What the developer wrote
Authored by Bastien Teinturier
Allow high remote `dust_limit_satoshis` (#3215)
Now that we only accept anchor output channels and beyong, we should
let our peers use high `dust_limit_satoshis` values to ensure that the
transaction outputs are economically spendable.
We can't yet raise our `dust_limit_satoshis`: we must first accept high
values, and in the next release (and once other implementations support
it as well), then we'll be able to increase our default value.
What changed, and why it matters
This commit raises the maximum dust limit Eclair will accept from remote Lightning peers from 600 to 10,000 satoshis. Dust limits determine the smallest transaction output a channel will create. The change is framed as a forward-compatibility and economic-spendability improvement for newer 'anchor output' channels, not as a security fix. It does not change Eclair's own dust limit (still 546 satoshis).
Treat as a normal protocol-parameter tuning change. Review whether 10,000 satoshis is consistent with current BOLT specifications and peer implementation limits. Monitor for any follow-up commits that raise Eclair's own `dust-limit-satoshis`. No immediate security response is indicated by the commit content.
Security signals we found
Configuration change affecting channel output trimming policy
Dust limit directly influences UTXO creation and potential dust exposure
No input validation, cryptographic, or authorization change
No mention of CVE, vulnerability, bug, or exploit in commit or title
Evidence from the diff
The single-line configuration change increases max-remote-dust-limit-satoshis from 600 to 10000 in reference.conf. The commit message explains that with anchor output channels, on-chain feerate is no longer considered when trimming outputs, so a higher dust limit is needed to ensure outputs remain economically spendable. Eclair’s local dust-limit-satoshis remains 546. The change only affects what remote dust limits Eclair will accept during channel open/accept.
Changed components
eclair-core/src/main/resources/reference.confLightning channel dust-limit negotiationAnchor output channel output trimmingInspect captured patch +3 / −1
diff --git a/eclair-core/src/main/resources/reference.conf b/eclair-core/src/main/resources/reference.conf
index a6b7125..4d5634d 100644
--- a/eclair-core/src/main/resources/reference.conf
+++ b/eclair-core/src/main/resources/reference.conf
@@ -118,7 +118,9 @@ eclair {
}
dust-limit-satoshis = 546
- max-remote-dust-limit-satoshis = 600
+ // Starting with anchor outputs channels, the on-chain feerate is not taken into account when trimming outputs.
+ // We must thus use a high enough dust limit to ensure that the outputs can economically be spent on-chain.
+ max-remote-dust-limit-satoshis = 10000
htlc-minimum-msat = 1
// The following parameters apply to each HTLC direction (incoming or outgoing), which means that the maximum amount in flight will be at most twice what is set here.
// Note that our peer may use a lower value than ours, which would reduce the maximum amount in flight.
Why this scored 33/100
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