diff --git a/go.mod b/go.mod
index ffda816a8..77935d3f2 100644
--- a/go.mod
+++ b/go.mod
@@ -3,8 +3,8 @@ module golang.org/x/net
 go 1.18
 
 require (
-	golang.org/x/crypto v0.27.0
-	golang.org/x/sys v0.25.0
-	golang.org/x/term v0.24.0
-	golang.org/x/text v0.18.0
+	golang.org/x/crypto v0.28.0
+	golang.org/x/sys v0.26.0
+	golang.org/x/term v0.25.0
+	golang.org/x/text v0.19.0
 )
diff --git a/go.sum b/go.sum
index a1a56bf3d..1b8c61d60 100644
--- a/go.sum
+++ b/go.sum
@@ -1,8 +1,8 @@
-golang.org/x/crypto v0.27.0 h1:GXm2NjJrPaiv/h1tb2UH8QfgC/hOf/+z0p6PT8o1w7A=
-golang.org/x/crypto v0.27.0/go.mod h1:1Xngt8kV6Dvbssa53Ziq6Eqn0HqbZi5Z6R0ZpwQzt70=
-golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
-golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.24.0 h1:Mh5cbb+Zk2hqqXNO7S1iTjEphVL+jb8ZWaqh/g+JWkM=
-golang.org/x/term v0.24.0/go.mod h1:lOBK/LVxemqiMij05LGJ0tzNr8xlmwBRJ81PX6wVLH8=
-golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
-golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+golang.org/x/crypto v0.28.0 h1:GBDwsMXVQi34v5CCYUm2jkJvu4cbtru2U4TN2PSyQnw=
+golang.org/x/crypto v0.28.0/go.mod h1:rmgy+3RHxRZMyY0jjAJShp2zgEdOqj2AO7U0pYmeQ7U=
+golang.org/x/sys v0.26.0 h1:KHjCJyddX0LoSTb3J+vWpupP9p0oznkqVk/IfjymZbo=
+golang.org/x/sys v0.26.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.25.0 h1:WtHI/ltw4NvSUig5KARz9h521QvRC8RmF/cuYqifU24=
+golang.org/x/term v0.25.0/go.mod h1:RPyXicDX+6vLxogjjRxjgD2TKtmAO6NZBsBRfrOLu7M=
+golang.org/x/text v0.19.0 h1:kTxAhCbGbxhK0IwgSKiMO5awPoDQ0RpfiVYBfK860YM=
+golang.org/x/text v0.19.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
diff --git a/http2/clientconn_test.go b/http2/clientconn_test.go
index 553379099..92d630514 100644
--- a/http2/clientconn_test.go
+++ b/http2/clientconn_test.go
@@ -148,7 +148,7 @@ func (tc *testClientConn) readClientPreface() {
 	}
 }
 
-func newTestClientConn(t *testing.T, opts ...func(*Transport)) *testClientConn {
+func newTestClientConn(t *testing.T, opts ...any) *testClientConn {
 	t.Helper()
 
 	tt := newTestTransport(t, opts...)
@@ -486,7 +486,7 @@ type testTransport struct {
 	ccs []*testClientConn
 }
 
-func newTestTransport(t *testing.T, opts ...func(*Transport)) *testTransport {
+func newTestTransport(t *testing.T, opts ...any) *testTransport {
 	tt := &testTransport{
 		t:     t,
 		group: newSynctest(time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)),
@@ -495,7 +495,15 @@ func newTestTransport(t *testing.T, opts ...func(*Transport)) *testTransport {
 
 	tr := &Transport{}
 	for _, o := range opts {
-		o(tr)
+		switch o := o.(type) {
+		case func(*http.Transport):
+			if tr.t1 == nil {
+				tr.t1 = &http.Transport{}
+			}
+			o(tr.t1)
+		case func(*Transport):
+			o(tr)
+		}
 	}
 	tt.tr = tr
 
