Lightning: https://1ml.com/ does not display Time Lock Delta ; Min HTLC ;Base Fee ;Fee Rate

[Chozowarrior]

All of my channels do not display Time Lock Delta ; Min HTLC ;Base Fee & Fee Rate. Is this a know issue with the 1ml.com website our is this an issue within my c-lightning node?

[cdecker]

Do you have an example for this? Generally speaking you should contact the operator of 1ml, since they might be in a better position to help you debug the situation.

[Chozowarrior]

An example would be https://1ml.com/channel/602150841537134592 with node 2. Below are the cli details for this channel. I will also address the issue with 1ml.
{
"channels": [
{
"source": "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276",
"destination": "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6",
"short_channel_id": "547653:774:0",
"public": true,
"satoshis": 4000000,
"message_flags": 0,
"channel_flags": 0,
"flags": 0,
"active": true,
"last_update": 1541106082,
"base_fee_millisatoshi": 1000,
"fee_per_millionth": 1,
"delay": 144
},
{
"source": "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6",
"destination": "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276",
"short_channel_id": "547653:774:0",
"public": true,
"satoshis": 4000000,
"message_flags": 1,
"channel_flags": 1,
"flags": 257,
"active": true,
"last_update": 1540842655,
"base_fee_millisatoshi": 950,
"fee_per_millionth": 1,
"delay": 144
}
]
}

[cdecker]

That looks suspiciously like 1ml is not receiving a channel_update, I also can't find one in my gossipd, so maybe this channel is currently not sending updates? Reconnecting to the peer should push the channel_update again.

[Chozowarrior]

Trying to run the connect command again does not seem to make a difference. Also this is the same for all the 52 public channels I am running. How can I check whether my channel is sending updates or not? At least funds are occasionally running through some channels.

[cdecker]

Ok, looking through the output of my own listchannels I get the following:

$ lcli listchannels | jq '.channels[] | select(.source == "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6") | select(.destination == "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276")'
{
  "source": "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6",
  "destination": "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276",
  "short_channel_id": "549833:2282:1",
  "public": true,
  "satoshis": 4600000,
  "message_flags": 1,
  "channel_flags": 1,
  "flags": 257,
  "active": true,
  "last_update": 1542054323,
  "base_fee_millisatoshi": 987,
  "fee_per_millionth": 1,
  "delay": 144
}
$ lcli listchannels | jq '.channels[] | select(.destination == "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6") | select(.source == "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276")'
{
  "source": "02c69a0b4cb468660348d6d457d9212563ad08fb94d424395da6796fb74a13f276",
  "destination": "03a5927b64b1ea8657d5b770d61a3e2d0554fdb5d568773e0d6a92907913ca21f6",
  "short_channel_id": "549833:2282:1",
  "public": true,
  "satoshis": 4600000,
  "message_flags": 0,
  "channel_flags": 0,
  "flags": 0,
  "active": true,
  "last_update": 1542052884,
  "base_fee_millisatoshi": 1000,
  "fee_per_millionth": 1,
  "delay": 144
}

The 257 in the channel flags got me to hunt down what might have happened. It turns out that 1ml does not handle flags correctly. It appears that they do not handle the case that the optional high bits are set. They should really fix that asap...

[niftynei]

To add some context, c-lightning now sends the htlc_maximum_msat field in channel_updates which is signaled via the message_flag being set to one.

[Chozowarrior]

Thanks for finding this! I will give them the information provided by you. However before I have not yet received any feedback from 1ml when raising the issue.

[firewire0202]

@Chozowarrior did 1ML ever get back to you on this? My c-lightning node is experiencing the same issue.

[Chozowarrior]

@firewire0202 yes I got confirmation from their side that they will look into it.

[Chozowarrior]

This has now been fixed within 1ML