Why do nodes have a second connection to each other?

Under peer analysis in gLiveView, why do my nodes have two connections to each other?

The correct ports for each of the nodes are 64100, 64101 & 64102. The second connection is using a seemingly random port.

Here’s a couple screenshots to illustrate:

Screenshot

Kind regards
Adam

I noticed this behavior also… I didn’t tried to restart the node… did u?

Yes, it persists after a restart.

Strange too because the random ports should be blocked by firewall.

I belive there are the outgoing ports not incoming ports

I do not use gLiveView, but yes as @Alexd1985 wrote each BP will have one outgoing connection to relay, that what you put in topology file of BP and one incoming connection from relay, because again you put in topology file of relay BP there. Outgoing connections are from ephemeral ports or high random port to port what you configure.

Usually you allow all outgoing traffic, that why it is not blocked by FW, but technically you can block outgoing traffic too.

Here short manual:

http://www.tcpipguide.com/free/t_TCPIPClientEphemeralPortsandClientServerApplicatio-3.htm

Additionally your FW has following rule:

iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

This means that we do allow connections what were established, basically if we opened connection from BP to relay port 64102, then we will accept replies from any port from relay. That why your BP allows connection at port 40431 for example.