feat(radius): proxy UniFi Endpoint logins to the UDM over VLAN 11

The UDM RADIUS rejects the pod CIDR as an unknown client; it accepts
10.2.11.0/24. FreeRADIUS pods get net1 on VLAN 11 "(11) RADIUS" and the
udm home server moves to 10.2.11.1.

- Talos k8s-{1,2,3}: VLANConfig radius0 (VLAN 11 on uplink), no
  addresses, IPv6 disabled on the host link.
- Cilium bpf.vlanBypass gains 11: radius0 is address-less like ens19, so
  its tagged frames meet the VLAN filter on uplink (#592).
- NAD freeradius-udm: macvlan on radius0, DHCP IPAM requesting only
  subnet-mask (skipDefault), so the lease has no router and net1 holds
  only the connected /24. No sbr: it moves that route into a source
  table, and the unbound proxy socket would then reach the UDM via eth0
  from the pod IP. tuning disables IPv6 on net1 (VLAN 11 sends RAs).
- NAS listeners bound to eth0, so nothing listens on net1.
- CNP freeradius-udm-egress removed: net1 traffic bypasses Cilium.
- Harness: FreeRADIUS interfaces named eth0/net1 explicitly; Docker
  attaches networks in no fixed order, and the eth0 bind exposed it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/radius/dot1x.md

@@ -24,10 +24,33 @@ paths.
 The anonymous outer identity is mandatory for authentik clients: without it
 the login goes to the UDM and fails.
 
-UDM target: home server `udm`, `10.2.47.1` UDP 1812 (the UDM on VLAN 47, same
-address as the BGP peer in `kubernetes/infrastructure/post-crds/cilium-bgp.yaml`),
-shared secret `UDM_RADIUS_SECRET` from OpenBao `apps/radius`. Egress is
-allowed by CNP `freeradius-udm-egress` in `freeradius-cnp.yaml`.
+UDM target: home server `udm`, `10.2.11.1` UDP 1812 (the UDM on VLAN 11,
+UniFi network "(11) RADIUS"), shared secret `UDM_RADIUS_SECRET` from OpenBao
+`apps/radius`. The UDM RADIUS accepts clients from `10.2.11.0/24` only, not
+from the pod CIDR.
+
+### Path to the UDM
+
+Each FreeRADIUS pod has a second interface `net1` on VLAN 11
+(NetworkAttachmentDefinition `freeradius-udm`,
+`kubernetes/apps/authentik/freeradius-network-attachment.yaml`):
+
+- macvlan on the node link `radius0` (VLAN 11 on `uplink`, no host addresses;
+  VLANConfig in `kubernetes/talos/patches/k8s-{1,2,3}.yaml`). VLAN 11 is in
+  Cilium's `bpf.vlanBypass`, otherwise the tagged frames are dropped on
+  `uplink`.
+- IPv4 leased from the UDM DHCP server (cni-dhcp-daemon), requested without
+  the routers option: `net1` holds only the connected `10.2.11.0/24`, no
+  default route. The proxy socket is not bound to an address; the kernel's
+  route lookup for `10.2.11.1` picks `net1` and its leased address as source.
+- IPv6 disabled on `net1` (VLAN 11 sends router advertisements).
+- The NAS listeners are bound to `eth0` (`interface = eth0`); nothing listens
+  on `net1`.
+- Traffic on `net1` bypasses Cilium; there is no CNP for the UDM hop.
+
+`radius0` must exist on every node before FreeRADIUS pods are scheduled
+there: without it the macvlan ADD fails and the pod stays in
+`ContainerCreating`.
 
 ## authentik objects
 

kubernetes/apps/authentik/freeradius-cnp.yaml

@@ -23,26 +23,6 @@ spec:
             - port: "1813"
               protocol: UDP
 ---
-# FreeRADIUS proxies UniFi Endpoint logins to the UDM RADIUS on VLAN 47.
-# 10.2.47.1 is also the UDM BGP peer in
-# kubernetes/infrastructure/post-crds/cilium-bgp.yaml.
-apiVersion: cilium.io/v2
-kind: CiliumNetworkPolicy
-metadata:
-  name: freeradius-udm-egress
-  namespace: authentik
-spec:
-  endpointSelector:
-    matchLabels:
-      app.kubernetes.io/name: freeradius
-  egress:
-    - toCIDR:
-        - 10.2.47.1/32
-      toPorts:
-        - ports:
-            - port: "1812"
-              protocol: UDP
----
 # FreeRADIUS proxies inner PAP to the 802.1X outpost on its container port.
 # Additive: default-deny-ingress already admits the whole namespace.
 apiVersion: cilium.io/v2