diff --git a/http2/config.go b/http2/config.go
new file mode 100644
index 000000000..de58dfb8d
--- /dev/null
+++ b/http2/config.go
@@ -0,0 +1,122 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import (
+	"math"
+	"net/http"
+	"time"
+)
+
+// http2Config is a package-internal version of net/http.HTTP2Config.
+//
+// http.HTTP2Config was added in Go 1.24.
+// When running with a version of net/http that includes HTTP2Config,
+// we merge the configuration with the fields in Transport or Server
+// to produce an http2Config.
+//
+// Zero valued fields in http2Config are interpreted as in the
+// net/http.HTTPConfig documentation.
+//
+// Precedence order for reconciling configurations is:
+//
+//   - Use the net/http.{Server,Transport}.HTTP2Config value, when non-zero.
+//   - Otherwise use the http2.{Server.Transport} value.
+//   - If the resulting value is zero or out of range, use a default.
+type http2Config struct {
+	MaxConcurrentStreams         uint32
+	MaxDecoderHeaderTableSize    uint32
+	MaxEncoderHeaderTableSize    uint32
+	MaxReadFrameSize             uint32
+	MaxUploadBufferPerConnection int32
+	MaxUploadBufferPerStream     int32
+	SendPingTimeout              time.Duration
+	PingTimeout                  time.Duration
+	WriteByteTimeout             time.Duration
+	PermitProhibitedCipherSuites bool
+	CountError                   func(errType string)
+}
+
+// configFromServer merges configuration settings from
+// net/http.Server.HTTP2Config and http2.Server.
+func configFromServer(h1 *http.Server, h2 *Server) http2Config {
+	conf := http2Config{
+		MaxConcurrentStreams:         h2.MaxConcurrentStreams,
+		MaxEncoderHeaderTableSize:    h2.MaxEncoderHeaderTableSize,
+		MaxDecoderHeaderTableSize:    h2.MaxDecoderHeaderTableSize,
+		MaxReadFrameSize:             h2.MaxReadFrameSize,
+		MaxUploadBufferPerConnection: h2.MaxUploadBufferPerConnection,
+		MaxUploadBufferPerStream:     h2.MaxUploadBufferPerStream,
+		SendPingTimeout:              h2.ReadIdleTimeout,
+		PingTimeout:                  h2.PingTimeout,
+		WriteByteTimeout:             h2.WriteByteTimeout,
+		PermitProhibitedCipherSuites: h2.PermitProhibitedCipherSuites,
+		CountError:                   h2.CountError,
+	}
+	fillNetHTTPServerConfig(&conf, h1)
+	setConfigDefaults(&conf, true)
+	return conf
+}
+
+// configFromServer merges configuration settings from h2 and h2.t1.HTTP2
+// (the net/http Transport).
+func configFromTransport(h2 *Transport) http2Config {
+	conf := http2Config{
+		MaxEncoderHeaderTableSize: h2.MaxEncoderHeaderTableSize,
+		MaxDecoderHeaderTableSize: h2.MaxDecoderHeaderTableSize,
+		MaxReadFrameSize:          h2.MaxReadFrameSize,
+		SendPingTimeout:           h2.ReadIdleTimeout,
+		PingTimeout:               h2.PingTimeout,
+		WriteByteTimeout:          h2.WriteByteTimeout,
+	}
+
+	// Unlike most config fields, where out-of-range values revert to the default,
+	// Transport.MaxReadFrameSize clips.
+	if conf.MaxReadFrameSize < minMaxFrameSize {
+		conf.MaxReadFrameSize = minMaxFrameSize
+	} else if conf.MaxReadFrameSize > maxFrameSize {
+		conf.MaxReadFrameSize = maxFrameSize
+	}
+
+	if h2.t1 != nil {
+		fillNetHTTPTransportConfig(&conf, h2.t1)
+	}
+	setConfigDefaults(&conf, false)
+	return conf
+}
+
+func setDefault[T ~int | ~int32 | ~uint32 | ~int64](v *T, minval, maxval, defval T) {
+	if *v < minval || *v > maxval {
+		*v = defval
+	}
+}
+
+func setConfigDefaults(conf *http2Config, server bool) {
+	setDefault(&conf.MaxConcurrentStreams, 1, math.MaxUint32, defaultMaxStreams)
+	setDefault(&conf.MaxEncoderHeaderTableSize, 1, math.MaxUint32, initialHeaderTableSize)
+	setDefault(&conf.MaxDecoderHeaderTableSize, 1, math.MaxUint32, initialHeaderTableSize)
+	if server {
+		setDefault(&conf.MaxUploadBufferPerConnection, initialWindowSize, math.MaxInt32, 1<<20)
+	} else {
+		setDefault(&conf.MaxUploadBufferPerConnection, initialWindowSize, math.MaxInt32, transportDefaultConnFlow)
+	}
+	if server {
+		setDefault(&conf.MaxUploadBufferPerStream, 1, math.MaxInt32, 1<<20)
+	} else {
+		setDefault(&conf.MaxUploadBufferPerStream, 1, math.MaxInt32, transportDefaultStreamFlow)
+	}
+	setDefault(&conf.MaxReadFrameSize, minMaxFrameSize, maxFrameSize, defaultMaxReadFrameSize)
+	setDefault(&conf.PingTimeout, 1, math.MaxInt64, 15*time.Second)
+}
+
+// adjustHTTP1MaxHeaderSize converts a limit in bytes on the size of an HTTP/1 header
+// to an HTTP/2 MAX_HEADER_LIST_SIZE value.
+func adjustHTTP1MaxHeaderSize(n int64) int64 {
+	// http2's count is in a slightly different unit and includes 32 bytes per pair.
+	// So, take the net/http.Server value and pad it up a bit, assuming 10 headers.
+	const perFieldOverhead = 32 // per http2 spec
+	const typicalHeaders = 10   // conservative
+	return n + typicalHeaders*perFieldOverhead
+}
diff --git a/http2/config_go124.go b/http2/config_go124.go
new file mode 100644
index 000000000..e3784123c
--- /dev/null
+++ b/http2/config_go124.go
@@ -0,0 +1,61 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.24
+
+package http2
+
+import "net/http"
+
+// fillNetHTTPServerConfig sets fields in conf from srv.HTTP2.
+func fillNetHTTPServerConfig(conf *http2Config, srv *http.Server) {
+	fillNetHTTPConfig(conf, srv.HTTP2)
+}
+
+// fillNetHTTPServerConfig sets fields in conf from tr.HTTP2.
+func fillNetHTTPTransportConfig(conf *http2Config, tr *http.Transport) {
+	fillNetHTTPConfig(conf, tr.HTTP2)
+}
+
+func fillNetHTTPConfig(conf *http2Config, h2 *http.HTTP2Config) {
+	if h2 == nil {
+		return
+	}
+	if h2.MaxConcurrentStreams != 0 {
+		conf.MaxConcurrentStreams = uint32(h2.MaxConcurrentStreams)
+	}
+	if h2.MaxEncoderHeaderTableSize != 0 {
+		conf.MaxEncoderHeaderTableSize = uint32(h2.MaxEncoderHeaderTableSize)
+	}
+	if h2.MaxDecoderHeaderTableSize != 0 {
+		conf.MaxDecoderHeaderTableSize = uint32(h2.MaxDecoderHeaderTableSize)
+	}
+	if h2.MaxConcurrentStreams != 0 {
+		conf.MaxConcurrentStreams = uint32(h2.MaxConcurrentStreams)
+	}
+	if h2.MaxReadFrameSize != 0 {
+		conf.MaxReadFrameSize = uint32(h2.MaxReadFrameSize)
+	}
+	if h2.MaxReceiveBufferPerConnection != 0 {
+		conf.MaxUploadBufferPerConnection = int32(h2.MaxReceiveBufferPerConnection)
+	}
+	if h2.MaxReceiveBufferPerStream != 0 {
+		conf.MaxUploadBufferPerStream = int32(h2.MaxReceiveBufferPerStream)
+	}
+	if h2.SendPingTimeout != 0 {
+		conf.SendPingTimeout = h2.SendPingTimeout
+	}
+	if h2.PingTimeout != 0 {
+		conf.PingTimeout = h2.PingTimeout
+	}
+	if h2.WriteByteTimeout != 0 {
+		conf.WriteByteTimeout = h2.WriteByteTimeout
+	}
+	if h2.PermitProhibitedCipherSuites {
+		conf.PermitProhibitedCipherSuites = true
+	}
+	if h2.CountError != nil {
+		conf.CountError = h2.CountError
+	}
+}
diff --git a/http2/config_pre_go124.go b/http2/config_pre_go124.go
new file mode 100644
index 000000000..060fd6c64
--- /dev/null
+++ b/http2/config_pre_go124.go
@@ -0,0 +1,16 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.24
+
+package http2
+
+import "net/http"
+
+// Pre-Go 1.24 fallback.
+// The Server.HTTP2 and Transport.HTTP2 config fields were added in Go 1.24.
+
+func fillNetHTTPServerConfig(conf *http2Config, srv *http.Server) {}
+
+func fillNetHTTPTransportConfig(conf *http2Config, tr *http.Transport) {}
diff --git a/http2/config_test.go b/http2/config_test.go
new file mode 100644
index 000000000..b8e7a7b04
--- /dev/null
+++ b/http2/config_test.go
@@ -0,0 +1,95 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.24
+
+package http2
+
+import (
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestConfigServerSettings(t *testing.T) {
+	config := &http.HTTP2Config{
+		MaxConcurrentStreams:          1,
+		MaxDecoderHeaderTableSize:     1<<20 + 2,
+		MaxEncoderHeaderTableSize:     1<<20 + 3,
+		MaxReadFrameSize:              1<<20 + 4,
+		MaxReceiveBufferPerConnection: 64<<10 + 5,
+		MaxReceiveBufferPerStream:     64<<10 + 6,
+	}
+	const maxHeaderBytes = 4096 + 7
+	st := newServerTester(t, nil, func(s *http.Server) {
+		s.MaxHeaderBytes = maxHeaderBytes
+		s.HTTP2 = config
+	})
+	st.writePreface()
+	st.writeSettings()
+	st.wantSettings(map[SettingID]uint32{
+		SettingMaxConcurrentStreams: uint32(config.MaxConcurrentStreams),
+		SettingHeaderTableSize:      uint32(config.MaxDecoderHeaderTableSize),
+		SettingInitialWindowSize:    uint32(config.MaxReceiveBufferPerStream),
+		SettingMaxFrameSize:         uint32(config.MaxReadFrameSize),
+		SettingMaxHeaderListSize:    maxHeaderBytes + (32 * 10),
+	})
+}
+
+func TestConfigTransportSettings(t *testing.T) {
+	config := &http.HTTP2Config{
+		MaxConcurrentStreams:          1, // ignored by Transport
+		MaxDecoderHeaderTableSize:     1<<20 + 2,
+		MaxEncoderHeaderTableSize:     1<<20 + 3,
+		MaxReadFrameSize:              1<<20 + 4,
+		MaxReceiveBufferPerConnection: 64<<10 + 5,
+		MaxReceiveBufferPerStream:     64<<10 + 6,
+	}
+	const maxHeaderBytes = 4096 + 7
+	tc := newTestClientConn(t, func(tr *http.Transport) {
+		tr.HTTP2 = config
+		tr.MaxResponseHeaderBytes = maxHeaderBytes
+	})
+	tc.wantSettings(map[SettingID]uint32{
+		SettingHeaderTableSize:   uint32(config.MaxDecoderHeaderTableSize),
+		SettingInitialWindowSize: uint32(config.MaxReceiveBufferPerStream),
+		SettingMaxFrameSize:      uint32(config.MaxReadFrameSize),
+		SettingMaxHeaderListSize: maxHeaderBytes + (32 * 10),
+	})
+	tc.wantWindowUpdate(0, uint32(config.MaxReceiveBufferPerConnection))
+}
+
+func TestConfigPingTimeoutServer(t *testing.T) {
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+	}, func(s *Server) {
+		s.ReadIdleTimeout = 2 * time.Second
+		s.PingTimeout = 3 * time.Second
+	})
+	st.greet()
+
+	st.advance(2 * time.Second)
+	_ = readFrame[*PingFrame](t, st)
+	st.advance(3 * time.Second)
+	st.wantClosed()
+}
+
+func TestConfigPingTimeoutTransport(t *testing.T) {
+	tc := newTestClientConn(t, func(tr *Transport) {
+		tr.ReadIdleTimeout = 2 * time.Second
+		tr.PingTimeout = 3 * time.Second
+	})
+	tc.greet()
+
+	req, _ := http.NewRequest("GET", "https://dummy.tld/", nil)
+	rt := tc.roundTrip(req)
+	tc.wantFrameType(FrameHeaders)
+
+	tc.advance(2 * time.Second)
+	tc.wantFrameType(FramePing)
+	tc.advance(3 * time.Second)
+	err := rt.err()
+	if err == nil {
+		t.Fatalf("expected connection to close")
+	}
+}
diff --git a/http2/connframes_test.go b/http2/connframes_test.go
index 7db8b74e2..2c4532571 100644
--- a/http2/connframes_test.go
+++ b/http2/connframes_test.go
@@ -6,7 +6,6 @@ package http2
 
