diff --git a/cmd/f3/manifest.go b/cmd/f3/manifest.go
index 600a1e51..9bde7176 100644
--- a/cmd/f3/manifest.go
+++ b/cmd/f3/manifest.go
@@ -125,7 +125,7 @@ var manifestServeCmd = cli.Command{
 		&cli.DurationFlag{
 			Name:  "publishInterval",
 			Usage: "The interval at which manifest is published on pubsub.",
-			Value: 20 * time.Second,
+			Value: 2 * pubsub.TimeCacheDuration,
 		},
 	},
 
@@ -205,7 +205,11 @@ var manifestServeCmd = cli.Command{
 			return fmt.Errorf("loading initial manifest: %w", err)
 		}
 
-		pubSub, err := pubsub.NewGossipSub(c.Context, host, pubsub.WithPeerExchange(true))
+		pubSub, err := pubsub.NewGossipSub(c.Context, host,
+			pubsub.WithPeerExchange(true),
+			pubsub.WithFloodPublish(true),
+			pubsub.WithPeerScore(PubsubPeerScoreParams, PubsubPeerScoreThresholds),
+		)
 		if err != nil {
 			return fmt.Errorf("initialzing pubsub: %w", err)
 		}
diff --git a/cmd/f3/observer.go b/cmd/f3/observer.go
index bfe7bbff..6bfa958d 100644
--- a/cmd/f3/observer.go
+++ b/cmd/f3/observer.go
@@ -17,6 +17,7 @@ import (
 
 	"github.com/filecoin-project/go-f3/cmd/f3/msgdump"
 	"github.com/filecoin-project/go-f3/gpbft"
+	"github.com/filecoin-project/go-f3/internal/psutil"
 	"github.com/filecoin-project/go-f3/manifest"
 	leveldb "github.com/ipfs/go-ds-leveldb"
 	logging "github.com/ipfs/go-log/v2"
@@ -152,7 +153,11 @@ var observerCmd = cli.Command{
 		// Connect to bootstrappers once as soon as we start.
 		connectToBootstrappers()
 
-		pubSub, err := pubsub.NewGossipSub(c.Context, host, pubsub.WithPeerExchange(true))
+		pubSub, err := pubsub.NewGossipSub(c.Context, host,
+			pubsub.WithPeerExchange(true),
+			pubsub.WithFloodPublish(true),
+			pubsub.WithPeerScore(PubsubPeerScoreParams, PubsubPeerScoreThresholds),
+		)
 		if err != nil {
 			return fmt.Errorf("initialzing pubsub: %w", err)
 		}
@@ -241,10 +246,13 @@ func observeManifest(ctx context.Context, manif *manifest.Manifest, pubSub *pubs
 		return fmt.Errorf("registering topic validator: %w", err)
 	}
 
-	topic, err := pubSub.Join(manif.PubSubTopic(), pubsub.WithTopicMessageIdFn(pubsub.DefaultMsgIdFn))
+	topic, err := pubSub.Join(manif.PubSubTopic(), pubsub.WithTopicMessageIdFn(psutil.GPBFTMessageIdFn))
 	if err != nil {
 		return fmt.Errorf("joining topic: %w", err)
 	}
+	if err := topic.SetScoreParams(psutil.PubsubTopicScoreParams); err != nil {
+		return fmt.Errorf("failed to set topic params: %w", err)
+	}
 
 	sub, err := topic.Subscribe()
 	if err != nil {
diff --git a/cmd/f3/pusub.go b/cmd/f3/pusub.go
index d0671159..32e34106 100644
--- a/cmd/f3/pusub.go
+++ b/cmd/f3/pusub.go
@@ -4,6 +4,7 @@ import (
 	"time"
 