kubernetes/apps/authentik/freeradius-config.yaml

@@ -156,11 +156,12 @@ data:
     }
 
     # UDM RADIUS (FreeRADIUS) for UniFi Endpoint accounts; gets the whole
-    # outer EAP conversation. Address: UDM on VLAN 47, also the BGP peer in
-    # kubernetes/infrastructure/post-crds/cilium-bgp.yaml.
+    # outer EAP conversation. Address: UDM on VLAN 11 "(11) RADIUS", reached
+    # over net1 (freeradius-network-attachment.yaml); the UDM accepts
+    # RADIUS clients from 10.2.11.0/24 only.
     home_server udm {
       type = auth
-      ipaddr = 10.2.47.1
+      ipaddr = 10.2.11.1
       port = 1812
       proto = udp
       secret = $ENV{UDM_RADIUS_SECRET}
@@ -232,28 +233,34 @@ data:
 
   sites-enabled_default: |
     server default {
+      # NAS listeners on eth0 only; net1 (VLAN 11) carries the UDM proxy
+      # traffic and nothing else.
       listen {
         type = auth
         ipaddr = *
         port = 1812
+        interface = eth0
       }
 
       listen {
         type = acct
         ipaddr = *
         port = 1813
+        interface = eth0
       }
 
       listen {
         type = auth
         ipv6addr = ::
         port = 1812
+        interface = eth0
       }
 
       listen {
         type = acct
         ipv6addr = ::
         port = 1813
+        interface = eth0
       }
 
       authorize {

kubernetes/apps/authentik/freeradius-network-attachment.yaml

@@ -0,0 +1,48 @@
+---
+# FreeRADIUS net1: macvlan on radius0, VLAN 11 "(11) RADIUS" (VLANConfig in
+# kubernetes/talos/patches/k8s-{1,2,3}.yaml). Carries only the proxy traffic
+# to home server `udm` (freeradius-config.yaml): the UDM RADIUS accepts
+# clients from 10.2.11.0/24, not from the pod CIDR. Bypasses Cilium policy.
+# Address leased from the UDM; nothing references it.
+#
+# net1 holds only its connected /24, so the unbound proxy socket reaches the
+# UDM via net1 with the leased source. No sbr: it moves that route into a
+# source-based table, and the proxy would leave via eth0 from the pod IP.
+# skipDefault + subnet-mask: the lease is requested without routers, so no
+# default route lands on net1 (dnsmasq sends only requested options).
+# IPv6 off on net1: VLAN 11 sends RAs (default route, SLAAC); the UDM
+# RADIUS clients are IPv4 only.
+#
+# Requires cni-dhcp-daemon (infrastructure/multus) and VLAN 11 in Cilium's
+# bpf.vlanBypass (infrastructure/cilium/helmrelease.yaml).
+apiVersion: k8s.cni.cncf.io/v1
+kind: NetworkAttachmentDefinition
+metadata:
+  name: freeradius-udm
+  namespace: authentik
+spec:
+  config: |
+    {
+      "cniVersion": "0.3.1",
+      "name": "freeradius-udm",
+      "plugins": [
+        {
+          "type": "macvlan",
+          "master": "radius0",
+          "mode": "bridge",
+          "ipam": {
+            "type": "dhcp",
+            "request": [
+              { "skipDefault": true },
+              { "option": "subnet-mask" }
+            ]
+          }
+        },
+        {
+          "type": "tuning",
+          "sysctl": {
+            "net.ipv6.conf.IFNAME.disable_ipv6": "1"
+          }
+        }
+      ]
+    }

kubernetes/apps/authentik/freeradius.yaml

@@ -18,6 +18,9 @@ spec:
     metadata:
       labels:
         app.kubernetes.io/name: freeradius
+      annotations:
+        # net1 on VLAN 11: the path to the UDM RADIUS.
+        k8s.v1.cni.cncf.io/networks: freeradius-udm
     spec:
       enableServiceLinks: false
       affinity:

kubernetes/apps/authentik/kustomization.yaml

@@ -13,6 +13,7 @@ resources:
   - radius-cert.yaml
   - radius-externalsecret.yaml
   - freeradius-config.yaml
+  - freeradius-network-attachment.yaml
   - freeradius.yaml
   - freeradius-cnp.yaml
   # ak-pg CNPG Postgres backend (moved here from the retired seed-authentik KS;

