Interface is required but not set in VRRP group "{group}"')
 
             if 'address' not in group_config:
                 raise ConfigError(f'Virtual IP address is required but not set in VRRP group "{group}"')
 
             if 'authentication' in group_config:
                 if not {'password', 'type'} <= set(group_config['authentication']):
                     raise ConfigError(f'Authentication requires both type and passwortd to be set in VRRP group "{group}"')
 
             if 'health_check' in group_config:
                 health_check_types = ["script", "ping"]
                 from vyos.utils.dict import check_mutually_exclusive_options
                 try:
                     check_mutually_exclusive_options(group_config["health_check"], health_check_types, required=True)
                 except ValueError:
                     Warning(f'Health check configuration for VRRP group "{group}" will remain unused ' \
                             f'until it has one of the following options: {health_check_types}')
                     # XXX: health check has default options so we need to remove it
                     # to avoid generating useless config statements in keepalived.conf
                     del group_config["health_check"]
 
             # Keepalived doesn't allow mixing IPv4 and IPv6 in one group, so we mirror that restriction
             # We also need to make sure VRID is not used twice on the same interface with the
             # same address family.
 
             interface = group_config['interface']
             vrid = group_config['vrid']
 
             # XXX: filter on map object is destructive, so we force it to list.
             # Additionally, filter objects always evaluate to True, empty or not,
             # so we force them to lists as well.
             vaddrs = list(map(lambda i: ip_interface(i), group_config['address']))
             vaddrs4 = list(filter(lambda x: isinstance(x, IPv4Interface), vaddrs))
             vaddrs6 = list(filter(lambda x: isinstance(x, IPv6Interface), vaddrs))
 
             if vaddrs4 and vaddrs6:
                 raise ConfigError(f'VRRP group "{group}" mixes IPv4 and IPv6 virtual addresses, this is not allowed.\n' \
                                   'Create individual groups for IPv4 and IPv6!')
             if vaddrs4:
                 tmp = {'interface': interface, 'vrid': vrid, 'ipver': 'IPv4'}
                 if tmp in used_vrid_if:
                     raise ConfigError(f'VRID "{vrid}" can only be used once on interface "{interface} with address family IPv4"!')
                 used_vrid_if.append(tmp)
 
                 if 'hello_source_address' in group_config:
                     if is_ipv6(group_config['hello_source_address']):
                         raise ConfigError(f'VRRP group "{group}" uses IPv4 but hello-source-address is IPv6!')
 
                 if 'peer_address' in group_config:
                     if is_ipv6(group_config['peer_address']):
                         raise ConfigError(f'VRRP group "{group}" uses IPv4 but peer-address is IPv6!')
 
             if vaddrs6:
                 tmp = {'interface': interface, 'vrid': vrid, 'ipver': 'IPv6'}
                 if tmp in used_vrid_if:
                     raise ConfigError(f'VRID "{vrid}" can only be used once on interface "{interface} with address family IPv6"!')
                 used_vrid_if.append(tmp)
 
                 if 'hello_source_address' in group_config:
                     if is_ipv4(group_config['hello_source_address']):
                         raise ConfigError(f'VRRP group "{group}" uses IPv6 but hello-source-address is IPv4!')
 
                 if 'peer_address' in group_config:
                     if is_ipv4(group_config['peer_address']):
                         raise ConfigError(f'VRRP group "{group}" uses IPv6 but peer-address is IPv4!')
     # Check sync groups
     if 'vrrp' in ha and 'sync_group' in ha['vrrp']:
         for sync_group, sync_config in ha['vrrp']['sync_group'].items():
             if 'member' in sync_config:
                 for member in sync_config['member']:
                     if member not in ha['vrrp']['group']:
                         raise ConfigError(f'VRRP sync-group "{sync_group}" refers to VRRP group "{member}", '\
                                           'but it does not exist!')
 
     # Virtual-server
     if 'virtual_server' in ha:
         for vs, vs_config in ha['virtual_server'].items():
 
             if 'address' not in vs_config and 'fwmark' not in vs_config:
                 raise ConfigError('Either address or fwmark is required '
                                   f'but not set for virtual-server "{vs}"')
 
             if 'port' not in vs_config and 'fwmark' not in vs_config:
                 raise ConfigError(f'Port or fwmark is required but not set for virtual-server "{vs}"')
             if 'port' in vs_config and 'fwmark' in vs_config:
                 raise ConfigError(f'Cannot set both port and fwmark for virtual-server "{vs}"')
             if 'real_server' not in vs_config:
                 raise ConfigError(f'Real-server ip is required but not set for virtual-server "{vs}"')
         # Real-server
         for rs, rs_config in vs_config['real_server'].items():
             if 'port' not in rs_config:
                 raise ConfigError(f'Port is required but not set for virtual-server "{vs}" real-server "{rs}"')
 
 
 def generate(ha):
     if not ha or 'disable' in ha:
         return None
 
     render(VRRP.location['config'], 'high-availability/keepalived.conf.j2', ha)
     return None
 
 def apply(ha):
     service_name = 'keepalived.service'
     if not ha or 'disable' in ha:
         call(f'systemctl stop {service_name}')
         return None
 
+    # Check if IPv6 address is tentative T5533
+    for group, group_config in ha['vrrp']['group'].items():
+        if 'hello_source_address' in group_config:
+            if is_ipv6(group_config['hello_source_address']):
+                ipv6_address = group_config['hello_source_address']
+                interface = group_config['interface']
+                checks = 20
+                interval = 0.1
+                for _ in range(checks):
+                    if is_ipv6_tentative(interface, ipv6_address):
+                        time.sleep(interval)
+
     call(f'systemctl reload-or-restart {service_name}')
     return None
 
 if __name__ == '__main__':
     try:
         c = get_config()
         verify(c)
         generate(c)
         apply(c)
     except ConfigError as e:
         print(e)
         exit(1)