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	"github.com/libp2p/go-libp2p/core/peer"
 )
 
 func init() {
@@ -20,3 +21,45 @@ func init() {
 	pubsub.GossipSubHistoryLength = 10
 	pubsub.GossipSubGossipFactor = 0.1
 }
+
+// Borrowed from lotus
+var PubsubPeerScoreParams = &pubsub.PeerScoreParams{
+	AppSpecificScore:  func(p peer.ID) float64 { return 0 },
+	AppSpecificWeight: 1,
+
+	// This sets the IP colocation threshold to 5 peers before we apply penalties
+	IPColocationFactorThreshold: 5,
+	IPColocationFactorWeight:    -100,
+	IPColocationFactorWhitelist: nil,
+
+	// P7: behavioural penalties, decay after 1hr
+	BehaviourPenaltyThreshold: 6,
+	BehaviourPenaltyWeight:    -10,
+	BehaviourPenaltyDecay:     pubsub.ScoreParameterDecay(time.Hour),
+
+	DecayInterval: pubsub.DefaultDecayInterval,
+	DecayToZero:   pubsub.DefaultDecayToZero,
+
+	// this retains non-positive scores for 6 hours
+	RetainScore: 6 * time.Hour,
+
+	// topic parameters
+	Topics: make(map[string]*pubsub.TopicScoreParams),
+}
+
+var PubsubPeerScoreThresholds = &pubsub.PeerScoreThresholds{
+	GossipThreshold:             GossipScoreThreshold,
+	PublishThreshold:            PublishScoreThreshold,
+	GraylistThreshold:           GraylistScoreThreshold,
+	AcceptPXThreshold:           AcceptPXScoreThreshold,
+	OpportunisticGraftThreshold: OpportunisticGraftScoreThreshold,
+}
+
+// Borrowed from lotus
+const (
+	GossipScoreThreshold             = -500
+	PublishScoreThreshold            = -1000
+	GraylistScoreThreshold           = -2500
+	AcceptPXScoreThreshold           = 1000
+	OpportunisticGraftScoreThreshold = 3.5
+)
diff --git a/f3_test.go b/f3_test.go
index 01fca7c6..3342f563 100644
--- a/f3_test.go
+++ b/f3_test.go
@@ -11,6 +11,7 @@ import (
 	"github.com/filecoin-project/go-f3/ec"
 	"github.com/filecoin-project/go-f3/gpbft"
 	"github.com/filecoin-project/go-f3/internal/clock"
+	"github.com/filecoin-project/go-f3/internal/psutil"
 	"github.com/filecoin-project/go-f3/manifest"
 	"github.com/filecoin-project/go-f3/sim/signing"
 
@@ -25,7 +26,13 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-const ManifestSenderTimeout = 30 * time.Second
+func init() {
+	// Hash-based deduplication breaks fast rebroadcast, even if we set the time window to be
+	// really short because gossipsub has a minimum 1m cache scan interval.
+	psutil.GPBFTMessageIdFn = pubsub.DefaultMsgIdFn
+}
+
+var ManifestSenderTimeout = 30 * time.Second
 
 func TestF3Simple(t *testing.T) {
 	t.Parallel()
diff --git a/host.go b/host.go
index 9aad9fb3..d8e8f485 100644
--- a/host.go
+++ b/host.go
@@ -13,6 +13,7 @@ import (
 	"github.com/filecoin-project/go-f3/ec"
 	"github.com/filecoin-project/go-f3/gpbft"
 	"github.com/filecoin-project/go-f3/internal/clock"
+	"github.com/filecoin-project/go-f3/internal/psutil"
 	"github.com/filecoin-project/go-f3/manifest"
 	"go.opentelemetry.io/otel/metric"
 
@@ -329,11 +330,17 @@ func (h *gpbftRunner) setupPubsub() error {
 	// Force the default (sender + seqno) message de-duplication mechanism instead of hashing
 	// the message (as lotus does) as we need to be able to re-broadcast duplicate messages with
 	// the same content.
-	topic, err := h.pubsub.Join(pubsubTopicName, pubsub.WithTopicMessageIdFn(pubsub.DefaultMsgIdFn))
+	topic, err := h.pubsub.Join(pubsubTopicName, pubsub.WithTopicMessageIdFn(psutil.GPBFTMessageIdFn))
 	if err != nil {
 		return fmt.Errorf("could not join on pubsub topic: %s: %w", pubsubTopicName, err)
 	}
+
+	if err := topic.SetScoreParams(psutil.PubsubTopicScoreParams); err != nil {
+		log.Infow("failed to set topic score params", "error", err)
+	}
+
 	h.topic = topic
+
 	return nil
 }
 
