docs: update Phase 1/6 status — multi-NIC + virtual devices

local/docs/NETWORKING-IMPROVEMENT-PLAN.md

@@ -316,6 +316,14 @@ Network-critical components (relibc, kernel, base) have all required commits pre
 
 ### Phase 1: Multi-NIC and Driver Feature Surface
 
+**Status: 🟡 PARTIALLY COMPLETE (updated 2026-07-09)**
+
+`Smolnetd::new()` now accepts `Vec<(Fd, EthernetAddress, String)>` —
+multiple Ethernet adapters with MAC addresses. The single-NIC FIXME
+in main.rs has been removed (R59).
+
+**Original plan below:**
+
 **Goal:** Remove the single-NIC FIXME and give the stack visibility into driver capabilities.
 
 **Duration:** 3–4 weeks.
@@ -689,12 +697,27 @@ validate the stack on real NICs.
 
 ### Phase 6: Forwarding, Virtual Devices, and Advanced Features
 
+**Status: 🟡 IN PROGRESS (updated 2026-07-09)**
+
 **Virtual devices status (2026-07-09):**
 - VLAN: ✅ Parent device integration (R63), tagged frames forwarded to parent.
-- Bridge: ✅ MAC learning, aging, STP BPDU handling.
-- TUN: ✅ Scheme interface, event loop wired (R2).
-- VXLAN/GRE/IPIP: Implemented as device types, not yet functional (require
-  parent device integration — same pattern as VLAN R63 fix).
+- Bridge: ✅ MAC learning, aging, STP BPDU handling, 5 unit tests
+- TUN: ✅ Scheme interface, event loop wired (R2)
+- VXLAN: ✅ Encapsulation/decapsulation, parent forwarding (R64)
+- GRE: ✅ Encapsulation/decapsulation with key, parent forwarding (R64)
+- IPIP: ✅ IP-in-IP tunnel, parent forwarding (R64)
+- Bond: ✅ Round-robin slave forwarding with statistics
+
+**Remaining VM work:**
+- VXLAN/GRE/IPIP inbound RX wiring: decapsulated packets need to be
+  re-injected into the parent's RX path (requires `DeviceList` integration
+  at the recv path, currently works only through external `push_received()`)
+
+**Forwarding status:**
+- IPv4 forwarding: ✅ through `forward_packets()`
+- IPv6 forwarding: ⚠️ `forward_packets` only processes IPv4; IPv6 skips
+  to local delivery
+- IP forwarding toggle: ✅ `sysctl/net/ipv4/ip_forward`
 
 **Original plan below:**