From 342ab552a3babba6c7c8e692a90ad50d6783b623 Mon Sep 17 00:00:00 2001 From: t-bast Date: Wed, 15 Sep 2021 09:30:20 +0200 Subject: [PATCH] Add rationale for closing tx below dust Explain why we must force-close channels for which the closing tx doesn't meet bitcoin's default relay policies. --- 02-peer-protocol.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/02-peer-protocol.md b/02-peer-protocol.md index 84e0483f0..994a80523 100644 --- a/02-peer-protocol.md +++ b/02-peer-protocol.md @@ -695,6 +695,12 @@ to have a maximum feerate. It may want a minimum feerate, however, to ensure that the transaction propagates. It can always use CPFP later to speed up confirmation if necessary, so that minimum should be low. +It may happen that the closing transaction doesn't meet bitcoin's default relay +policies (e.g. when using a non-segwit shutdown script for an output below 546 +satoshis, which is possible if `dust_limit_satoshis` is below 546 satoshis). +No funds are at risk when that happens, but the channel must be force-closed as +the closing transaction will likely never reach miners. + ## Normal Operation Once both nodes have exchanged `funding_locked` (and optionally [`announcement_signatures`](07-routing-gossip.md#the-announcement_signatures-message)), the channel can be used to make payments via Hashed Time Locked Contracts.