Merge pull request 'fix(shelly-manager): disable TCP black-hole detection in the pod netns' (#1550 ) from shelly-manager-no-mtu-probing into main

Reviewed-on: #1550
fix(shelly-manager): disable TCP black-hole detection in the pod netns
2026-11-02 09:37:08 +00:00 · 2026-11-02 10:36:01 +01:00 · 2026-11-02 07:45:38 +00:00
2 changed files with 6 additions and 2 deletions
@@ -46,7 +46,7 @@ spec:
        k8s.v1.cni.cncf.io/networks: shelly-manager-iot
        # Changing this rolls the pod, which is the only way a change to the
        # shelly-manager-iot attachment takes effect.
-        net.renner.uno/iot-attachment-config: "tuning-no-ra"
+        net.renner.uno/iot-attachment-config: "tuning-no-ra-no-mtu-probing"
    spec:
      # eth0 (Cilium-managed pod network) is still the primary — it
      # carries the ingress, mosquitto LB return path, etc. The macvlan
@@ -50,6 +50,9 @@ spec:
  # to IPv6 clients on v30iot leave via net1, bypassing Cilium's LoadBalancer
  # reverse NAT. tuning turns RA processing off on net1; the link-local
  # address mDNS uses stays.
+  #
+  # tcp_mtu_probing (pod-wide; Cilium sets 1): Shelly flash-write stalls
+  # trip black-hole detection, which cuts firmware downloads to 48-byte MSS.
  config: |
    {
      "cniVersion": "0.3.1",
@@ -67,7 +70,8 @@ spec:
          "type": "tuning",
          "sysctl": {
            "net.ipv6.conf.IFNAME.accept_ra": "0",
-            "net.ipv6.conf.IFNAME.autoconf": "0"
+            "net.ipv6.conf.IFNAME.autoconf": "0",
+            "net.ipv4.tcp_mtu_probing": "0"
          }
        },
        {