diff --git a/internal/psutil/psutil.go b/internal/psutil/psutil.go
new file mode 100644
index 00000000..bd5060ac
--- /dev/null
+++ b/internal/psutil/psutil.go
@@ -0,0 +1,97 @@
+package psutil
+
+import (
+	"encoding/binary"
+	"time"
+
+	"golang.org/x/crypto/blake2b"
+
+	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	pubsub_pb "github.com/libp2p/go-libp2p-pubsub/pb"
+)
+
+var ManifestMessageIdFn = pubsubMsgIdHashDataAndSender
+var GPBFTMessageIdFn = pubsubMsgIdHashData
+
+// Generate a pubsub ID from the message topic + data.
+func pubsubMsgIdHashData(m *pubsub_pb.Message) string {
+	hasher, err := blake2b.New256(nil)
+	if err != nil {
+		panic("failed to construct hasher")
+	}
+
+	topic := []byte(m.GetTopic())
+	if err := binary.Write(hasher, binary.BigEndian, uint32(len(topic))); err != nil {
+		panic(err)
+	}
+	if _, err := hasher.Write(topic); err != nil {
+		panic(err)
+	}
+
+	hash := blake2b.Sum256(m.Data)
+	return string(hash[:])
+}
+
+// Generate a pubsub ID from the message topic + sender + data.
+func pubsubMsgIdHashDataAndSender(m *pubsub_pb.Message) string {
+	hasher, err := blake2b.New256(nil)
+	if err != nil {
+		panic("failed to construct hasher")
+	}
+
+	topic := []byte(m.GetTopic())
+	if err := binary.Write(hasher, binary.BigEndian, uint32(len(topic))); err != nil {
+		panic(err)
+	}
+	if _, err := hasher.Write(topic); err != nil {
+		panic(err)
+	}
+	if err := binary.Write(hasher, binary.BigEndian, uint32(len(m.From))); err != nil {
+		panic(err)
+	}
+	if _, err := hasher.Write(m.From); err != nil {
+		panic(err)
+	}
+
+	hash := blake2b.Sum256(m.Data)
+	return string(hash[:])
+}
+
+// Borrowed from lotus
+var PubsubTopicScoreParams = &pubsub.TopicScoreParams{
+	// expected > 400 msgs/second on average.
+	//
+	TopicWeight: 0.1, // max cap is 5, single invalid message is -100
+
+	// 1 tick per second, maxes at 1 hour
+	// XXX
+	TimeInMeshWeight:  0.0002778, // ~1/3600
+	TimeInMeshQuantum: time.Second,
+	TimeInMeshCap:     1,
+
+	// NOTE: Gives weight to the peer that tends to deliver first.
+	// deliveries decay after 10min, cap at 100 tx
+	FirstMessageDeliveriesWeight: 0.5, // max value is 50
+	FirstMessageDeliveriesDecay:  pubsub.ScoreParameterDecay(10 * time.Minute),
+	FirstMessageDeliveriesCap:    100, // 100 messages in 10 minutes
+
+	// Mesh Delivery Failure is currently turned off for messages
+	// This is on purpose as the network is still too small, which results in
+	// asymmetries and potential unmeshing from negative scores.
+	// // tracks deliveries in the last minute
+	// // penalty activates at 1 min and expects 2.5 txs
+	// MeshMessageDeliveriesWeight:     -16, // max penalty is -100
+	// MeshMessageDeliveriesDecay:      pubsub.ScoreParameterDecay(time.Minute),
+	// MeshMessageDeliveriesCap:        100, // 100 txs in a minute
+	// MeshMessageDeliveriesThreshold:  2.5, // 60/12/2 txs/minute
+	// MeshMessageDeliveriesWindow:     10 * time.Millisecond,
+	// MeshMessageDeliveriesActivation: time.Minute,
+
+	// // decays after 5min
+	// MeshFailurePenaltyWeight: -16,
+	// MeshFailurePenaltyDecay:  pubsub.ScoreParameterDecay(5 * time.Minute),
+
+	// invalid messages decay after 1 hour
+	InvalidMessageDeliveriesWeight: -1000,
+	InvalidMessageDeliveriesDecay:  pubsub.ScoreParameterDecay(time.Hour),
+}
diff --git a/manifest/dynamic_manifest.go b/manifest/dynamic_manifest_provider.go
similarity index 88%
rename from manifest/dynamic_manifest.go
rename to manifest/dynamic_manifest_provider.go
index d08cef53..56c2378b 100644
--- a/manifest/dynamic_manifest.go
+++ b/manifest/dynamic_manifest_provider.go
@@ -7,7 +7,9 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"sync/atomic"
 
