fix ipv6

configuration.nix

@@ -215,7 +215,7 @@
     hostId = "0f712d56";
     firewall.enable = true;
     useDHCP = false;
-    enableIPv6 = false;
+    # enableIPv6 = false;
 
     interfaces.${eth_interface} = {
       ipv4.addresses = [
@@ -226,7 +226,7 @@
       ];
       ipv6.addresses = [
         {
-          address = "2603:9001:3900:f005:1779:17ed:4698:6259";
+          address = "fe80::9e6b:ff:fe4d:abb";
           prefixLength = 64;
         }
       ];
@@ -235,6 +235,10 @@
       address = "10.1.1.1";
       interface = eth_interface;
     };
+    defaultGateway6 = {
+      address = "fe80::/64";
+      interface = eth_interface;
+    };
   };
 
   users.users.${username} = {