diff --git a/hosts/router/101-net-uplink-a.nix b/hosts/router/101-net-uplink-a.nix
index 3db16c0..3504b17 100644
--- a/hosts/router/101-net-uplink-a.nix
+++ b/hosts/router/101-net-uplink-a.nix
@@ -5,6 +5,7 @@
     id = 101;
     interface = "ens18";
   };
+  networking.interfaces."net-uplink-a".mtu = 1600;
 
   networking.vlans."net-uplink-a.7" = {
     id = 7;
diff --git a/hosts/router/102-net-uplink-b.nix b/hosts/router/102-net-uplink-b.nix
index 7fd4a93..018707d 100644
--- a/hosts/router/102-net-uplink-b.nix
+++ b/hosts/router/102-net-uplink-b.nix
@@ -5,6 +5,7 @@
     id = 102;
     interface = "ens18";
   };
+  networking.interfaces."net-uplink-a".mtu = 1600;
 
   networking.vlans."net-uplink-b.7" = {
     id = 7;
diff --git a/hosts/router/configuration.nix b/hosts/router/configuration.nix
index 5181ec8..ebcbb7b 100644
--- a/hosts/router/configuration.nix
+++ b/hosts/router/configuration.nix
@@ -86,6 +86,8 @@
 
   clerie.forward-filter.enable = true;
 
+  networking.interfaces."ens18".mtu = 9000;
+
   services.pppd.enable = true;
 
   # This value determines the NixOS release from which the default