+	"github.com/filecoin-project/go-f3/internal/psutil"
 	"github.com/ipfs/go-datastore"
 	logging "github.com/ipfs/go-log/v2"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
@@ -20,7 +22,7 @@ var log = logging.Logger("f3/dynamic-manifest")
 
 var _ ManifestProvider = (*DynamicManifestProvider)(nil)
 
-const ManifestPubSubTopicName = "/f3/manifests/0.0.1"
+const ManifestPubSubTopicName = "/f3/manifests/0.0.2"
 
 // DynamicManifestProvider is a manifest provider that allows
 // the manifest to be changed at runtime.
@@ -35,6 +37,7 @@ type DynamicManifestProvider struct {
 
 	initialManifest *Manifest
 	manifestChanges chan *Manifest
+	sequenceNumber  atomic.Uint64
 }
 
 // ManifestUpdateMessage updates the GPBFT manifest.
@@ -96,23 +99,24 @@ func (m *DynamicManifestProvider) Start(startCtx context.Context) error {
 		return err
 	}
 
-	// Force the default (sender + seqno) message de-duplication mechanism instead of hashing
-	// the message (as lotus does) as validation depends on the sender, not the contents of the
-	// message.
-	manifestTopic, err := m.pubsub.Join(ManifestPubSubTopicName, pubsub.WithTopicMessageIdFn(pubsub.DefaultMsgIdFn))
+	// Use the message hash as the message ID to reduce the chances of routing cycles. We ensure
+	// our rebroadcast interval is greater than our cache timeout.
+	manifestTopic, err := m.pubsub.Join(ManifestPubSubTopicName, pubsub.WithTopicMessageIdFn(psutil.ManifestMessageIdFn))
 	if err != nil {
 		return fmt.Errorf("could not join manifest pubsub topic: %w", err)
 	}
 
+	if err := manifestTopic.SetScoreParams(psutil.PubsubTopicScoreParams); err != nil {
+		log.Infow("failed to set topic score params", "error", err)
+	}
+
 	manifestSub, err := manifestTopic.Subscribe()
 	if err != nil {
 		return fmt.Errorf("subscribing to manifest pubsub topic: %w", err)
 	}
 
-	var msgSeqNumber uint64
 	var currentManifest *Manifest
 	if mBytes, err := m.ds.Get(startCtx, latestManifestKey); errors.Is(err, datastore.ErrNotFound) {
-		msgSeqNumber = 0
 		currentManifest = m.initialManifest
 	} else if err != nil {
 		return fmt.Errorf("error while checking saved manifest")
@@ -123,7 +127,7 @@ func (m *DynamicManifestProvider) Start(startCtx context.Context) error {
 			return fmt.Errorf("decoding saved manifest: %w", err)
 		}
 
-		msgSeqNumber = update.MessageSequence
+		m.sequenceNumber.Store(update.MessageSequence)
 		currentManifest = &update.Manifest
 	}
 
@@ -164,10 +168,13 @@ func (m *DynamicManifestProvider) Start(startCtx context.Context) error {
 				continue
 			}
 
