Check whether a Bitcoin peer falls under a manual subnet ban
A trusted peer can stop reconnecting because an earlier maintenance action banned a whole subnet. The relevant entry may not spell out the exact host address.
Inspect subnet and expiry together
Read the node's manual ban list. banned_until is a Unix timestamp, while time_remaining is a duration in seconds. Compare the peer's actual connection IP with every listed subnet.
bitcoin-cli listbanned | jq '.[] | {address, banned_until, time_remaining}'
Check the prefix, not just the text
For example, a peer at 192.0.2.42 belongs to 192.0.2.0/24. A plain string comparison against the address would miss this rule. If no active subnet matches, examine firewall rules and peer connection logs separately. An empty manual ban list cannot confirm end-to-end connectivity.