<p>Most probable explanation for now : the channels who never routed betwen them before happened to route just after the change, but the sender did not know about the fee change yet</p>

CC BY-SA 4.0
2023-01-03T11:28:23.957Z
2023-01-03T11:28:23.957Z
bartoli
<p>Something strange just occurred on my LND node, making me think I don't understand something about lightning fees.</p>
<p>I have channels to A &amp; B, who only ever asked me to route transactions going to C.</p>
<p>Based on the assumption that the fee is calculated from the fee rates of the outbound channel of a route, I figured I could set the fees of the channels to A &amp; B to 0 (base + feerate) since they are never the outbound channel, so I never earn fees through them, so it incentivizes routes in the other way. Not earning me fees, but rebalancing the channels for free.</p>
<p>Minutes later, I got 4 routes between A to B. But to my surprise, those routes supposedly earnt me fees, according to RTL, corresponding to the feerate before i set it to 0.</p>
<p>How can this happen if I have set 0 fees for both channels? Could it be some kind of update issue, where the rest of the network thinks the channels are now free, but the updated fee is not yet applied? Or something else I don't understand?</p>

CC BY-SA 4.0
2023-01-02T16:15:28.990Z
There is a feerate relative to the amount sent and there is a flat base fee. Could you clarify whether you have set both to zero, or just one?
Murch
CC BY-SA 4.0
2023-01-03T08:48:36.413Z
Changing the fee on existing channels may take time to propagate. As the payments you mentioned happened soon ('minutes later'), is it possible that the sending A node acted still with the old fee setting? Afterall it's the sender who specifies all the fees for all the routing nodes upfront.
OptOut
<lightning-network-daemon><lightning-routing>
Lightning routing fees received between 2 channels with 0 feerate?
bartoli
# Lightning routing fees received between 2 channels with 0 feerate?

(Asked by: username_0 on 2023-01-02)

Something strange just occurred on my LND node, making me think I don't understand something about lightning fees.

I have channels to A & B, who only ever asked me to route transactions going to C.

Based on the assumption that the fee is calculated from the fee rates of the outbound channel of a route, I figured I could set the fees of the channels to A & B to 0 (base + feerate) since they are never the outbound channel, so I never earn fees through them, so it incentivizes routes in the other way. Not earning me fees, but rebalancing the channels for free.

Minutes later, I got 4 routes between A to B. But to my surprise, those routes supposedly earnt me fees, according to RTL, corresponding to the feerate before i set it to 0.

How can this happen if I have set 0 fees for both channels? Could it be some kind of update issue, where the rest of the network thinks the channels are now free, but the updated fee is not yet applied? Or something else I don't understand?

**Tags:** lightning-network-daemon, lightning-routing

> **Comments:**
> **username_1**: There is a feerate relative to the amount sent and there is a flat base fee. Could you clarify whether you have set both to zero, or just one?  
> **username_2**: Changing the fee on existing channels may take time to propagate. As the payments you mentioned happened soon ('minutes later'), is it possible that the sending A node acted still with the old fee setting? Afterall it's the sender who specifies all the fees for all the routing nodes upfront.  

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## 1 answers

### Answer by username_0 on 2023-01-03. Score: 1

Most probable explanation for now : the channels who never routed betwen them before happened to route just after the change, but the sender did not know about the fee change yet


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