I crawled the Bitcoin network to record the minimum relay fee advertised by reachable nodes through the FEEFILTER message.
The scan used a modified version of virtu’s p2p-crawler which connects to every node, waits up to three minutes for a FEEFILTER message, and records the result. If no FEEFILTER message is received within the timeout the node is listed as “No FEEFILTER sent.”
Only nodes that accept inbound connections are included, and the results are based only on what each node advertises in its FEEFILTER message. I don’t think nodes have a reason to fake this field, but I suppose it’s possible, and I did not perform additional checks such as sending test transactions or monitoring relays.
Two full scans were run on 10/09 and 15/09.
Networks covered
| Network | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| i2p | 2,980 (10.6%) | 3,081 (10.8%) |
| ipv4 | 9,020 (32.0%) | 8,681 (30.4%) |
| ipv6 | 2,002 (7.1%) | 2,008 (7.0%) |
| onion_v3 | 14,216 (50.4%) | 14,769 (51.8%) |
Reported minimum relay fees
| MinRelayFee | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| 1000 | 25,125 (89.0%) | 24,695 (86.5%) |
| No FEEFILTER sent | 2,135 (7.6%) | 2,331 (8.2%) |
| 100 | 569 (2.0%) | 1105 (3.9%) |
| 9170997 | 84 (0.3%) | 73 (0.3%) |
| 1 | 81 (0.3%) | 91 (0.3%) |
(Because categories with very few nodes were excluded, the percentages do not add up to exactly 100%.)
Network-by-Network Breakdown
i2p
| MinRelayFee | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| 1000 | 2,862 (96.0%) | 2,844 (93.6%) |
| 100 | 61 (2.0%) | 143 (4.6%) |
| No FEEFILTER sent | 20 (0.7%) | 21 (0.7%) |
IPv4
| MinRelayFee | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| 1000 | 6,879 (76.3%) | 6,295 (72.5%) |
| No FEEFILTER sent | 1,758 (19.5%) | 1,924 (22.2%) |
| 100 | 223 (2.5%) | 307 (3.5%) |
IPv6
| MinRelayFee | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| 1000 | 1,685 (84.2%) | 1,639 (81.6%) |
| No FEEFILTER sent | 221 (11.0%) | 239 (11.9%) |
| 100 | 59 (2.9%) | 69 (3.4%) |
onion_v3
| MinRelayFee | Nodes 10/09 | Nodes 15/09 |
|---|---|---|
| 1000 | 13,699 (96.4%) | 13,877 (94.0%) |
| 100 | 226 (1.6%) | 586 (4.0%) |
| No FEEFILTER sent | 136 (1.0%) | 147 (1.0%) |
Open questions
- I was surprised to see that a large share of IPv4 nodes didn’t send a
FEEFILTER. Peter Todd suggested these might be spy nodes. When I checked the IP addresses, I noticed several clusters of about 50 nodes sharing the same subnet, though I did not investigate further. The 9170997 entries are a bit odd… I connected to a few of those nodes with Bitcoin Core and checkedEDIT: See 0xb10c’s explanation here [https://delvingbitcoin.org/t/measuring-minrelaytxfee-across-the-bitcoin-network/1989/3?u=danielabrozzoni]minfeefilteringetpeerinfoto make sure the crawler wasn’t wrongly parsing messages. The value really is what they’re advertising, but I have no idea why… if anyone has a theory, I’d love to hear it.
Acknowledgments
The idea for this post was inspired by tweets from Murch (original tweet, correction)
Thanks to Peter Todd for a few pointers and a quick sanity check. All remaining errors are my fault :)