flake.lock

@@ -288,11 +288,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1726937504,
+        "lastModified": 1726755586,
-        "narHash": "sha256-bvGoiQBvponpZh8ClUcmJ6QnsNKw0EMrCQJARK3bI1c=",
+        "narHash": "sha256-PmUr/2GQGvFTIJ6/Tvsins7Q43KTMvMFhvG6oaYK+Wk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9357f4f23713673f310988025d9dc261c20e70c6",
+        "rev": "c04d5652cfa9742b1d519688f65d1bbccea9eb7e",
         "type": "github"
       },
       "original": {

hosts/carbon/ppp.nix

@@ -54,7 +54,31 @@
   };
 
   clerie.firewall.extraForwardMangleCommands = ''
-    ip46tables -t mangle -A forward-mangle -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
+    ip46tables -t mangle -A forward-mangle -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1416
   '';
 
+  networking.dhcpcd-prefixdelegation = {
+    enable = true;
+    interfaces = {
+      "ppp-dtagdsl" = {
+        iaid = 1;
+        interfaces = {
+          "net-heimnetz" = {
+            sla_id = 201;
+            prefix_len = 64;
+          };
+        };
+      };
+    };
+  };
+
+  environment.etc."ppp/ipv6-up" = {
+    text = ''
+      #!${pkgs.runtimeShell}
+
+      set -euo pipefail
+
+      ${pkgs.dhcpcd}/bin/dhcpcd --renew $1
+    '';
+  };
 }