Merge pull request #2200 from sever-sever/T5533-eq

T5533: Fix VRRP IPv6 FAULT state due to IPv6 tentative state

1 files changed, 28 insertions, 0 deletions

diff --git a/python/vyos/util.py b/python/vyos/util.py
index 20c743b35..e83a17e18 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -920,6 +920,34 @@ def is_ipv6_enabled() -> bool:
     """ Check if IPv6 support on the system is enabled or not """
     return (sysctl_read('net.ipv6.conf.all.disable_ipv6') == '0')
 
+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.util 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 interface_exists(interface) -> bool:
     import os
     return os.path.exists(f'/sys/class/net/{interface}')