diff --git a/bin/usb-client b/bin/usb-client
index e096a5a..41d28ae 100755
Binary files a/bin/usb-client and b/bin/usb-client differ
diff --git a/bin/usb-client.exe b/bin/usb-client.exe
index 1badc81..cfa0759 100755
Binary files a/bin/usb-client.exe and b/bin/usb-client.exe differ
diff --git a/bin/usb-relay b/bin/usb-relay
index fbe145f..7bbbd7e 100755
Binary files a/bin/usb-relay and b/bin/usb-relay differ
diff --git a/internal/usb/usbdevfs.go b/internal/usb/usbdevfs.go
index 7d4c45d..fe001aa 100644
--- a/internal/usb/usbdevfs.go
+++ b/internal/usb/usbdevfs.go
@@ -37,6 +37,7 @@ var (
 	usbdevfsSetInterface     = ior('U', 4, unsafe.Sizeof(usbdevfsSetIntf{}))
 	usbdevfsSetConfig        = ior('U', 5, 4)
 	usbdevfsSubmitURB        = ior('U', 10, unsafe.Sizeof(usbdevfsURB{}))
+	usbdevfsResetEP          = ior('U', 3, 4)
 	usbdevfsDiscardURB       = io_('U', 11)
 	usbdevfsReapURB          = iow('U', 12, unsafe.Sizeof(uintptr(0)))
 	usbdevfsReapURBNDelay    = iow('U', 13, unsafe.Sizeof(uintptr(0)))
@@ -348,6 +349,27 @@ func (h *DeviceHandle) DiscardURB(urb *usbdevfsURB) error {
 	return nil
 }
 
+// DiscardURBByPtr cancels a submitted URB given its raw pointer.
+// Use this when the URB type is not accessible (e.g. from another package).
+func (h *DeviceHandle) DiscardURBByPtr(ptr unsafe.Pointer) error {
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(h.fd), usbdevfsDiscardURB, uintptr(ptr))
+	if errno != 0 {
+		return fmt.Errorf("USBDEVFS_DISCARDURB: %w", errno)
+	}
+	return nil
+}
+
+// ResetEndpoint resets the host-side data toggle for an endpoint without
+// sending any USB traffic to the device. Use after SET_CONFIGURATION to
+// sync host controller toggle state with the device.
+func (h *DeviceHandle) ResetEndpoint(endpoint uint32) error {
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(h.fd), usbdevfsResetEP, uintptr(unsafe.Pointer(&endpoint)))
+	if errno != 0 {
+		return fmt.Errorf("USBDEVFS_RESETEP(%d): %w", endpoint, errno)
+	}
+	return nil
+}
+
 // SubmitISOURBParams holds parameters for async ISO URB submission
 type SubmitISOURBParams struct {
 	Endpoint        uint8
diff --git a/internal/usbip/server.go b/internal/usbip/server.go
index e06d593..cf9cdcb 100644
--- a/internal/usbip/server.go
+++ b/internal/usbip/server.go
@@ -15,7 +15,6 @@ import (
 	"unsafe"
 
 	"github.com/duffy/usb-server/internal/usb"
-	"golang.org/x/sys/unix"
 )
 
 // Server handles USB/IP protocol on the share side.
@@ -112,9 +111,7 @@ func (s *Server) Detach() {
 	s.mu.Lock()
 	for seqNum, pending := range s.pendingURBs {
 		if pending.urbPtr != nil {
-			unix.Syscall(unix.SYS_IOCTL, uintptr(s.handle.Fd()),
-				0x8000550B, // USBDEVFS_DISCARDURB
-				uintptr(pending.urbPtr))
+			s.handle.DiscardURBByPtr(pending.urbPtr)
 		}
 		delete(s.pendingURBs, seqNum)
 	}
@@ -410,6 +407,33 @@ func (s *Server) handleCmdSubmit(r io.Reader, hdr *URBHeader, retChan chan<- []b
 				status = -32
 			}
 
+		case bmRequestType == 0x00 && bRequest == 0x09:
+			// SET_CONFIGURATION — the device resets all endpoint data toggles
+			// to DATA0 on SET_CONFIGURATION, but USBDEVFS_CONTROL doesn't update
+			// the host controller's toggle state. We must manually reset host-side
+			// toggles via USBDEVFS_RESETEP, otherwise data toggle mismatch causes
+			// all non-control transfers (bulk, interrupt) to fail silently.
+			buf := transferBuf
+			if buf == nil {
+				buf = make([]byte, 0)
+			}
+			_, err := s.handle.ControlTransfer(bmRequestType, bRequest, wValue, wIndex, 0, 5000, buf)
+			if err != nil {
+				log.Printf("[usbip-server] SET_CONFIGURATION(%d) failed: %v", wValue, err)
+				status = -32
+			} else {
+				log.Printf("[usbip-server] SET_CONFIGURATION(%d) OK, resetting endpoint toggles", wValue)
+				for epNum := range s.epTypes {
+					if epNum == 0 {
+						continue
+					}
+					// Reset both OUT and IN directions; ignore errors for
+					// non-existent directions (e.g. endpoint only has IN)
+					s.handle.ResetEndpoint(uint32(epNum))
+					s.handle.ResetEndpoint(uint32(epNum) | 0x80)
+				}
+			}
+
 		default:
 			// Generic OUT control transfer
 			buf := transferBuf
@@ -577,11 +601,7 @@ func (s *Server) handleCmdUnlink(r io.Reader, hdr *URBHeader, retChan chan<- []b
 
 	var status int32
 	if exists && pending.urbPtr != nil {
-		// Try to discard the URB via proper ioctl
-		_, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(s.handle.Fd()),
-			uintptr(0x8000550B), // USBDEVFS_DISCARDURB
-			uintptr(pending.urbPtr))
-		if errno == 0 {
+		if err := s.handle.DiscardURBByPtr(pending.urbPtr); err == nil {
 			status = -104 // -ECONNRESET
 		}
 	}