add ipv4 dns

configuration.nix

@@ -74,6 +74,8 @@
     nameservers = [
       "2606:4700:4700::1111#one.one.one.one"
       "2620:fe::fe#dns.quad9.net"
+      "1.1.1.1#one.one.one.one"
+      "9.9.9.9#dns.quad9.net"
     ];
     useDHCP = false;
     useNetworkd = true;
@@ -125,10 +127,6 @@
     # Cache DNS lookups to improve performance
     resolved = {
       enable = true;
-      fallbackDns = [
-        "1.1.1.1#one.one.one.one"
-        "9.9.9.9#dns.quad9.net"
-      ];
       dnssec = "allow-downgrade";
       dnsovertls = "true";
       extraConfig = ''
@@ -139,6 +137,7 @@
   };
 
   programs = {
+    mtr.enable = true;
     vim = {
       enable = true;
       defaultEditor = true;

flake.lock

@@ -68,11 +68,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1764677808,
-        "narHash": "sha256-H3lC7knbXOBrHI9hITQ7modLuX20mYJVhZORL5ioms0=",
+        "lastModified": 1766473571,
+        "narHash": "sha256-5G1NDO2PulBx1RoaA6U1YoUDX0qZslpPxv+n5GX6Qto=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1aab89277eb2d87823d5b69bae631a2496cff57a",
+        "rev": "76701a179d3a98b07653e2b0409847499b2a07d3",
         "type": "github"
       },
       "original": {