 import (
 	"bytes"
-	"context"
 	"io"
 	"net/http"
 	"os"
@@ -262,6 +261,24 @@ func (tf *testConnFramer) wantRSTStream(streamID uint32, code ErrCode) {
 	}
 }
 
+func (tf *testConnFramer) wantSettings(want map[SettingID]uint32) {
+	fr := readFrame[*SettingsFrame](tf.t, tf)
+	if fr.Header().Flags.Has(FlagSettingsAck) {
+		tf.t.Errorf("got SETTINGS frame with ACK set, want no ACK")
+	}
+	for wantID, wantVal := range want {
+		gotVal, ok := fr.Value(wantID)
+		if !ok {
+			tf.t.Errorf("SETTINGS: %v is not set, want %v", wantID, wantVal)
+		} else if gotVal != wantVal {
+			tf.t.Errorf("SETTINGS: %v is %v, want %v", wantID, gotVal, wantVal)
+		}
+	}
+	if tf.t.Failed() {
+		tf.t.Fatalf("%v", fr)
+	}
+}
+
 func (tf *testConnFramer) wantSettingsAck() {
 	tf.t.Helper()
 	fr := readFrame[*SettingsFrame](tf.t, tf)
@@ -295,7 +312,7 @@ func (tf *testConnFramer) wantClosed() {
 	if err == nil {
 		tf.t.Fatalf("got unexpected frame (want closed connection): %v", fr)
 	}
-	if err == context.DeadlineExceeded {
+	if err == os.ErrDeadlineExceeded {
 		tf.t.Fatalf("connection is not closed; want it to be")
 	}
 }
@@ -306,7 +323,7 @@ func (tf *testConnFramer) wantIdle() {
 	if err == nil {
 		tf.t.Fatalf("got unexpected frame (want idle connection): %v", fr)
 	}
-	if err != context.DeadlineExceeded {
+	if err != os.ErrDeadlineExceeded {
 		tf.t.Fatalf("got unexpected frame error (want idle connection): %v", err)
 	}
 }
diff --git a/http2/http2.go b/http2/http2.go
index 003e649f3..7688c356b 100644
--- a/http2/http2.go
+++ b/http2/http2.go
@@ -19,8 +19,9 @@ import (
 	"bufio"
 	"context"
 	"crypto/tls"
+	"errors"
 	"fmt"
-	"io"
+	"net"
 	"net/http"
 	"os"
 	"sort"
@@ -237,13 +238,19 @@ func (cw closeWaiter) Wait() {
 // Its buffered writer is lazily allocated as needed, to minimize
 // idle memory usage with many connections.
 type bufferedWriter struct {
-	_  incomparable
-	w  io.Writer     // immutable
-	bw *bufio.Writer // non-nil when data is buffered
+	_           incomparable
+	group       synctestGroupInterface // immutable
+	conn        net.Conn               // immutable
+	bw          *bufio.Writer          // non-nil when data is buffered
+	byteTimeout time.Duration          // immutable, WriteByteTimeout
 }
 
-func newBufferedWriter(w io.Writer) *bufferedWriter {
-	return &bufferedWriter{w: w}
+func newBufferedWriter(group synctestGroupInterface, conn net.Conn, timeout time.Duration) *bufferedWriter {
+	return &bufferedWriter{
+		group:       group,
+		conn:        conn,
+		byteTimeout: timeout,
+	}
 }
 
 // bufWriterPoolBufferSize is the size of bufio.Writer's
@@ -270,7 +277,7 @@ func (w *bufferedWriter) Available() int {
 func (w *bufferedWriter) Write(p []byte) (n int, err error) {
 	if w.bw == nil {
 		bw := bufWriterPool.Get().(*bufio.Writer)
-		bw.Reset(w.w)
+		bw.Reset((*bufferedWriterTimeoutWriter)(w))
 		w.bw = bw
 	}
 	return w.bw.Write(p)
@@ -288,6 +295,38 @@ func (w *bufferedWriter) Flush() error {
 	return err
 }
 
+type bufferedWriterTimeoutWriter bufferedWriter
+
+func (w *bufferedWriterTimeoutWriter) Write(p []byte) (n int, err error) {
+	return writeWithByteTimeout(w.group, w.conn, w.byteTimeout, p)
+}
+
+// writeWithByteTimeout writes to conn.
+// If more than timeout passes without any bytes being written to the connection,
+// the write fails.
+func writeWithByteTimeout(group synctestGroupInterface, conn net.Conn, timeout time.Duration, p []byte) (n int, err error) {
+	if timeout <= 0 {
+		return conn.Write(p)
+	}
+	for {
+		var now time.Time
+		if group == nil {
+			now = time.Now()
+		} else {
+			now = group.Now()
+		}
+		conn.SetWriteDeadline(now.Add(timeout))
+		nn, err := conn.Write(p[n:])
+		n += nn
+		if n == len(p) || nn == 0 || !errors.Is(err, os.ErrDeadlineExceeded) {
+			// Either we finished the write, made no progress, or hit the deadline.
+			// Whichever it is, we're done now.
+			conn.SetWriteDeadline(time.Time{})
+			return n, err
+		}
+	}
+}
+
 func mustUint31(v int32) uint32 {
 	if v < 0 || v > 2147483647 {
 		panic("out of range")
diff --git a/http2/server.go b/http2/server.go
index 6c349f3ec..617b4a476 100644
--- a/http2/server.go
+++ b/http2/server.go
@@ -29,6 +29,7 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"crypto/rand"
 	"crypto/tls"
 	"errors"
 	"fmt"
@@ -52,10 +53,14 @@ import (
 )
 
 const (
-	prefaceTimeout         = 10 * time.Second
-	firstSettingsTimeout   = 2 * time.Second // should be in-flight with preface anyway
-	handlerChunkWriteSize  = 4 << 10
-	defaultMaxStreams      = 250 // TODO: make this 100 as the GFE seems to?
+	prefaceTimeout        = 10 * time.Second
+	firstSettingsTimeout  = 2 * time.Second // should be in-flight with preface anyway
+	handlerChunkWriteSize = 4 << 10
+	defaultMaxStreams     = 250 // TODO: make this 100 as the GFE seems to?
+
+	// maxQueuedControlFrames is the maximum number of control frames like
+	// SETTINGS, PING and RST_STREAM that will be queued for writing before
+	// the connection is closed to prevent memory exhaustion attacks.
 	maxQueuedControlFrames = 10000
 )
 
