diff --git a/errors.go b/errors.go
index f360850..1dabc8e 100644
--- a/errors.go
+++ b/errors.go
@@ -12,6 +12,8 @@ const (
 	ErrorTypeNew             = "new"
 	ErrorTypeUnreachable     = "unreachable"
 	ErrorTypeHighUtilization = "high_utilization"
+	ErrorTypePortFlap        = "port_flap"
+	ErrorTypePortDown        = "port_down"
 )
 
 type Error struct {
@@ -139,6 +141,58 @@ func (e *ErrorTracker) AddUtilizationError(node *Node, portName string, utilizat
 	e.t.NotifyUpdate()
 }
 
+func (e *ErrorTracker) AddPortFlap(node *Node, portName string) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	key := "flap:" + node.ID + ":" + portName
+	now := time.Now()
+
+	if existing, ok := e.errors[key]; ok {
+		existing.LastUpdated = now
+		e.t.NotifyUpdate()
+		return
+	}
+
+	e.nextID++
+	e.errors[key] = &Error{
+		ID:          fmt.Sprintf("err-%d", e.nextID),
+		NodeID:      node.ID,
+		NodeName:    node.DisplayName(),
+		Port:        portName,
+		Type:        ErrorTypePortFlap,
+		FirstSeen:   now,
+		LastUpdated: now,
+	}
+	e.t.NotifyUpdate()
+}
+
+func (e *ErrorTracker) AddPortDown(node *Node, portName string) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	key := "down:" + node.ID + ":" + portName
+	now := time.Now()
+
+	if existing, ok := e.errors[key]; ok {
+		existing.LastUpdated = now
+		e.t.NotifyUpdate()
+		return
+	}
+
+	e.nextID++
+	e.errors[key] = &Error{
+		ID:          fmt.Sprintf("err-%d", e.nextID),
+		NodeID:      node.ID,
+		NodeName:    node.DisplayName(),
+		Port:        portName,
+		Type:        ErrorTypePortDown,
+		FirstSeen:   now,
+		LastUpdated: now,
+	}
+	e.t.NotifyUpdate()
+}
+
 func (e *ErrorTracker) ClearError(errorID string) {
 	e.mu.Lock()
 	defer e.mu.Unlock()
diff --git a/nodes.go b/nodes.go
index d7d0282..d9c0125 100644
--- a/nodes.go
+++ b/nodes.go
@@ -246,7 +246,7 @@ func (n *Nodes) startNodePoller(node *Node) {
 
 	go func() {
 		pollTicker := time.NewTicker(10 * time.Second)
-		pingTicker := time.NewTicker(5 * time.Second)
+		pingTicker := time.NewTicker(3 * time.Second)
 		defer pollTicker.Stop()
 		defer pingTicker.Stop()
 
diff --git a/ping.go b/ping.go
index 9c52025..e6b8b44 100644
--- a/ping.go
+++ b/ping.go
@@ -172,7 +172,7 @@ func (t *Tendrils) pingNode(node *Node) {
 
 	anyReachable := false
 	for _, ipStr := range ips {
-		if t.ping.Ping(ipStr, 2*time.Second) {
+		if t.ping.Ping(ipStr, 1*time.Second) {
 			anyReachable = true
 			break
 		}
diff --git a/snmp.go b/snmp.go
index 0bc6313..684f012 100644
--- a/snmp.go
+++ b/snmp.go
@@ -17,6 +17,7 @@ type ifaceCounters struct {
 	outPkts   uint64
 	inBytes   uint64
 	outBytes  uint64
+	uptime    uint64
 	timestamp time.Time
 }
 
