fix local address population and snmp reverse port discovery

populate root node with local macs/ips at startup, excluding loopback addresses and permanent arp entries. detect when snmp finds parent node mac in child forwarding table and set child localport.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

arp.go

@@ -63,6 +63,11 @@ func (t *Tendrils) parseARPDarwin() []arpEntry {
 	scanner := bufio.NewScanner(strings.NewReader(string(output)))
 	for scanner.Scan() {
 		line := scanner.Text()
+
+		if strings.Contains(line, "permanent") {
+			continue
+		}
+
 		fields := strings.Fields(line)
 		if len(fields) < 6 {
 			continue

nodes.go

@@ -122,6 +122,7 @@ func (n *Nodes) UpdateWithParent(parentIP net.IP, ips []net.IP, macs []net.Hardw
 	node := n.nodes[targetID]
 	var added []string
 
+	if targetID != 0 {
 		if node.LocalPort == "" && childPort != "" {
 			node.LocalPort = childPort
 			added = append(added, "localPort="+childPort)
@@ -131,6 +132,7 @@ func (n *Nodes) UpdateWithParent(parentIP net.IP, ips []net.IP, macs []net.Hardw
 			node.ParentPort = parentPort
 			added = append(added, "parentPort="+parentPort)
 		}
+	}
 
 	for _, ip := range ips {
 		ipKey := ip.String()

snmp.go

@@ -207,6 +207,30 @@ func (t *Tendrils) queryBridgeMIB(snmp *gosnmp.GoSNMP, deviceIP net.IP) {
 		if addToParent {
 			t.nodes.Update([]net.IP{deviceIP}, []net.HardwareAddr{mac}, "", "", "snmp")
 		} else {
+			t.nodes.mu.RLock()
+			deviceNodeID := -1
+			if id, exists := t.nodes.ipIndex[deviceIP.String()]; exists {
+				deviceNodeID = id
+			}
+			macNodeID := -1
+			if id, exists := t.nodes.macIndex[mac.String()]; exists {
+				macNodeID = id
+			}
+
+			if deviceNodeID != -1 && macNodeID != -1 {
+				deviceNode := t.nodes.nodes[deviceNodeID]
+				if deviceNode.ParentID == macNodeID {
+					t.nodes.mu.RUnlock()
+					t.nodes.mu.Lock()
+					if deviceNode.LocalPort == "" {
+						deviceNode.LocalPort = ifName
+					}
+					t.nodes.mu.Unlock()
+					continue
+				}
+			}
+			t.nodes.mu.RUnlock()
+
 			t.nodes.UpdateWithParent(deviceIP, nil, []net.HardwareAddr{mac}, ifName, "", "snmp")
 		}
 	}
@@ -280,6 +304,30 @@ func (t *Tendrils) queryARPTable(snmp *gosnmp.GoSNMP, deviceIP net.IP) {
 				ifName = "??"
 			}
 
+			t.nodes.mu.RLock()
+			deviceNodeID := -1
+			if id, exists := t.nodes.ipIndex[deviceIP.String()]; exists {
+				deviceNodeID = id
+			}
+			macNodeID := -1
+			if id, exists := t.nodes.macIndex[mac.String()]; exists {
+				macNodeID = id
+			}
+
+			if deviceNodeID != -1 && macNodeID != -1 {
+				deviceNode := t.nodes.nodes[deviceNodeID]
+				if deviceNode.ParentID == macNodeID {
+					t.nodes.mu.RUnlock()
+					t.nodes.mu.Lock()
+					if deviceNode.LocalPort == "" {
+						deviceNode.LocalPort = ifName
+					}
+					t.nodes.mu.Unlock()
+					continue
+				}
+			}
+			t.nodes.mu.RUnlock()
+
 			t.nodes.UpdateWithParent(deviceIP, ips, []net.HardwareAddr{mac}, ifName, "", "snmp")
 		}
 	}

tendrils.go

@@ -23,6 +23,8 @@ func (t *Tendrils) Run() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
+	t.populateLocalAddresses()
+
 	go t.pollARP(ctx)
 	go t.pollSNMP(ctx)
 
@@ -36,6 +38,41 @@ func (t *Tendrils) Run() {
 	}
 }
 
+func (t *Tendrils) populateLocalAddresses() {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return
+	}
+
+	t.nodes.mu.Lock()
+	defer t.nodes.mu.Unlock()
+
+	root := t.nodes.nodes[0]
+
+	for _, iface := range interfaces {
+		if len(iface.HardwareAddr) > 0 {
+			macKey := iface.HardwareAddr.String()
+			root.MACs[macKey] = iface.HardwareAddr
+			t.nodes.macIndex[macKey] = 0
+		}
+
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+
+		for _, addr := range addrs {
+			if ipnet, ok := addr.(*net.IPNet); ok {
+				if ipnet.IP.To4() != nil && !ipnet.IP.IsLoopback() {
+					ipKey := ipnet.IP.String()
+					root.IPs[ipKey] = ipnet.IP
+					t.nodes.ipIndex[ipKey] = 0
+				}
+			}
+		}
+	}
+}
+
 func (t *Tendrils) listInterfaces() []net.Interface {
 	interfaces, err := net.Interfaces()
 	if err != nil {