@@ -127,6 +132,22 @@ type Server struct {
 	// If zero or negative, there is no timeout.
 	IdleTimeout time.Duration
 
+	// ReadIdleTimeout is the timeout after which a health check using a ping
+	// frame will be carried out if no frame is received on the connection.
+	// If zero, no health check is performed.
+	ReadIdleTimeout time.Duration
+
+	// PingTimeout is the timeout after which the connection will be closed
+	// if a response to a ping is not received.
+	// If zero, a default of 15 seconds is used.
+	PingTimeout time.Duration
+
+	// WriteByteTimeout is the timeout after which a connection will be
+	// closed if no data can be written to it. The timeout begins when data is
+	// available to write, and is extended whenever any bytes are written.
+	// If zero or negative, there is no timeout.
+	WriteByteTimeout time.Duration
+
 	// MaxUploadBufferPerConnection is the size of the initial flow
 	// control window for each connections. The HTTP/2 spec does not
 	// allow this to be smaller than 65535 or larger than 2^32-1.
@@ -189,57 +210,6 @@ func (s *Server) afterFunc(d time.Duration, f func()) timer {
 	return timeTimer{time.AfterFunc(d, f)}
 }
 
-func (s *Server) initialConnRecvWindowSize() int32 {
-	if s.MaxUploadBufferPerConnection >= initialWindowSize {
-		return s.MaxUploadBufferPerConnection
-	}
-	return 1 << 20
-}
-
-func (s *Server) initialStreamRecvWindowSize() int32 {
-	if s.MaxUploadBufferPerStream > 0 {
-		return s.MaxUploadBufferPerStream
-	}
-	return 1 << 20
-}
-
-func (s *Server) maxReadFrameSize() uint32 {
-	if v := s.MaxReadFrameSize; v >= minMaxFrameSize && v <= maxFrameSize {
-		return v
-	}
-	return defaultMaxReadFrameSize
-}
-
-func (s *Server) maxConcurrentStreams() uint32 {
-	if v := s.MaxConcurrentStreams; v > 0 {
-		return v
-	}
-	return defaultMaxStreams
-}
-
-func (s *Server) maxDecoderHeaderTableSize() uint32 {
-	if v := s.MaxDecoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
-func (s *Server) maxEncoderHeaderTableSize() uint32 {
-	if v := s.MaxEncoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
-// maxQueuedControlFrames is the maximum number of control frames like
-// SETTINGS, PING and RST_STREAM that will be queued for writing before
-// the connection is closed to prevent memory exhaustion attacks.
-func (s *Server) maxQueuedControlFrames() int {
-	// TODO: if anybody asks, add a Server field, and remember to define the
-	// behavior of negative values.
-	return maxQueuedControlFrames
-}
-
 type serverInternalState struct {
 	mu          sync.Mutex
 	activeConns map[*serverConn]struct{}
@@ -440,13 +410,15 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 	baseCtx, cancel := serverConnBaseContext(c, opts)
 	defer cancel()
 
+	http1srv := opts.baseConfig()
+	conf := configFromServer(http1srv, s)
 	sc := &serverConn{
 		srv:                         s,
-		hs:                          opts.baseConfig(),
+		hs:                          http1srv,
 		conn:                        c,
 		baseCtx:                     baseCtx,
 		remoteAddrStr:               c.RemoteAddr().String(),
-		bw:                          newBufferedWriter(c),
+		bw:                          newBufferedWriter(s.group, c, conf.WriteByteTimeout),
 		handler:                     opts.handler(),
 		streams:                     make(map[uint32]*stream),
 		readFrameCh:                 make(chan readFrameResult),
@@ -456,9 +428,12 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 		bodyReadCh:                  make(chan bodyReadMsg),         // buffering doesn't matter either way
 		doneServing:                 make(chan struct{}),
 		clientMaxStreams:            math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value"
-		advMaxStreams:               s.maxConcurrentStreams(),
+		advMaxStreams:               conf.MaxConcurrentStreams,
 		initialStreamSendWindowSize: initialWindowSize,
+		initialStreamRecvWindowSize: conf.MaxUploadBufferPerStream,
 		maxFrameSize:                initialMaxFrameSize,
+		pingTimeout:                 conf.PingTimeout,
+		countErrorFunc:              conf.CountError,
 		serveG:                      newGoroutineLock(),
 		pushEnabled:                 true,
 		sawClientPreface:            opts.SawClientPreface,
@@ -491,15 +466,15 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 	sc.flow.add(initialWindowSize)
 	sc.inflow.init(initialWindowSize)
 	sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
-	sc.hpackEncoder.SetMaxDynamicTableSizeLimit(s.maxEncoderHeaderTableSize())
+	sc.hpackEncoder.SetMaxDynamicTableSizeLimit(conf.MaxEncoderHeaderTableSize)
 
 	fr := NewFramer(sc.bw, c)
-	if s.CountError != nil {
-		fr.countError = s.CountError
+	if conf.CountError != nil {
+		fr.countError = conf.CountError
 	}
-	fr.ReadMetaHeaders = hpack.NewDecoder(s.maxDecoderHeaderTableSize(), nil)
+	fr.ReadMetaHeaders = hpack.NewDecoder(conf.MaxDecoderHeaderTableSize, nil)
 	fr.MaxHeaderListSize = sc.maxHeaderListSize()
-	fr.SetMaxReadFrameSize(s.maxReadFrameSize())
+	fr.SetMaxReadFrameSize(conf.MaxReadFrameSize)
 	sc.framer = fr
 
 	if tc, ok := c.(connectionStater); ok {
@@ -532,7 +507,7 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 			// So for now, do nothing here again.
 		}
 
-		if !s.PermitProhibitedCipherSuites && isBadCipher(sc.tlsState.CipherSuite) {
+		if !conf.PermitProhibitedCipherSuites && isBadCipher(sc.tlsState.CipherSuite) {
 			// "Endpoints MAY choose to generate a connection error
 			// (Section 5.4.1) of type INADEQUATE_SECURITY if one of
 			// the prohibited cipher suites are negotiated."
@@ -569,7 +544,7 @@ func (s *Server) serveConn(c net.Conn, opts *ServeConnOpts, newf func(*serverCon
 		opts.UpgradeRequest = nil
 	}
 
-	sc.serve()
+	sc.serve(conf)
 }
 
 func serverConnBaseContext(c net.Conn, opts *ServeConnOpts) (ctx context.Context, cancel func()) {
@@ -609,6 +584,7 @@ type serverConn struct {
 	tlsState         *tls.ConnectionState   // shared by all handlers, like net/http
 	remoteAddrStr    string
 	writeSched       WriteScheduler
+	countErrorFunc   func(errType string)
 
