Which Ports Need to Be Opened for libp2p in a Mandatory Firewall?

[Ja7ad]

I noticed that go-libp2p uses different ports to connect to other nodes.

 1330298            root  652u  IPv4 266053404      0t0  TCP 23.109.234.125:21888->142.61.131.16:21888 (ESTABLISHED)
 1330298            root  653u  IPv4 266053839      0t0  TCP 23.109.234.125:21888->111.76.109.19:21888 (ESTABLISHED)
 1330298            root  654u  IPv4 266053347      0t0  TCP 23.109.234.125:21888->122.90.163.168:21888 (ESTABLISHED)
 1330298            root  656u  IPv4 266045717      0t0  TCP 23.109.234.125:44826->33.27.37.129:21888 (ESTABLISHED)
 1330298            root  657u  IPv4 266056787      0t0  TCP 23.109.234.125:21888->62.115.26.183:21888 (ESTABLISHED)

Port in question: 44826

What is the purpose of this port? Additionally, which ports do I need to open on the firewall to ensure proper reachability for go-libp2p?

[p-shahi]

I believe 44826 is an ephemeral outbound port that was dynamically assigned by the OS.
If you enable hole punching you'll be able to ensure proper reachability for your node behind a NAT/firewall