test: ensure p2p_private_broadcast.py has connections to all nets #34410

1. 
   vasild commented at 12:05 pm on January 26, 2026: contributor

   If the following two events happen:

   • (likely) the automatic 10 initial connections are not made to all networks
   • (unlikely) the network-specific logic kicks in almost immediately. It is using exponential distribution with a mean of 5 minutes (rng.rand_exp_duration(EXTRA_NETWORK_PEER_INTERVAL)).

   So if both happen, then the 11th connection may not be the expected private broadcast, but a network-specific connection.

   Fix this by manually opening a connection to each network upfront. Before filling addrman, because once addrman has addresses the manual addnode connections will race with the automatic ones.

   Fixes: #34387

2. test: ensure p2p_private_broadcast.py has connections to all nets

   If the following two events happen:
   
   * (likely) the automatic 10 initial connections are not made to all
     networks
   * (unlikely) the network-specific logic kicks in almost immediately.
     It is using exponential distribution with a mean of 5 minutes
     (`rng.rand_exp_duration(EXTRA_NETWORK_PEER_INTERVAL)`).
   
   So if both happen, then the 11th connection may not be the expected
   private broadcast, but a network-specific connection.
   
   Fix this by manually opening a connection to each network upfront.
   Before filling addrman, because once addrman has addresses the manual
   `addnode` connections will race with the automatic ones.
   
   Fixes: https://github.com/bitcoin/bitcoin/issues/34387

   590a7b2595
3. test: use port 0 for I2P addresses in p2p_private_broadcast.py

   I2P addresses must use port=0, otherwise `bitcoind` refuses to connect.
   
   The test `p2p_private_broadcast.py` cannot simulate connections to I2P
   peers, so the I2P proxy is set to a dummy `127.0.0.1:1`. Still it is
   good to pick I2P addresses and attempt connections to increase coverage.
   
   However the test uses port=8333 for I2P addresses and thus the
   connection attempts fail for the "wrong" reason:
   
   ```
   Error connecting to ...i2p:8333, connection refused due to arbitrary port 8333
   ```
   
   Using the proper port=0 makes the failures:
   
   ```
   Error connecting to ...i2p:0: Cannot connect to 127.0.0.1:1
   ```
   
   which will make possible simulated I2P connections once we have a test
   I2P proxy.

   01757699f3
4. DrahtBot added the label Tests on Jan 26, 2026
5. 
   DrahtBot commented at 12:05 pm on January 26, 2026: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/34410.

   Reviews

   See the guideline for information on the review process. A summary of reviews will appear here.

6. maflcko added this to the milestone 31.0 on Jan 26, 2026
7. DrahtBot added the label CI failed on Jan 26, 2026
8. 
   fanquake commented at 2:15 pm on January 26, 2026: member

   Looks like this causes the test to timeout in most CIs. I see the same failure locally.

Contributors
vasild DrahtBot fanquake

Labels
Tests CI failed

Milestone
31.0