@@ -252,9 +253,15 @@ func (t *Tendrils) queryInterfaceStats(snmp *gosnmp.GoSNMP, node *Node, ifNames
 		status, hasStatus := ifOperStatus[ifIndex]
 		isUp := hasStatus && status == 1
 		if !isUp {
+			if iface.Up {
+				log.Printf("[ERROR] port down on %s %s", node.DisplayName(), name)
+				t.errors.AddPortDown(node, name)
+			}
+			iface.Up = false
 			iface.Stats = nil
 			continue
 		}
+		iface.Up = true
 
 		stats := &InterfaceStats{}
 
@@ -282,11 +289,15 @@ func (t *Tendrils) queryInterfaceStats(snmp *gosnmp.GoSNMP, node *Node, ifNames
 		inPkts := ifHCInUcastPkts[ifIndex] + ifHCInMcastPkts[ifIndex] + ifHCInBcastPkts[ifIndex]
 		outPkts := ifHCOutUcastPkts[ifIndex] + ifHCOutMcastPkts[ifIndex] + ifHCOutBcastPkts[ifIndex]
 
-		if hasInBytes && hasOutBytes {
-			key := node.ID + ":" + name
-			ifaceTracker.mu.Lock()
-			prev, hasPrev := ifaceTracker.counters[key]
-			if hasPrev {
+		key := node.ID + ":" + name
+		ifaceTracker.mu.Lock()
+		prev, hasPrev := ifaceTracker.counters[key]
+		if hasPrev {
+			if prev.uptime > 0 && stats.Uptime > 0 && stats.Uptime < prev.uptime {
+				log.Printf("[ERROR] port flap on %s %s: uptime dropped from %d to %d seconds", node.DisplayName(), name, prev.uptime, stats.Uptime)
+				t.errors.AddPortFlap(node, name)
+			}
+			if hasInBytes && hasOutBytes {
 				elapsed := now.Sub(prev.timestamp).Seconds()
 				if elapsed > 0 {
 					stats.InPktsRate = float64(inPkts-prev.inPkts) / elapsed
@@ -307,15 +318,20 @@ func (t *Tendrils) queryInterfaceStats(snmp *gosnmp.GoSNMP, node *Node, ifNames
 					}
 				}
 			}
-			ifaceTracker.counters[key] = &ifaceCounters{
-				inPkts:    inPkts,
-				outPkts:   outPkts,
-				inBytes:   inBytes,
-				outBytes:  outBytes,
-				timestamp: now,
-			}
-			ifaceTracker.mu.Unlock()
 		}
+		storedUptime := stats.Uptime
+		if storedUptime == 0 && hasPrev {
+			storedUptime = prev.uptime
+		}
+		ifaceTracker.counters[key] = &ifaceCounters{
+			inPkts:    inPkts,
+			outPkts:   outPkts,
+			inBytes:   inBytes,
+			outBytes:  outBytes,
+			uptime:    storedUptime,
+			timestamp: now,
+		}
+		ifaceTracker.mu.Unlock()
 
 		if poe, ok := poeStats[name]; ok {
 			stats.PoE = poe
diff --git a/types.go b/types.go
index 11b4f93..04de840 100644
--- a/types.go
+++ b/types.go
@@ -360,6 +360,7 @@ type Interface struct {
 	Name  string          `json:"name,omitempty"`
 	MAC   MAC             `json:"mac"`
 	IPs   IPSet           `json:"ips,omitempty"`
+	Up    bool            `json:"up,omitempty"`
 	Stats *InterfaceStats `json:"stats,omitempty"`
 }
 
@@ -368,6 +369,7 @@ func (i *Interface) MarshalJSON() ([]byte, error) {
 		Name  string          `json:"name,omitempty"`
 		MAC   MAC             `json:"mac"`
 		IPs   []string        `json:"ips,omitempty"`
+		Up    bool            `json:"up,omitempty"`
 		Stats *InterfaceStats `json:"stats,omitempty"`
 	}
 	var ips []string
@@ -378,6 +380,7 @@ func (i *Interface) MarshalJSON() ([]byte, error) {
 		Name:  i.Name,
 		MAC:   i.MAC,
 		IPs:   ips,
+		Up:    i.Up,
 		Stats: i.Stats,
 	})
 }