kubernetes/infrastructure/cilium/helmrelease.yaml

@@ -95,19 +95,20 @@ spec:
       # VLAN-tagged frames, accounted as "VLAN traffic disallowed by VLAN
       # filter" in cilium_drop_count_total.
       #
-      # Only VLAN 30 (v30iot) needs listing. Cilium attaches to devices that
-      # carry an address, so it sees mgmt0's frames already untagged by the
-      # 8021q layer — nothing for a VLAN filter to match. ens19 is deliberately
-      # address-less, so its frames only meet the filter on the shared parent,
-      # still tagged. Adding 40 would change nothing and would touch the
-      # datapath carrying etcd and the API.
+      # Only the address-less macvlan parents need listing: VLAN 30 (ens19,
+      # v30iot) and VLAN 11 (radius0, freeradius-udm). Cilium attaches to
+      # devices that carry an address, so it sees mgmt0's frames already
+      # untagged by the 8021q layer — nothing for a VLAN filter to match.
+      # ens19 and radius0 are deliberately address-less, so their frames only
+      # meet the filter on the shared parent, still tagged. Adding 40 would
+      # change nothing and would touch the datapath carrying etcd and the API.
       #
       # The symptom when this is wrong is not a DHCP timeout: a tc-layer drop
       # reaches an AF_PACKET sender as ENOBUFS, so the CNI dhcp plugin reports
       # "no buffer space available" (#592).
       #
       # Same three-copy problem as policyMapMax above. Takes an agent restart.
-      vlanBypass: [30]
+      vlanBypass: [30, 11]
       # Let pods reach the cluster's own LoadBalancer external IPs; Cilium
       # redirects the socket directly to the backend pod instead of sending
       # traffic out to the VIP and back (which fails with L2 announcements).

kubernetes/talos/patches/k8s-1.yaml

@@ -8,6 +8,10 @@ machine:
     # 10.2.30.0/24 route makes node replies bypass the UDM and breaks every
     # DNATed flow.
     net.ipv6.conf.ens19.disable_ipv6: "1"
+    # radius0 (VLAN 11) is LINK ONLY as well: the macvlan parent for the
+    # FreeRADIUS attachment. VLAN 11 announces RAs; the node must not
+    # autoconfigure from them.
+    net.ipv6.conf.radius0.disable_ipv6: "1"
     # These two sit on the untagged fallback network, where nothing may run.
     # Left enabled they autoconfigure a ULA and an IPv6 default route from its
     # RAs, which ties with mgmt0's and costs the cluster IPv6 egress.
@@ -168,6 +172,17 @@ vlanID: 30
 parent: uplink
 up: true
 ---
+# VLAN 11, UniFi "(11) RADIUS": link only, no addresses, no DHCP. Macvlan
+# parent of the freeradius-udm attachment
+# (kubernetes/apps/authentik/freeradius-network-attachment.yaml), which names
+# it as `master`; renaming this link means editing that too.
+apiVersion: v1alpha1
+kind: VLANConfig
+name: radius0
+vlanID: 11
+parent: uplink
+up: true
+---
 # Pod network, VLAN 48. Node-to-node only: the VXLAN overlay rides it once the
 # kubelet node IP moves here, and nothing on it is routed off the switch.
 #

kubernetes/talos/patches/k8s-2.yaml

@@ -7,6 +7,8 @@ machine:
     # macvlan parent for the v30iot pod attachments; host addresses on that L2
     # make node replies bypass the UDM and break every UDM-DNATed flow.
     net.ipv6.conf.ens19.disable_ipv6: "1"
+    # radius0 (VLAN 11): link only — see k8s-1.yaml.
+    net.ipv6.conf.radius0.disable_ipv6: "1"
     # Same for the physical ports on the untagged fallback network: left
     # enabled they take an IPv6 default route from its RAs and cost the
     # cluster IPv6 egress.
@@ -115,6 +117,14 @@ vlanID: 30
 parent: uplink
 up: true
 ---
+# VLAN 11, "(11) RADIUS": link only, no host addressing — see k8s-1.yaml.
+apiVersion: v1alpha1
+kind: VLANConfig
+name: radius0
+vlanID: 11
+parent: uplink
+up: true
+---
 # Pod network, VLAN 48. Node-to-node only, statically addressed, no gateway
 # and no DHCP — see k8s-1.yaml.
 apiVersion: v1alpha1

