Keep record of known peers

[germsvel]

When dealing with the Encrypted Handshake, our node can establish a connection with a known peer; that is, a node that we've connected to before. In order to be able to do that, we need to keep a session token.

From the Encrypted Handshake link above,

There are two kinds of connections which can be established. A node can connect to a known peer, or a node can connect to a new peer. A known peer is one which has previously been connected to and from which a corresponding session token is available for authenticating the requested connection.

[hayesgm]

I thought like I read somewhere that the other P2P clients (Geth/Parity) do not use this feature. Do we know the status of this session token usage in other implementations?

[germsvel]

I do not know the status of that in other implementations. I just assumed they were using those tokens but haven't checked.

[InoMurko]

I think this is relevant to #639