diff --git a/flake.lock b/flake.lock
index 9168b60..c84a65a 100644
--- a/flake.lock
+++ b/flake.lock
@@ -288,11 +288,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1726755586,
-        "narHash": "sha256-PmUr/2GQGvFTIJ6/Tvsins7Q43KTMvMFhvG6oaYK+Wk=",
+        "lastModified": 1726937504,
+        "narHash": "sha256-bvGoiQBvponpZh8ClUcmJ6QnsNKw0EMrCQJARK3bI1c=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "c04d5652cfa9742b1d519688f65d1bbccea9eb7e",
+        "rev": "9357f4f23713673f310988025d9dc261c20e70c6",
         "type": "github"
       },
       "original": {
diff --git a/hosts/carbon/ppp.nix b/hosts/carbon/ppp.nix
index 77e6270..784c1de 100644
--- a/hosts/carbon/ppp.nix
+++ b/hosts/carbon/ppp.nix
@@ -54,31 +54,7 @@
   };
 
   clerie.firewall.extraForwardMangleCommands = ''
-    ip46tables -t mangle -A forward-mangle -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1416
+    ip46tables -t mangle -A forward-mangle -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
   '';
 
-  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
-    '';
-  };
 }