 	// Everything following is owned by the serve loop; use serveG.check():
 	serveG                      goroutineLock // used to verify funcs are on serve()
@@ -628,6 +604,7 @@ type serverConn struct {
 	streams                     map[uint32]*stream
 	unstartedHandlers           []unstartedHandler
 	initialStreamSendWindowSize int32
+	initialStreamRecvWindowSize int32
 	maxFrameSize                int32
 	peerMaxHeaderListSize       uint32            // zero means unknown (default)
 	canonHeader                 map[string]string // http2-lower-case -> Go-Canonical-Case
@@ -638,9 +615,14 @@ type serverConn struct {
 	inGoAway                    bool              // we've started to or sent GOAWAY
 	inFrameScheduleLoop         bool              // whether we're in the scheduleFrameWrite loop
 	needToSendGoAway            bool              // we need to schedule a GOAWAY frame write
+	pingSent                    bool
+	sentPingData                [8]byte
 	goAwayCode                  ErrCode
 	shutdownTimer               timer // nil until used
 	idleTimer                   timer // nil if unused
+	readIdleTimeout             time.Duration
+	pingTimeout                 time.Duration
+	readIdleTimer               timer // nil if unused
 
 	// Owned by the writeFrameAsync goroutine:
 	headerWriteBuf bytes.Buffer
@@ -655,11 +637,7 @@ func (sc *serverConn) maxHeaderListSize() uint32 {
 	if n <= 0 {
 		n = http.DefaultMaxHeaderBytes
 	}
-	// http2's count is in a slightly different unit and includes 32 bytes per pair.
-	// So, take the net/http.Server value and pad it up a bit, assuming 10 headers.
-	const perFieldOverhead = 32 // per http2 spec
-	const typicalHeaders = 10   // conservative
-	return uint32(n + typicalHeaders*perFieldOverhead)
+	return uint32(adjustHTTP1MaxHeaderSize(int64(n)))
 }
 
 func (sc *serverConn) curOpenStreams() uint32 {
@@ -923,7 +901,7 @@ func (sc *serverConn) notePanic() {
 	}
 }
 
-func (sc *serverConn) serve() {
+func (sc *serverConn) serve(conf http2Config) {
 	sc.serveG.check()
 	defer sc.notePanic()
 	defer sc.conn.Close()
@@ -937,18 +915,18 @@ func (sc *serverConn) serve() {
 
 	sc.writeFrame(FrameWriteRequest{
 		write: writeSettings{
-			{SettingMaxFrameSize, sc.srv.maxReadFrameSize()},
+			{SettingMaxFrameSize, conf.MaxReadFrameSize},
 			{SettingMaxConcurrentStreams, sc.advMaxStreams},
 			{SettingMaxHeaderListSize, sc.maxHeaderListSize()},
-			{SettingHeaderTableSize, sc.srv.maxDecoderHeaderTableSize()},
-			{SettingInitialWindowSize, uint32(sc.srv.initialStreamRecvWindowSize())},
+			{SettingHeaderTableSize, conf.MaxDecoderHeaderTableSize},
+			{SettingInitialWindowSize, uint32(sc.initialStreamRecvWindowSize)},
 		},
 	})
 	sc.unackedSettings++
 
 	// Each connection starts with initialWindowSize inflow tokens.
 	// If a higher value is configured, we add more tokens.
-	if diff := sc.srv.initialConnRecvWindowSize() - initialWindowSize; diff > 0 {
+	if diff := conf.MaxUploadBufferPerConnection - initialWindowSize; diff > 0 {
 		sc.sendWindowUpdate(nil, int(diff))
 	}
 
@@ -968,11 +946,18 @@ func (sc *serverConn) serve() {
 		defer sc.idleTimer.Stop()
 	}
 
+	if conf.SendPingTimeout > 0 {
+		sc.readIdleTimeout = conf.SendPingTimeout
+		sc.readIdleTimer = sc.srv.afterFunc(conf.SendPingTimeout, sc.onReadIdleTimer)
+		defer sc.readIdleTimer.Stop()
+	}
+
 	go sc.readFrames() // closed by defer sc.conn.Close above
 
 	settingsTimer := sc.srv.afterFunc(firstSettingsTimeout, sc.onSettingsTimer)
 	defer settingsTimer.Stop()
 
+	lastFrameTime := sc.srv.now()
 	loopNum := 0
 	for {
 		loopNum++
@@ -986,6 +971,7 @@ func (sc *serverConn) serve() {
 		case res := <-sc.wroteFrameCh:
 			sc.wroteFrame(res)
 		case res := <-sc.readFrameCh:
+			lastFrameTime = sc.srv.now()
 			// Process any written frames before reading new frames from the client since a
 			// written frame could have triggered a new stream to be started.
 			if sc.writingFrameAsync {
@@ -1017,6 +1003,8 @@ func (sc *serverConn) serve() {
 				case idleTimerMsg:
 					sc.vlogf("connection is idle")
 					sc.goAway(ErrCodeNo)
+				case readIdleTimerMsg:
+					sc.handlePingTimer(lastFrameTime)
 				case shutdownTimerMsg:
 					sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
 					return
@@ -1039,7 +1027,7 @@ func (sc *serverConn) serve() {
 		// If the peer is causing us to generate a lot of control frames,
 		// but not reading them from us, assume they are trying to make us
 		// run out of memory.
-		if sc.queuedControlFrames > sc.srv.maxQueuedControlFrames() {
+		if sc.queuedControlFrames > maxQueuedControlFrames {
 			sc.vlogf("http2: too many control frames in send queue, closing connection")
 			return
 		}
@@ -1055,12 +1043,39 @@ func (sc *serverConn) serve() {
 	}
 }
 
+func (sc *serverConn) handlePingTimer(lastFrameReadTime time.Time) {
+	if sc.pingSent {
+		sc.vlogf("timeout waiting for PING response")
+		sc.conn.Close()
+		return
+	}
+
+	pingAt := lastFrameReadTime.Add(sc.readIdleTimeout)
+	now := sc.srv.now()
+	if pingAt.After(now) {
+		// We received frames since arming the ping timer.
+		// Reset it for the next possible timeout.
+		sc.readIdleTimer.Reset(pingAt.Sub(now))
+		return
+	}
+
+	sc.pingSent = true
+	// Ignore crypto/rand.Read errors: It generally can't fail, and worse case if it does
+	// is we send a PING frame containing 0s.
+	_, _ = rand.Read(sc.sentPingData[:])
+	sc.writeFrame(FrameWriteRequest{
+		write: &writePing{data: sc.sentPingData},
+	})
+	sc.readIdleTimer.Reset(sc.pingTimeout)
+}
+
 type serverMessage int
 
 // Message values sent to serveMsgCh.
 var (
 	settingsTimerMsg    = new(serverMessage)
 	idleTimerMsg        = new(serverMessage)
+	readIdleTimerMsg    = new(serverMessage)
 	shutdownTimerMsg    = new(serverMessage)
 	gracefulShutdownMsg = new(serverMessage)
 	handlerDoneMsg      = new(serverMessage)
@@ -1068,6 +1083,7 @@ var (
 
 func (sc *serverConn) onSettingsTimer() { sc.sendServeMsg(settingsTimerMsg) }
 func (sc *serverConn) onIdleTimer()     { sc.sendServeMsg(idleTimerMsg) }
+func (sc *serverConn) onReadIdleTimer() { sc.sendServeMsg(readIdleTimerMsg) }
 func (sc *serverConn) onShutdownTimer() { sc.sendServeMsg(shutdownTimerMsg) }
 
 func (sc *serverConn) sendServeMsg(msg interface{}) {
@@ -1320,6 +1336,10 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 	sc.writingFrame = false
 	sc.writingFrameAsync = false
 
