Feeler connections are short-lived connection made to check that a node is alive, useful for test-before-evict, and for moving addresses from the new to the tried table.
We currently send a GETADDR message to feelers, but then disconnect before being able to receive a response. This GETADDR is not useful and can be removed.
I couldn't find any previous discussion about this, but I found PR #22777, that similarly made sure that we don't ask for tx relay to feelers.
I noticed this behavior on my peer-observer instance: I would see the number of sent GETADDR messages increase over time, but the number of ADDR messages with >100 addresses received (which are likely GETADDR responses and not self announcements relays) wouldn't increase as much. I later realized that it was my node opening feeler connections, sending a GETADDR, and closing the connection.
You can see the same behavior using this command - the node is making feeler connections, sending getaddr to them, closing before receiving the addr response:
~ ₿ tail -f ~/.bitcoin/debug.log | grep -E "(Making feeler connection|Added connection to|sending getaddr|feeler connection completed|Received addr: [0-9]{2,} addresses)"
2026-04-02T13:25:50Z [net] Making feeler connection to xyz.onion:8333
2026-04-02T13:26:06Z [net] Added connection to xyz.onion:8333 peer=27
2026-04-02T13:26:08Z [net] sending getaddr (0 bytes) peer=27
2026-04-02T13:26:08Z [net] feeler connection completed, disconnecting peer=27, peeraddr=xyz.onion:8333
On a node that accepts inbounds connections, this command can be used to see in the logs all the nodes that connected, sent a getaddr, and disconnected before receiving a reply. It is possible that these nodes connected to us as a feeler:
~ ₿ cat .bitcoin/debug.log | awk '
/received: getaddr/ {
split($0, a, "peer=")
got_getaddr[a[2]] = $0
}
/sending addr/ {
split($0, a, "peer=")
sent_addr[a[2]] = 1
}
/socket closed/ {
split($0, a, "peer=")
id = a[2]
if (id in got_getaddr && !(id in sent_addr)) {
print "possible feeler: " got_getaddr[id]
print " " $0
}
delete got_getaddr[id]
delete sent_addr[id]
}
'
possible feeler: 2026-04-01T21:45:13Z [net] received: getaddr (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] socket closed, disconnecting peer=2311974
possible feeler: 2026-04-02T00:18:58Z [net] received: getaddr (0 bytes) peer=2426389
2026-04-02T00:18:58Z [net] socket closed, disconnecting peer=2426389
...
Then, you can manually inspect one of them:
~ ₿ cat .bitcoin/debug.log | grep -E "peer=2311974"
2026-04-01T21:45:13Z [net] Added connection peer=2311974
2026-04-01T21:45:13Z [net] received: version (102 bytes) peer=2311974
2026-04-01T21:45:13Z [net] sending version (102 bytes) peer=2311974
2026-04-01T21:45:13Z [net] send version message: version 70016, blocks=943279, txrelay=0, peer=2311974
2026-04-01T21:45:13Z [net] sending wtxidrelay (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] sending sendaddrv2 (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] sending verack (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] receive version message: /Satoshi:27.0.0/: version 70016, blocks=943279, us=x.x.x.x:8333, txrelay=0, peer=2311974
2026-04-01T21:45:13Z [net] received: wtxidrelay (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] received: sendaddrv2 (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] received: verack (0 bytes) peer=2311974
2026-04-01T21:45:13Z New inbound v1 peer connected: version: 70016, blocks=943279, peer=2311974
2026-04-01T21:45:13Z [net] sending sendcmpct (9 bytes) peer=2311974
2026-04-01T21:45:13Z [net] sending ping (8 bytes) peer=2311974
2026-04-01T21:45:13Z [net] sending getheaders (1029 bytes) peer=2311974
2026-04-01T21:45:13Z [net] initial getheaders (943278) to peer=2311974 (startheight:943279)
2026-04-01T21:45:13Z [net] received: getaddr (0 bytes) peer=2311974
2026-04-01T21:45:13Z [net] Advertising address x.x.x.x:8333 to peer=2311974
2026-04-01T21:45:13Z [net] socket closed, disconnecting peer=2311974
2026-04-01T21:45:13Z [net] Resetting socket for peer=2311974
2026-04-01T21:45:13Z [net] sending addrv2 (24665 bytes) peer=2311974
2026-04-01T21:45:13Z [net] Cleared nodestate for peer=2311974