Align p2p knobs with Lotus

[LesnyRumcajs]

Summary

rust-libp2p ships with different defaults than Lotus and its go-libp2p

This needs to be investigated; we probably want to align with Lotus, but there might be some additional considerations due to somehow different behaviour or feature set of both both libp2p implementations.

Claude-analysed discrepancies

Note ⏬ was generated by AI so it's just a rough overview of potential misalignment. There might be more (or less) knobs to turn.

Captured 2026-09-14, during the rust-libp2p 0.56 → 0.57 upgrade.

Sources, all read at a pinned revision:

• Forest — src/libp2p/behaviour.rs (build_gossipsub), rust defaults where unset
• Lotus — node/modules/lp2p/pubsub.go init(), which applies to every Lotus node; italic cells are not overridden and inherit the go default
• rust — libp2p-gossipsub 0.50.0, src/config.rs + src/protocol.rs
• go — go-libp2p-pubsub @ 892d7aaf6b8952c1ebfb540901b9a5656615d949, gossipsub.go var block + pubsub.go
• js — @chainsafe/libp2p-gossipsub @ 5b1abf362b496b1e90096276e9ac63897524a6a1, src/constants.ts + src/index.ts opts block + src/message/decodeRpc.ts

Bold marks a divergence from Lotus, which is the Filecoin network's real baseline.

Mesh / overlay

concept	rust knob	Forest	Lotus	rust	go	js
mesh degree D	mesh_n	6	8	6	6	6
mesh low Dlo	mesh_n_low	5	6	5	5	4
mesh high Dhi	mesh_n_high	12	12	12	12	12
outbound min Dout	mesh_outbound_min	2	3	2	2	2
score-retained Dscore	retain_scores	4	6	4	4	4
lazy gossip Dlazy	gossip_lazy	6	12	6	6	6
gossip factor	gossip_factor	0.25	0.1	0.25	0.25	0.25
PX prune peers	prune_peers	0	16	0	16	16

Timing / cache

concept	rust knob	Forest	Lotus	rust	go	js
mcache history	history_length	5	10	5	5	5
gossip window	history_gossip	3	3	3	3	3
IWANT followup	iwant_followup_time	3s	5s	3s	3s	3s
seen-message TTL	duplicate_cache_time	60s	120s	60s	120s	120s
heartbeat interval	heartbeat_interval	1s	1s	1s	1s	1s
heartbeat initial delay	heartbeat_initial_delay	5s	100ms	5s	100ms	100ms
fanout TTL	fanout_ttl	60s	60s	60s	60s	60s
prune backoff	prune_backoff	60s	60s	60s	60s	60s
unsubscribe backoff	unsubscribe_backoff	10s	10s	10s	10s	10s
graft flood threshold	graft_flood_threshold	10s	10s	10s	10s	10s
opportunistic graft ticks / peers	opportunistic_graft_ticks / _peers	60 / 2	60 / 2	60 / 2	60 / 2	60 / 2
direct connect ticks	check_explicit_peers_ticks	300	300	300	300	300

Limits

concept	rust knob	Forest	Lotus	rust	go	js
max RPC bytes	max_transmit_size	1 MiB	1 MiB	64 KiB	1 MiB	4 MiB
max control bytes	max_control_message_size	512 KiB	512 KiB	16 KiB	512 KiB	∞
publish count / RPC	max_publish_messages	5000	none	500 enforced	none	∞
IHAVE ids sent	max_control_messages_sent	5000	5000	5000	5000	5000
IHAVE msgs / heartbeat	max_ihave_messages_heartbeat	10	10	10	10	10
gossip retransmission	gossip_retransimission	3	3	3	3	3
IDONTWANT min size	idontwant_message_size_threshold	1000	1024	1000	1024	512
flood publish	flood_publish	true	true	true	false	true
signature policy	validation_mode	Strict	StrictSign	Strict	StrictSign	StrictSign

Peer score thresholds already match Lotus exactly (-500 / -1000 / -2500 / 1000 / 3.5), see src/libp2p/gossip_params.rs.

Completion Criteria

• investigate the defaults between two implementations and decide which constants should be aligned - it might be that we have an objectively better setting somewhere than Lotus or go-libp2p
• Some mismatches might be worth raising to the rust-libp2p maintainers.

Additional Links & Resources