+	if res.err != nil {
+		sc.conn.Close()
+	}
+
 	wr := res.wr
 
 	if writeEndsStream(wr.write) {
@@ -1594,6 +1614,11 @@ func (sc *serverConn) processFrame(f Frame) error {
 func (sc *serverConn) processPing(f *PingFrame) error {
 	sc.serveG.check()
 	if f.IsAck() {
+		if sc.pingSent && sc.sentPingData == f.Data {
+			// This is a response to a PING we sent.
+			sc.pingSent = false
+			sc.readIdleTimer.Reset(sc.readIdleTimeout)
+		}
 		// 6.7 PING: " An endpoint MUST NOT respond to PING frames
 		// containing this flag."
 		return nil
@@ -2160,7 +2185,7 @@ func (sc *serverConn) newStream(id, pusherID uint32, state streamState) *stream
 	st.cw.Init()
 	st.flow.conn = &sc.flow // link to conn-level counter
 	st.flow.add(sc.initialStreamSendWindowSize)
-	st.inflow.init(sc.srv.initialStreamRecvWindowSize())
+	st.inflow.init(sc.initialStreamRecvWindowSize)
 	if sc.hs.WriteTimeout > 0 {
 		st.writeDeadline = sc.srv.afterFunc(sc.hs.WriteTimeout, st.onWriteTimeout)
 	}
@@ -3301,7 +3326,7 @@ func (sc *serverConn) countError(name string, err error) error {
 	if sc == nil || sc.srv == nil {
 		return err
 	}
-	f := sc.srv.CountError
+	f := sc.countErrorFunc
 	if f == nil {
 		return err
 	}
diff --git a/http2/server_test.go b/http2/server_test.go
index 47c3c619c..77de1be20 100644
--- a/http2/server_test.go
+++ b/http2/server_test.go
@@ -461,7 +461,8 @@ func (st *serverTester) greetAndCheckSettings(checkSetting func(s Setting) error
 			if f.FrameHeader.StreamID != 0 {
 				st.t.Fatalf("WindowUpdate StreamID = %d; want 0", f.FrameHeader.StreamID)
 			}
-			incr := uint32(st.sc.srv.initialConnRecvWindowSize() - initialWindowSize)
+			conf := configFromServer(st.sc.hs, st.sc.srv)
+			incr := uint32(conf.MaxUploadBufferPerConnection - initialWindowSize)
 			if f.Increment != incr {
 				st.t.Fatalf("WindowUpdate increment = %d; want %d", f.Increment, incr)
 			}
@@ -589,11 +590,12 @@ func (st *serverTester) bodylessReq1(headers ...string) {
 }
 
 func (st *serverTester) wantFlowControlConsumed(streamID, consumed int32) {
+	conf := configFromServer(st.sc.hs, st.sc.srv)
 	var initial int32
 	if streamID == 0 {
-		initial = st.sc.srv.initialConnRecvWindowSize()
+		initial = conf.MaxUploadBufferPerConnection
 	} else {
-		initial = st.sc.srv.initialStreamRecvWindowSize()
+		initial = conf.MaxUploadBufferPerStream
 	}
 	donec := make(chan struct{})
 	st.sc.sendServeMsg(func(sc *serverConn) {
@@ -4674,3 +4676,78 @@ func TestServerSetReadWriteDeadlineRace(t *testing.T) {
 	}
 	resp.Body.Close()
 }
+
+func TestServerWriteByteTimeout(t *testing.T) {
+	const timeout = 1 * time.Second
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+		w.Write(make([]byte, 100))
+	}, func(s *Server) {
+		s.WriteByteTimeout = timeout
+	})
+	st.greet()
+
+	st.cc.(*synctestNetConn).SetReadBufferSize(1) // write one byte at a time
+	st.writeHeaders(HeadersFrameParam{
+		StreamID:      1,
+		BlockFragment: st.encodeHeader(),
+		EndStream:     true,
+		EndHeaders:    true,
+	})
+
+	// Read a few bytes, staying just under WriteByteTimeout.
+	for i := 0; i < 10; i++ {
+		st.advance(timeout - 1)
+		if n, err := st.cc.Read(make([]byte, 1)); n != 1 || err != nil {
+			t.Fatalf("read %v: %v, %v; want 1, nil", i, n, err)
+		}
+	}
+
+	// Wait for WriteByteTimeout.
+	// The connection should close.
+	st.advance(1 * time.Second) // timeout after writing one byte
+	st.advance(1 * time.Second) // timeout after failing to write any more bytes
+	st.wantClosed()
+}
+
+func TestServerPingSent(t *testing.T) {
+	const readIdleTimeout = 15 * time.Second
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+	}, func(s *Server) {
+		s.ReadIdleTimeout = readIdleTimeout
+	})
+	st.greet()
+
+	st.wantIdle()
+
+	st.advance(readIdleTimeout)
+	_ = readFrame[*PingFrame](t, st)
+	st.wantIdle()
+
+	st.advance(14 * time.Second)
+	st.wantIdle()
+	st.advance(1 * time.Second)
+	st.wantClosed()
+}
+
+func TestServerPingResponded(t *testing.T) {
+	const readIdleTimeout = 15 * time.Second
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+	}, func(s *Server) {
+		s.ReadIdleTimeout = readIdleTimeout
+	})
+	st.greet()
+
+	st.wantIdle()
+
+	st.advance(readIdleTimeout)
+	pf := readFrame[*PingFrame](t, st)
+	st.wantIdle()
+
+	st.advance(14 * time.Second)
+	st.wantIdle()
+
+	st.writePing(true, pf.Data)
+
+	st.advance(2 * time.Second)
+	st.wantIdle()
+}
diff --git a/http2/transport.go b/http2/transport.go
index 61f511f97..0c5f64aa8 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -25,7 +25,6 @@ import (
 	"net/http"
 	"net/http/httptrace"
 	"net/textproto"
-	"os"
 	"sort"
 	"strconv"
 	"strings"
@@ -227,40 +226,26 @@ func (t *Transport) contextWithTimeout(ctx context.Context, d time.Duration) (co
 }
 
 func (t *Transport) maxHeaderListSize() uint32 {
-	if t.MaxHeaderListSize == 0 {
+	n := int64(t.MaxHeaderListSize)
+	if t.t1 != nil && t.t1.MaxResponseHeaderBytes != 0 {
+		n = t.t1.MaxResponseHeaderBytes
+		if n > 0 {
+			n = adjustHTTP1MaxHeaderSize(n)
+		}
+	}
+	if n <= 0 {
 		return 10 << 20
 	}
-	if t.MaxHeaderListSize == 0xffffffff {
+	if n >= 0xffffffff {
 		return 0
 	}
-	return t.MaxHeaderListSize
-}
-
-func (t *Transport) maxFrameReadSize() uint32 {
-	if t.MaxReadFrameSize == 0 {
-		return 0 // use the default provided by the peer
-	}
-	if t.MaxReadFrameSize < minMaxFrameSize {
-		return minMaxFrameSize
-	}
-	if t.MaxReadFrameSize > maxFrameSize {
-		return maxFrameSize
-	}
-	return t.MaxReadFrameSize
+	return uint32(n)
 }
 
 func (t *Transport) disableCompression() bool {
 	return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
 }
 
