diff --git a/plugins/services/ipmi.go b/plugins/services/ipmi.go
index f80b92d..1c193dd 100644
--- a/plugins/services/ipmi.go
+++ b/plugins/services/ipmi.go
@@ -4,7 +4,6 @@ package services
 
 import (
 	"context"
-	"encoding/binary"
 	"fmt"
 	"time"
 
@@ -161,5 +160,4 @@ func init() {
 	RegisterUDPPluginWithPorts("ipmi", func() Plugin {
 		return NewIPMIPlugin()
 	}, []int{623})
-	_ = binary.BigEndian // suppress unused import if needed
 }
diff --git a/plugins/services/jdwp.go b/plugins/services/jdwp.go
index ca6f624..d8ac214 100644
--- a/plugins/services/jdwp.go
+++ b/plugins/services/jdwp.go
@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"time"
 
 	"github.com/shadow1ng/fscan/common"
@@ -41,8 +42,7 @@ func (p *JDWPPlugin) Scan(ctx context.Context, info *common.HostInfo, session *c
 	}
 
 	buf := make([]byte, len(jdwpHandshake))
-	n, err := conn.Read(buf)
-	if err != nil || !bytes.Equal(buf[:n], jdwpHandshake) {
+	if _, err := io.ReadFull(conn, buf); err != nil || !bytes.Equal(buf, jdwpHandshake) {
 		return &ScanResult{Success: false, Service: "jdwp"}
 	}
 
diff --git a/plugins/services/nfs.go b/plugins/services/nfs.go
index c147a2b..74a81c6 100644
--- a/plugins/services/nfs.go
+++ b/plugins/services/nfs.go
@@ -36,9 +36,15 @@ func (p *NFSPlugin) Scan(ctx context.Context, info *common.HostInfo, session *co
 
 	// NFS NULL call (program=100003, version=3, procedure=0) to confirm NFS service
 	if err := p.rpcNullCall(conn, 100003, 3); err != nil {
-		// Try v4
-		_ = conn.SetDeadline(time.Now().Add(timeout))
-		if err := p.rpcNullCall(conn, 100003, 4); err != nil {
+		// Try v4 on a fresh connection
+		conn.Close()
+		c, dialErr := session.DialTCP(ctx, "tcp", addr, timeout)
+		if dialErr != nil {
+			return &ScanResult{Success: false, Service: "nfs"}
+		}
+		defer c.Close()
+		_ = c.SetDeadline(time.Now().Add(timeout))
+		if err := p.rpcNullCall(c, 100003, 4); err != nil {
 			return &ScanResult{Success: false, Service: "nfs"}
 		}
 	}
diff --git a/plugins/services/rmi.go b/plugins/services/rmi.go
index b7110ba..05ea106 100644
--- a/plugins/services/rmi.go
+++ b/plugins/services/rmi.go
@@ -5,6 +5,7 @@ package services
 import (
 	"context"
 	"fmt"
+	"io"
 	"time"
 
 	"github.com/shadow1ng/fscan/common"
@@ -40,18 +41,23 @@ func (p *RMIPlugin) Scan(ctx context.Context, info *common.HostInfo, session *co
 		return &ScanResult{Success: false, Service: "rmi"}
 	}
 
-	buf := make([]byte, 256)
+	// RMI server responds with ProtocolAck (0x4e) followed by endpoint info.
+	// Read at least 1 byte for the ack; io.ReadFull guarantees it.
+	ack := make([]byte, 1)
+	if _, err := io.ReadFull(conn, ack); err != nil {
+		return &ScanResult{Success: false, Service: "rmi"}
+	}
+	if ack[0] != 0x4e {
+		return &ScanResult{Success: false, Service: "rmi"}
+	}
+
+	buf := make([]byte, 255)
 	n, err := conn.Read(buf)
-	if err != nil || n < 5 {
+	if err != nil && n == 0 {
 		return &ScanResult{Success: false, Service: "rmi"}
 	}
 
-	// RMI server responds with 0x4e (ProtocolAck) followed by endpoint info
-	if buf[0] != 0x4e {
-		return &ScanResult{Success: false, Service: "rmi"}
-	}
-
-	endpoint := parseRMIEndpoint(buf[1:n])
+	endpoint := parseRMIEndpoint(buf[:n])
 
 	return &ScanResult{
 		Success: true,
diff --git a/plugins/services/snmp.go b/plugins/services/snmp.go
index 954227b..cea4b94 100644
--- a/plugins/services/snmp.go
+++ b/plugins/services/snmp.go
@@ -23,7 +23,7 @@ func NewSNMPPlugin() *SNMPPlugin {
 
 func (p *SNMPPlugin) Scan(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
 	config := session.Config
-	timeout := time.Duration(config.Timeout.Seconds()) * time.Second
+	timeout := config.Timeout
 	if timeout <= 0 {
 		timeout = 3 * time.Second
 	}