kubernetes/talos/patches/k8s-3.yaml

@@ -4,6 +4,8 @@ machine:
   sysctls:
     # v30iot NIC carries no host addressing — see k8s-1.yaml.
     net.ipv6.conf.ens19.disable_ipv6: "1"
+    # radius0 (VLAN 11): link only — see k8s-1.yaml.
+    net.ipv6.conf.radius0.disable_ipv6: "1"
     # Same for the physical ports on the untagged fallback network — see
     # k8s-1.yaml.
     net.ipv6.conf.uplink.disable_ipv6: "1"
@@ -102,6 +104,14 @@ vlanID: 30
 parent: uplink
 up: true
 ---
+# VLAN 11, "(11) RADIUS": link only, no host addressing — see k8s-1.yaml.
+apiVersion: v1alpha1
+kind: VLANConfig
+name: radius0
+vlanID: 11
+parent: uplink
+up: true
+---
 # Pod network, VLAN 48. Node-to-node only, statically addressed, no gateway
 # and no DHCP — see k8s-1.yaml.
 apiVersion: v1alpha1

tests/radius/README.md

@@ -31,8 +31,11 @@ Pieces:
 - `mock_outpost.py`: stand-in outpost on UDP 1812, reachable under the
   outpost Service FQDN through a Docker network alias.
 - `mock_udm.py`: stand-in UDM RADIUS at the `udm` home server address from
-  `proxy.conf`, on a second internal bridge `radtest-udm` (that address's
-  /24, no host address). Answers round 1 with Challenge + `State` +
+  `proxy.conf` (`10.2.11.1`), on a second internal bridge `radtest-udm` (that
+  address's /24, no host address). FreeRADIUS gets a second interface there,
+  as `net1` in the pod: only the connected /24, no default route, and the
+  proxy socket picks it by route lookup. The macvlan/DHCP attachment itself
+  is not tested. Answers round 1 with Challenge + `State` +
   EAP-TTLS Start (or Reject for `endpoint-reject`), round 2 with Accept +
   EAP-Success; terminates no EAP.
 - `eapol.Dockerfile`: `eapol_test` from Debian `eapoltest`.

tests/radius/run.sh

@@ -183,14 +183,14 @@ start() {
 
   # Same restrictions as the pod.
   mount_opts freeradius
-  local run_opts=(--network "$net" "${pod_opts[@]}" "${secret_env[@]}" "${mounts[@]}")
+  local run_opts=("${pod_opts[@]}" "${secret_env[@]}" "${mounts[@]}")
   local confdir="" i
   for i in "${!args[@]}"; do
     if [[ "${args[$i]}" == -d ]]; then confdir="${args[$((i + 1))]}"; fi
   done
 
   echo "--- radiusd -XC (config check)"
-  if docker run --rm "${run_opts[@]}" "$image" radiusd -XC -d "$confdir" >"$work/configcheck.log" 2>&1 \
+  if docker run --rm --network "$net" "${run_opts[@]}" "$image" radiusd -XC -d "$confdir" >"$work/configcheck.log" 2>&1 \
     && grep -q "Configuration appears to be OK" "$work/configcheck.log"; then
     pass "radiusd -XC: Configuration appears to be OK"
   else
@@ -199,8 +199,12 @@ start() {
     exit 1
   fi
 
-  docker create --name radtest-freeradius --ip "$ip_radius" --ip6 "$ip6_radius" "${run_opts[@]}" "$image" "${args[@]}" >/dev/null
-  docker network connect "$net_udm" radtest-freeradius
+  # Interface names as in the pod: eth0 the NAS side (the listeners bind to
+  # it), net1 the UDM side. Docker attaches networks in no fixed order.
+  docker create --name radtest-freeradius "${run_opts[@]}" \
+    --network "name=$net,ip=$ip_radius,ip6=$ip6_radius,driver-opt=com.docker.network.endpoint.ifname=eth0" \
+    "$image" "${args[@]}" >/dev/null
+  docker network connect --driver-opt com.docker.network.endpoint.ifname=net1 "$net_udm" radtest-freeradius
   docker start radtest-freeradius >/dev/null
   sleep 2
   if [[ "$(docker inspect -f '{{.State.Running}}' radtest-freeradius)" != true ]]; then