-func (t *Transport) pingTimeout() time.Duration {
-	if t.PingTimeout == 0 {
-		return 15 * time.Second
-	}
-	return t.PingTimeout
-
-}
-
 // ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
 // It returns an error if t1 has already been HTTP/2-enabled.
 //
@@ -370,11 +355,14 @@ type ClientConn struct {
 	lastActive      time.Time
 	lastIdle        time.Time // time last idle
 	// Settings from peer: (also guarded by wmu)
-	maxFrameSize           uint32
-	maxConcurrentStreams   uint32
-	peerMaxHeaderListSize  uint64
-	peerMaxHeaderTableSize uint32
-	initialWindowSize      uint32
+	maxFrameSize                uint32
+	maxConcurrentStreams        uint32
+	peerMaxHeaderListSize       uint64
+	peerMaxHeaderTableSize      uint32
+	initialWindowSize           uint32
+	initialStreamRecvWindowSize int32
+	readIdleTimeout             time.Duration
+	pingTimeout                 time.Duration
 
 	// reqHeaderMu is a 1-element semaphore channel controlling access to sending new requests.
 	// Write to reqHeaderMu to lock it, read from it to unlock.
@@ -499,6 +487,7 @@ func (cs *clientStream) closeReqBodyLocked() {
 }
 
 type stickyErrWriter struct {
+	group   synctestGroupInterface
 	conn    net.Conn
 	timeout time.Duration
 	err     *error
@@ -508,22 +497,9 @@ func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	if *sew.err != nil {
 		return 0, *sew.err
 	}
-	for {
-		if sew.timeout != 0 {
-			sew.conn.SetWriteDeadline(time.Now().Add(sew.timeout))
-		}
-		nn, err := sew.conn.Write(p[n:])
-		n += nn
-		if n < len(p) && nn > 0 && errors.Is(err, os.ErrDeadlineExceeded) {
-			// Keep extending the deadline so long as we're making progress.
-			continue
-		}
-		if sew.timeout != 0 {
-			sew.conn.SetWriteDeadline(time.Time{})
-		}
-		*sew.err = err
-		return n, err
-	}
+	n, err = writeWithByteTimeout(sew.group, sew.conn, sew.timeout, p)
+	*sew.err = err
+	return n, err
 }
 
 // noCachedConnError is the concrete type of ErrNoCachedConn, which
@@ -758,44 +734,36 @@ func (t *Transport) expectContinueTimeout() time.Duration {
 	return t.t1.ExpectContinueTimeout
 }
 
-func (t *Transport) maxDecoderHeaderTableSize() uint32 {
-	if v := t.MaxDecoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
-func (t *Transport) maxEncoderHeaderTableSize() uint32 {
-	if v := t.MaxEncoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
 func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
 	return t.newClientConn(c, t.disableKeepAlives())
 }
 
 func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, error) {
+	conf := configFromTransport(t)
 	cc := &ClientConn{
-		t:                     t,
-		tconn:                 c,
-		readerDone:            make(chan struct{}),
-		nextStreamID:          1,
-		maxFrameSize:          16 << 10,                    // spec default
-		initialWindowSize:     65535,                       // spec default
-		maxConcurrentStreams:  initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.
-		peerMaxHeaderListSize: 0xffffffffffffffff,          // "infinite", per spec. Use 2^64-1 instead.
-		streams:               make(map[uint32]*clientStream),
-		singleUse:             singleUse,
-		wantSettingsAck:       true,
-		pings:                 make(map[[8]byte]chan struct{}),
-		reqHeaderMu:           make(chan struct{}, 1),
-	}
+		t:                           t,
+		tconn:                       c,
+		readerDone:                  make(chan struct{}),
+		nextStreamID:                1,
+		maxFrameSize:                16 << 10, // spec default
+		initialWindowSize:           65535,    // spec default
+		initialStreamRecvWindowSize: conf.MaxUploadBufferPerStream,
+		maxConcurrentStreams:        initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.
+		peerMaxHeaderListSize:       0xffffffffffffffff,          // "infinite", per spec. Use 2^64-1 instead.
+		streams:                     make(map[uint32]*clientStream),
+		singleUse:                   singleUse,
+		wantSettingsAck:             true,
+		readIdleTimeout:             conf.SendPingTimeout,
+		pingTimeout:                 conf.PingTimeout,
+		pings:                       make(map[[8]byte]chan struct{}),
+		reqHeaderMu:                 make(chan struct{}, 1),
+	}
+	var group synctestGroupInterface
 	if t.transportTestHooks != nil {
 		t.markNewGoroutine()
 		t.transportTestHooks.newclientconn(cc)
 		c = cc.tconn
+		group = t.group
 	}
 	if VerboseLogs {
 		t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr())
@@ -807,24 +775,23 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 	// TODO: adjust this writer size to account for frame size +
 	// MTU + crypto/tls record padding.
 	cc.bw = bufio.NewWriter(stickyErrWriter{
+		group:   group,
 		conn:    c,
-		timeout: t.WriteByteTimeout,
+		timeout: conf.WriteByteTimeout,
 		err:     &cc.werr,
 	})
 	cc.br = bufio.NewReader(c)
 	cc.fr = NewFramer(cc.bw, cc.br)
-	if t.maxFrameReadSize() != 0 {
-		cc.fr.SetMaxReadFrameSize(t.maxFrameReadSize())
-	}
+	cc.fr.SetMaxReadFrameSize(conf.MaxReadFrameSize)
 	if t.CountError != nil {
 		cc.fr.countError = t.CountError
 	}
-	maxHeaderTableSize := t.maxDecoderHeaderTableSize()
+	maxHeaderTableSize := conf.MaxDecoderHeaderTableSize
 	cc.fr.ReadMetaHeaders = hpack.NewDecoder(maxHeaderTableSize, nil)
 	cc.fr.MaxHeaderListSize = t.maxHeaderListSize()
 
 	cc.henc = hpack.NewEncoder(&cc.hbuf)
-	cc.henc.SetMaxDynamicTableSizeLimit(t.maxEncoderHeaderTableSize())
+	cc.henc.SetMaxDynamicTableSizeLimit(conf.MaxEncoderHeaderTableSize)
 	cc.peerMaxHeaderTableSize = initialHeaderTableSize
 
 	if cs, ok := c.(connectionStater); ok {
@@ -834,11 +801,9 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 
 	initialSettings := []Setting{
 		{ID: SettingEnablePush, Val: 0},
-		{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
-	}
-	if max := t.maxFrameReadSize(); max != 0 {
-		initialSettings = append(initialSettings, Setting{ID: SettingMaxFrameSize, Val: max})
+		{ID: SettingInitialWindowSize, Val: uint32(cc.initialStreamRecvWindowSize)},
 	}
+	initialSettings = append(initialSettings, Setting{ID: SettingMaxFrameSize, Val: conf.MaxReadFrameSize})
 	if max := t.maxHeaderListSize(); max != 0 {
 		initialSettings = append(initialSettings, Setting{ID: SettingMaxHeaderListSize, Val: max})
 	}
@@ -848,8 +813,8 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 
 	cc.bw.Write(clientPreface)
 	cc.fr.WriteSettings(initialSettings...)
-	cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow)
-	cc.inflow.init(transportDefaultConnFlow + initialWindowSize)
+	cc.fr.WriteWindowUpdate(0, uint32(conf.MaxUploadBufferPerConnection))
+	cc.inflow.init(conf.MaxUploadBufferPerConnection + initialWindowSize)
 	cc.bw.Flush()
 	if cc.werr != nil {
 		cc.Close()
@@ -867,7 +832,7 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 }
 
