diff --git a/src/hosts/core/models.py b/src/hosts/core/models.py
index db06792..c9dc8ee 100644
--- a/src/hosts/core/models.py
+++ b/src/hosts/core/models.py
@@ -200,40 +200,87 @@ class HostsFile:
 
     def sort_by_ip(self, ascending: bool = True) -> None:
         """
-        Sort entries by IP address, keeping default entries on top.
+        Sort entries by IP address, keeping default entries on top in fixed order.
         
         Args:
             ascending: Sort in ascending order if True, descending if False
         """
-        def sort_key(entry):
+        # Separate default and non-default entries
+        default_entries = [entry for entry in self.entries if entry.is_default_entry()]
+        non_default_entries = [entry for entry in self.entries if not entry.is_default_entry()]
+        
+        def ip_sort_key(entry):
             try:
                 ip_str = entry.ip_address.lstrip('# ')
                 ip_obj = ipaddress.ip_address(ip_str)
-                # Default entries always come first (priority 0), others get priority 1
-                priority = 0 if entry.is_default_entry() else 1
-                # Create a tuple for sorting: (priority, version, ip_int)
-                return (priority, ip_obj.version, int(ip_obj))
+                # Create a tuple for sorting: (version, ip_int)
+                return (ip_obj.version, int(ip_obj))
             except ValueError:
-                # If IP parsing fails, use string comparison with high sort priority
-                priority = 0 if entry.is_default_entry() else 1
-                return (priority, 999, entry.ip_address)
+                # If IP parsing fails, use string comparison
+                return (999, entry.ip_address)
         
-        self.entries.sort(key=sort_key, reverse=not ascending)
+        # Keep default entries in their natural fixed order (don't sort them)
+        # Define the fixed order for default entries
+        default_order = [
+            {"ip": "127.0.0.1", "hostname": "localhost"},
+            {"ip": "255.255.255.255", "hostname": "broadcasthost"},
+            {"ip": "::1", "hostname": "localhost"},
+        ]
+        
+        # Sort default entries according to their fixed order
+        def default_sort_key(entry):
+            for i, default in enumerate(default_order):
+                if (entry.ip_address == default["ip"] and 
+                    entry.hostnames and entry.hostnames[0] == default["hostname"]):
+                    return i
+            return 999  # fallback for any unexpected default entries
+        
+        default_entries.sort(key=default_sort_key)
+        
+        # Sort non-default entries according to the specified direction
+        non_default_entries.sort(key=ip_sort_key, reverse=not ascending)
+        
+        # Combine: default entries always first, then sorted non-default entries
+        self.entries = default_entries + non_default_entries
 
     def sort_by_hostname(self, ascending: bool = True) -> None:
         """
-        Sort entries by first hostname, keeping default entries on top.
+        Sort entries by first hostname, keeping default entries on top in fixed order.
         
         Args:
             ascending: Sort in ascending order if True, descending if False
         """
-        def sort_key(entry):
-            # Default entries always come first (priority 0), others get priority 1
-            priority = 0 if entry.is_default_entry() else 1
-            hostname = (entry.hostnames[0] if entry.hostnames else "").lower()
-            return (priority, hostname)
+        # Separate default and non-default entries
+        default_entries = [entry for entry in self.entries if entry.is_default_entry()]
+        non_default_entries = [entry for entry in self.entries if not entry.is_default_entry()]
         
-        self.entries.sort(key=sort_key, reverse=not ascending)
+        def hostname_sort_key(entry):
+            hostname = (entry.hostnames[0] if entry.hostnames else "").lower()
+            return hostname
+        
+        # Keep default entries in their natural fixed order (don't sort them)
+        # Define the fixed order for default entries
+        default_order = [
+            {"ip": "127.0.0.1", "hostname": "localhost"},
+            {"ip": "255.255.255.255", "hostname": "broadcasthost"},
+            {"ip": "::1", "hostname": "localhost"},
+        ]
+        
+        # Sort default entries according to their fixed order
+        def default_sort_key(entry):
+            for i, default in enumerate(default_order):
+                if (entry.ip_address == default["ip"] and 
+                    entry.hostnames and entry.hostnames[0] == default["hostname"]):
+                    return i
+            return 999  # fallback for any unexpected default entries
+        
+        default_entries.sort(key=default_sort_key)
+        
+        # Sort non-default entries according to the specified direction
+        non_default_entries.sort(key=hostname_sort_key, reverse=not ascending)
+        
+        # Combine: default entries always first, then sorted non-default entries
+        self.entries = default_entries + non_default_entries
 
     def find_entries_by_hostname(self, hostname: str) -> List[int]:
         """