From rusty at blockstream.com  Fri Jun 30 19:22:40 2023
From: rusty at blockstream.com (Rusty Russell)
Date: Sat, 01 Jul 2023 04:52:40 +0930
Subject: [Lightning-dev] BOLT cleanup: removing features, assuming others
Message-ID: <87v8f4ycu7.fsf@rustcorp.com.au>

https://github.com/lightning/bolts/pull/1092

 02-peer-protocol.md  |   74 ++-------
 03-transactions.md   |  389 ---------------------------------------------------
 05-onchain.md        |   17 --
 07-routing-gossip.md |   52 +-----
 09-features.md       |   30 +--
 5 files changed, 48 insertions(+), 514 deletions(-)

Simplicity FTW.  This PR proposes to start ignoring
(and thus, simply assuming) various features, based on recent releases
and scanning node announcments:

Removed:

* initial_routing_sync (only had an effect if gossip_queries not supported)
* option_anchor_outputs (only supported by older experimental-only CLN builds)

I looked at all node_announcements on my node. There are 449 nodes apparently running a 4-year-old LND version (features hex 2200), which have 3+ year old channels. @Roasbeef points out that they already will have their channel_updates ignored due to lack of htlc_maximum_msat which is now required by LND and CLN, at least).

Features you can now assume (you should probably still set it for now, but you can stop checking it).

* var_onion_optin (all but 6 nodes)
* gossip_queries (all but 11 nodes)
* option_data_loss_protect (all but 11 nodes)
* option_static_remotekey (all but 16 nodes)

Cheers!
Rusty.