-			if update.MessageSequence <= msgSeqNumber {
-				log.Debugw("discarded manifest update", "newSeqNo", update.MessageSequence, "oldSeqNo", msgSeqNumber)
+			oldSeq := m.sequenceNumber.Load()
+
+			if update.MessageSequence <= oldSeq {
+				log.Debugw("discarded manifest update", "newSeqNo", update.MessageSequence, "oldSeqNo", oldSeq)
 				continue
 			}
+			m.sequenceNumber.Store(update.MessageSequence)
 
 			if err := update.Manifest.Validate(); err != nil {
 				log.Errorw("received invalid manifest, discarded", "error", err)
@@ -180,7 +187,6 @@ func (m *DynamicManifestProvider) Start(startCtx context.Context) error {
 			}
 
 			log.Infow("received manifest update", "seqNo", update.MessageSequence)
-			msgSeqNumber = update.MessageSequence
 
 			oldManifest := currentManifest
 			manifestCopy := update.Manifest
@@ -227,6 +233,11 @@ func (m *DynamicManifestProvider) registerTopicValidator() error {
 			return pubsub.ValidationReject
 		}
 
+		// Only allow the latest sequence number through.
+		if update.MessageSequence < m.sequenceNumber.Load() {
+			return pubsub.ValidationIgnore
+		}
+
 		// TODO: Any additional validation?
 		// Expect a sequence number that is over our current sequence number.
 		// Expect an BootstrapEpoch over the BootstrapEpoch of the current manifests?
diff --git a/manifest/manifest_sender.go b/manifest/dynamic_manifest_sender.go
similarity index 91%
rename from manifest/manifest_sender.go
rename to manifest/dynamic_manifest_sender.go
index 96dff4e5..8f8f5475 100644
--- a/manifest/manifest_sender.go
+++ b/manifest/dynamic_manifest_sender.go
@@ -7,6 +7,8 @@ import (
 	"time"
 
 	"github.com/filecoin-project/go-f3/internal/clock"
+	"github.com/filecoin-project/go-f3/internal/psutil"
+
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/peer"
@@ -43,10 +45,13 @@ func NewManifestSender(ctx context.Context, h host.Host, ps *pubsub.PubSub, firs
 	}
 
 	var err error
-	m.manifestTopic, err = m.pubsub.Join(ManifestPubSubTopicName, pubsub.WithTopicMessageIdFn(pubsub.DefaultMsgIdFn))
+	m.manifestTopic, err = m.pubsub.Join(ManifestPubSubTopicName, pubsub.WithTopicMessageIdFn(psutil.ManifestMessageIdFn))
 	if err != nil {
 		return nil, fmt.Errorf("could not join on pubsub topic: %s: %w", ManifestPubSubTopicName, err)
 	}
+	if err := m.manifestTopic.SetScoreParams(psutil.PubsubTopicScoreParams); err != nil {
+		log.Infow("could not set topic score params", "error", err)
+	}
 
 	// Record one-off attributes about the sender for easier runtime debugging.
 	metrics.senderInfo.Record(ctx, 1, metric.WithAttributes(
diff --git a/manifest/manifest.go b/manifest/manifest.go
index e077a885..63a81602 100644
--- a/manifest/manifest.go
+++ b/manifest/manifest.go
@@ -324,7 +324,7 @@ func (m *Manifest) PubSubTopic() string {
 }
 
 func PubSubTopicFromNetworkName(nn gpbft.NetworkName) string {
-	return "/f3/granite/0.0.1/" + string(nn)
+	return "/f3/granite/0.0.2/" + string(nn)
 }
 
 func (m *Manifest) GpbftOptions() []gpbft.Option {
diff --git a/manifest/manifest_test.go b/manifest/manifest_test.go
index ca588da4..b4070671 100644
--- a/manifest/manifest_test.go
+++ b/manifest/manifest_test.go
@@ -111,7 +111,7 @@ func TestManifest_NetworkName(t *testing.T) {
 			require.True(t, strings.HasPrefix(gotDsPrefix, "/f3"))
 			require.True(t, strings.HasSuffix(gotDsPrefix, string(test.subject)))
 			gotPubSubTopic := m.PubSubTopic()
-			require.True(t, strings.HasPrefix(gotPubSubTopic, "/f3/granite/0.0.1/"))
+			require.True(t, strings.HasPrefix(gotPubSubTopic, "/f3/granite/0.0.2/"))
 			require.True(t, strings.HasSuffix(gotPubSubTopic, string(test.subject)))
 		})
 	}