 func (cc *ClientConn) healthCheck() {
-	pingTimeout := cc.t.pingTimeout()
+	pingTimeout := cc.pingTimeout
 	// We don't need to periodically ping in the health check, because the readLoop of ClientConn will
 	// trigger the healthCheck again if there is no frame received.
 	ctx, cancel := cc.t.contextWithTimeout(context.Background(), pingTimeout)
@@ -2199,7 +2164,7 @@ type resAndError struct {
 func (cc *ClientConn) addStreamLocked(cs *clientStream) {
 	cs.flow.add(int32(cc.initialWindowSize))
 	cs.flow.setConnFlow(&cc.flow)
-	cs.inflow.init(transportDefaultStreamFlow)
+	cs.inflow.init(cc.initialStreamRecvWindowSize)
 	cs.ID = cc.nextStreamID
 	cc.nextStreamID += 2
 	cc.streams[cs.ID] = cs
@@ -2345,7 +2310,7 @@ func (cc *ClientConn) countReadFrameError(err error) {
 func (rl *clientConnReadLoop) run() error {
 	cc := rl.cc
 	gotSettings := false
-	readIdleTimeout := cc.t.ReadIdleTimeout
+	readIdleTimeout := cc.readIdleTimeout
 	var t timer
 	if readIdleTimeout != 0 {
 		t = cc.t.afterFunc(readIdleTimeout, cc.healthCheck)
diff --git a/http2/write.go b/http2/write.go
index 33f61398a..6ff6bee7e 100644
--- a/http2/write.go
+++ b/http2/write.go
@@ -131,6 +131,16 @@ func (se StreamError) writeFrame(ctx writeContext) error {
 
 func (se StreamError) staysWithinBuffer(max int) bool { return frameHeaderLen+4 <= max }
 
+type writePing struct {
+	data [8]byte
+}
+
+func (w writePing) writeFrame(ctx writeContext) error {
+	return ctx.Framer().WritePing(false, w.data)
+}
+
+func (w writePing) staysWithinBuffer(max int) bool { return frameHeaderLen+len(w.data) <= max }
+
 type writePingAck struct{ pf *PingFrame }
 
 func (w writePingAck) writeFrame(ctx writeContext) error {
diff --git a/route/address.go b/route/address.go
index 5443d6722..bae63003f 100644
--- a/route/address.go
+++ b/route/address.go
@@ -170,20 +170,37 @@ func (a *Inet6Addr) marshal(b []byte) (int, error) {
 
 // parseInetAddr parses b as an internet address for IPv4 or IPv6.
 func parseInetAddr(af int, b []byte) (Addr, error) {
+	const (
+		off4 = 4 // offset of in_addr
+		off6 = 8 // offset of in6_addr
+	)
 	switch af {
 	case syscall.AF_INET:
-		if len(b) < sizeofSockaddrInet {
+		if len(b) < (off4+1) || len(b) < int(b[0]) {
 			return nil, errInvalidAddr
 		}
+		sockAddrLen := int(b[0])
 		a := &Inet4Addr{}
-		copy(a.IP[:], b[4:8])
+		n := off4 + 4
+		if sockAddrLen < n {
+			n = sockAddrLen
+		}
+		copy(a.IP[:], b[off4:n])
 		return a, nil
 	case syscall.AF_INET6:
-		if len(b) < sizeofSockaddrInet6 {
+		if len(b) < (off6+1) || len(b) < int(b[0]) {
 			return nil, errInvalidAddr
 		}
-		a := &Inet6Addr{ZoneID: int(nativeEndian.Uint32(b[24:28]))}
-		copy(a.IP[:], b[8:24])
+		sockAddrLen := int(b[0])
+		n := off6 + 16
+		if sockAddrLen < n {
+			n = sockAddrLen
+		}
+		a := &Inet6Addr{}
+		if sockAddrLen == sizeofSockaddrInet6 {
+			a.ZoneID = int(nativeEndian.Uint32(b[24:28]))
+		}
+		copy(a.IP[:], b[off6:n])
 		if a.IP[0] == 0xfe && a.IP[1]&0xc0 == 0x80 || a.IP[0] == 0xff && (a.IP[1]&0x0f == 0x01 || a.IP[1]&0x0f == 0x02) {
 			// KAME based IPv6 protocol stack usually
 			// embeds the interface index in the
diff --git a/route/address_darwin_test.go b/route/address_darwin_test.go
index b819183a7..0b5c72d1d 100644
--- a/route/address_darwin_test.go
+++ b/route/address_darwin_test.go
@@ -42,6 +42,60 @@ var parseAddrsOnDarwinLittleEndianTests = []parseAddrsOnDarwinTest{
 			nil,
 		},
 	},
+	{
+		syscall.RTA_DST | syscall.RTA_GATEWAY | syscall.RTA_NETMASK,
+		parseKernelInetAddr,
+		[]byte{
+			0x10, 0x02, 0x00, 0x00, 0x64, 0x71, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+			0x14, 0x12, 0x21, 0x00, 0x01, 0x08, 0x00, 0x00,
+			0x75, 0x74, 0x75, 0x6e, 0x34, 0x33, 0x31, 0x39,
+			0x00, 0x00, 0x00, 0x00,
+
+			0x06, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00,
+		},
+		[]Addr{
+			&Inet4Addr{IP: [4]byte{100, 113, 0, 0}},
+			&LinkAddr{Index: 33, Name: "utun4319"},
+			&Inet4Addr{IP: [4]byte{255, 255, 0, 0}},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+	},
+	// route -n add -inet6 fd84:1b4e:6281:: -prefixlen 48 fe80::f22f:4bff:fe09:3bff%utun4319
+	// gw fe80:0000:0000:0000:f22f:4bff:fe09:3bff
+	{
+		syscall.RTA_DST | syscall.RTA_GATEWAY | syscall.RTA_NETMASK,
+		parseKernelInetAddr,
+		[]byte{
+			0x1c, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0xfd, 0x84, 0x1b, 0x4e, 0x62, 0x81, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00,
+
+			0x1c, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0xfe, 0x80, 0x00, 0x21, 0x00, 0x00, 0x00, 0x00,
+			0xf2, 0x2f, 0x4b, 0xff, 0xfe, 0x09, 0x3b, 0xff,
+			0x00, 0x00, 0x00, 0x00,
+
+			0x0e, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00,
+		},
+		[]Addr{
+			&Inet6Addr{IP: [16]byte{ 0xfd, 0x84, 0x1b, 0x4e, 0x62, 0x81 }},
+			&Inet6Addr{IP: [16]byte{ 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x2f, 0x4b, 0xff, 0xfe, 0x09, 0x3b, 0xff }, ZoneID: 33},
+			&Inet6Addr{IP: [16]byte{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,}},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+	},
 }
 
 func TestParseAddrsOnDarwin(t *testing.T) {
diff --git a/websocket/websocket.go b/websocket/websocket.go
index 923a5780e..ac76165ce 100644
--- a/websocket/websocket.go
+++ b/websocket/websocket.go
@@ -8,7 +8,7 @@
 // This package currently lacks some features found in an alternative
 // and more actively maintained WebSocket package:
 //
-//	https://pkg.go.dev/nhooyr.io/websocket
+//	https://pkg.go.dev/github.com/coder/websocket
 package websocket // import "golang.org/x/net/websocket"
 
 import (