Since #9319 proposed by Gregory Maxwell and released in v0.14, peers manually added through the -addnode config option or using the addnode RPC have their own separate limit of 8 connections that does not compete with other inbound or outbound connection usage and is not subject to the limitation imposed by the -maxconnections option.
This PR updates the -addnode and -maxconnections config options and the addnode RPC help docs with this information.
-addnode config option help
0$ bitcoind -h | grep -A5 addnode=
1 -addnode=<ip>
2 Add a node to connect to and attempt to keep the connection open (see
3 the addnode RPC help for more info). This option can be specified
4 multiple times to add multiple nodes; connections are limited to
5 8 at a time and are counted separately from the -maxconnections
6 limit.
7
8$ bitcoind -h | grep -A3 maxconnections=
9 -maxconnections=<n>
10 Maintain at most <n> connections to peers (default: 125). This limit
11 does not apply to connections manually added via -addnode or the
12 addnode RPC, which have a separate limit of 8.
addnode rpc help
0$ bitcoin-cli help addnode
1addnode "node" "command"
2
3Attempts to add or remove a node from the addnode list.
4Or try a connection to a node once.
5Nodes added using addnode (or -connect) are protected from DoS disconnection and are not required to be
6full nodes/support SegWit as other outbound peers are (though such peers will not be synced from).
7Addnode connections are limited to 8 at a time and are counted separately from the -maxconnections limit.
