net, doc: update I2P hardcoded seeds and docs for 22.0

[jonatack]

• Update the I2P seeds with the latest ones I can connect to (feedback welcome).

• Update the I2P doc with frequently asked and reported info: IBD speed and running with other networks.

[jonatack]

Some of the I2P addresses can be somewhat intermittent.

A few other addresses I have that seem to be less-often connectable recently:

22plzy5mqwz64iukd2hbsa5oo454iwkjko26tifi54ir4mbnpfea.b32.i2p -> edit: updated to new address, zhjaqw53flrpjvic3ieihzhhkmxedkoccynhowongdkviivtxbmq.b32.i2p
72l3ucjkuscrbiiepoehuwqgknyzgo7zuix5ty4puwrkyhtmnsga.b32.i2p
pjs7or2ctvteeo5tu4bwyrtydeuhqhvdprtujn4daxr75jpebjxa.b32.i2p
sedndhv5vpcgdmykyi5st4yqhdxl3hpdtglta4do435wupahhx6q.b32.i2p -> edit: can add
vnqix5uljfwssvzbexzjeuoehjujtw4iqftiu34nbvig64kkmnla.b32.i2p
wxgpc5mtv5dk2kzpgqz7ybjtmumrnavfoa36o4mas4ksc3owqgya.b32.i2p

Feedback and additional addresses welcome.

[jonatack]

(Don't merge yet. People are replying offline regarding their I2P nodes, will update.)

[vasild]

ACK d2dffd5

No changes by:

contrib/seeds/generate-seeds.py contrib/seeds > src/chainparamsseeds.h

(so, src/chainparamsseeds.h has been generated from contrib/seeds indeed).

I tried to connect to all I2P nodes from the seeds and compared the seeds with the nodes I am currently connected to:

#  get I2P seeds
grep "b32\.i2p" contrib/seeds/nodes_main.txt > /tmp/seeds

# try to connect to all of them
for p in $(cat /tmp/seeds) ; do bitcoin-cli addnode $p onetry ; done

# see who is online (include our own addr)
( bitcoin-cli getpeerinfo |jq -r 'map(select(.network == "i2p")) |.[] |.addr' ; bitcoin-cli getnetworkinfo |jq -r '.localaddresses |map(select(.address |test("\\.i2p$"; "i"))) |.[] |.address + ":0"') |sort > /tmp/online

# compare
diff -u0 /tmp/seeds /tmp/online

result:

--- /tmp/seeds	2021-07-30 14:32:26.250310000 +0200
+++ /tmp/online	2021-07-30 14:30:56.333247000 +0200
@@ -5,2 +4,0 @@
-c4gfnttsuwqomiygupdqqqyy5y5emnk5c73hrfvatri67prd7vyq.b32.i2p:0
-dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p:0
@@ -13,0 +12 @@
+sedndhv5vpcgdmykyi5st4yqhdxl3hpdtglta4do435wupahhx6q.b32.i2p:0

• I connect successfully to c4gf... but get disconnected soon after. Maybe that node is overloaded.

• dhtq... gives me Unexpected reply to "NAMING LOOKUP NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p": "NAMING REPLY RESULT=KEY_NOT_FOUND NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p"

• sedn... is an online node, not present in the seeds

[jonatack]

* I connect successfully to `c4gf...` but get disconnected soon after. Maybe that node is overloaded.

Agree, that node can be selective but has been stable since February.

* `dhtq...` gives me `Unexpected reply to "NAMING LOOKUP NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p": "NAMING REPLY RESULT=KEY_NOT_FOUND NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p"`

It was stable until very recently. Sent a message and am waiting to hear from its operator.

* `sedn...` is an online node, not present in the seeds

It was offline for a while. Sent a message and its operator brought it back up and says will maintain its stability. I'll add it in the next push.

[tryphe]

ACK d2dffd5

It's funny how close this is to my list of I2P peers.

Here's a few more I've seen in the past few days that you can add at your discretion:

raoxmlv76s4f4uu275uzaorlr6f2m3yojbspwiciitz6mnl5qnda.b32.i2p:0
igaqpxjupsix5vpxt2bk5dql3md55hvk2n65jzpkwbw6juogyskq.b32.i2p:0

(edit: removed one peer that was making outbound connections but does not accept inbound)

[dunxen]

ACK d2dffd5

I don't have any additional addresses I've seen that haven't already been mentioned here.

I connect successfully to c4gf... but get disconnected soon after. Maybe that node is overloaded.

I am currently connected to c4gfnttsuwqomiygupdqqqyy5y5emnk5c73hrfvatri67prd7vyq.b32.i2p:0 and it has been stable for me for a while already.

[jonatack]

Here's a few more I've seen in the past few days that you can add at your discretion:

raoxmlv76s4f4uu275uzaorlr6f2m3yojbspwiciitz6mnl5qnda.b32.i2p:0
igaqpxjupsix5vpxt2bk5dql3md55hvk2n65jzpkwbw6juogyskq.b32.i2p:0

Yes, these have been stable over the day today. I'm waiting on a couple of people to finish updating their I2P nodes before pushing an update.

[willcl-ark]

ACK d2dffd5

I am connected to about 8 of these, with the hardcoded ones pretty much being the most stable 👍🏼

[laanwj]

ACK d2dffd5

[fanquake]

Backported in #22534.

[jonatack]

dhtq... gives me Unexpected reply to "NAMING LOOKUP NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p": "NAMING REPLY RESULT=KEY_NOT_FOUND NAME=dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p"

It was stable until very recently. Sent a message and am waiting to hear from its operator.

Heard back and dhtq2p76tyhi442aidb3vd2bv7yxxjuddpb2jydnnrl2ons5bhha.b32.i2p is back online... i2pd had stopped working (ubuntu 20.04, i2pd 2.38.0).