[bug]: No bootstrap nodes for Bitcoin testnet4 ?

[pbraun9]

LND here is up against testnet4 but shows following error

2025-06-13 21:45:52.780 [INF] DISC: Attempting to bootstrap with: Authenticated Channel Graph
2025-06-13 21:45:52.780 [ERR] SRVR: Unable to retrieve initial bootstrap peers: no addresses found

I am behind multiple NATs but that shouldn't prevent me from reaching the LND seeding nodes right? I can reach some LND seeding nodes on 9735/tcp against test.nodes.lightning.directory. Question is, are those only for legacy testnet or also offering testnet4? Are there testnet4 LND seeding public nodes?

I have bitcoind as backend and it's in sync (progress=1).

lnd version 0.19.0-beta commit=v0.19.0-beta Ubuntu jammy -- Linux alpha15 5.15.0-139-generic #149-Ubuntu SMP Fri Apr 11 22:06:13 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux Bitcoin Core version v28.1.0

Here's my config for Bitcoind

testnet4=1
txindex=1
coinstatsindex=1
blockfilterindex=1

server=1
daemon=1
zmqpubrawblock=tcp://192.168.0.x:28332
zmqpubrawtx=tcp://192.168.0.x:28333
rpcuser=REPLACEME
rpcpassword=REPLACEME

and for LND

[Application Options]
# trace debug info warn error critical
debuglevel=info
listen=0.0.0.0:9735

# advertise your node
#externalip=x.x.x.x

[Bitcoin]
bitcoin.active=true
bitcoin.testnet4=true
bitcoin.node=bitcoind

[Bitcoind]
bitcoind.rpchost=127.0.0.1
bitcoind.rpcuser=REPLACEME
bitcoind.rpcpass=REPLACEME
bitcoind.zmqpubrawblock=tcp://192.168.0.x:28332
bitcoind.zmqpubrawtx=tcp://192.168.0.x:28333

[calvinrzachman]

The current lightning seed service doesn't support testnet4. We're making some deployment changes to the service and plan to include testnet4 support along side those changes. Should have that added relatively soon. Can ping back here when it's operational.

[calvinrzachman]

@pbraun9 We got a new version of the lightning seed service up and running with support for both signet and testnet4.

Best I have been able to tell so far, the testnet4 Lightning Network is still very much in its infancy:

lnd-lseed-testnet4-fcd9d76d7-lj9ng:/# lncli getnetworkinfo
{
    "graph_diameter":  5,
    "avg_out_degree":  2.727272727272727,
    "max_out_degree":  5,
    "num_nodes":  11,
    "num_channels":  15,
    "total_network_capacity":  "61000000",
...

You can observe a few candidate bootstrap peers manually via the query dig test4.nodes.lightning.wiki SRV.

The plan is to update lnd to use this new lightning seed service, but until that's done you'll need to update your lnd.conf file to point your node at the new service as demonstrated here.

Or, with a bit more involvement, you could try to manually add the peers returned via the query above (bech32 decode to recover the compressed node ID public key, lncli connect...):

# Obtain set of candidate peers from lseed service
➜ ✗ dig test4.nodes.lightning.wiki SRV
...
;; ANSWER SECTION:
test4.nodes.lightning.wiki. 60	IN	SRV	10 10 9735 ln1qfxxu8kaztc8jtgvrhw6827xut77d0uf72zguqx03449374mdsatvzwjnx7.test4.nodes.lightning.wiki.
test4.nodes.lightning.wiki. 60	IN	SRV	10 10 49735 ln1qdcnhtju4x4c7qvk3hfu0j9wuul8n8y52krxkm2n6fh82h88h6fksgy0yq8.test4.nodes.lightning.wiki.

# Obtain network address of a peer from lseed service:
➜ ✗ dig ln1qfxxu8kaztc8jtgvrhw6827xut77d0uf72zguqx03449374mdsatvzwjnx7.test4.nodes.lightning.wiki
...
;; ANSWER SECTION:
ln1qfxxu8kaztc8jtgvrhw6827xut77d0uf72zguqx03449374mdsatvzwjnx7.test4.nodes.lightning.wiki. 60 IN A 81.17.102.136

 # Convert node hostname to node ID public key:
ln1qfxxu8kaztc8jtgvrhw6827xut77d0uf72zguqx03449374mdsatvzwjnx7 --> 024c6e1edd12f0792d0c1ddda3abc6e2fde6bf89f2848e00cf8d6a58fabb6c3ab6

[calvinrzachman]

Looks like v0.19.2-beta will use the new lightning seed bootstrap service, so the simplest option would be to just run the new release when it drops 😄

[saubyk]

Closing based on the above comment, should be resolved with lnd v0.19.2