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TCP & UDP Ports allocated

1. Main Command​

sudo ss -tuln    # OR: sudo netstat -tuln   (if installed)
  • Lists all open TCP (-t) & UDP (-u) Listening sockets (-l, "servers only") with numeric display.
  • Shows both docker-forwarded AND non-docker services!

You will see lines like:

Netid State   Recv-Q Send-Q Local Address:Port      Peer Address:Port
tcp   LISTEN  ...     127.0.0.1:5432               ...
tcp   LISTEN         *:80                          ...
udp          ...     [::]:68                       ...
...

If you need process names/pids add option (ss preferred now):

sudo ss -tplun        # Adds PID/program column!
# Or for full detail use 'p' (=processes):       ^^^^

2️⃣ Combine With Your Docker Allocation Table​

The output of docker ps --format "{{json .}}" | jq '.' gives a structured version just for running container mappings—but these are already included as “bound” by dockerd proxying them onto real interfaces via NAT/br-net bridges/etc.

So everything shown in either tool is considered an active port binding.

Example Aggregate Steps:​

Get ONLY used host-side TCP ports ("what's actually being held" no matter who holds it):​
sudo lsof -iTCP -sTCP:LISTEN -P +c15 |
awk '{print $9}' |
grep ':' |
sort | uniq                    # shows e.g., localhost:*hostport*

For UDP listeners instead:

sudo lsof -iUDP    # or customize further per needs …

Or more simply get (protocol/interface/address/IP/PORT) mapping at once using SS/netstat/lsof combinations seen here.