iptables - direction independent filtering

Question

firstly, I'm excited to use this chance to post my first question on this resource and jump away from the readers' crowd.

Using iptables, we need to filter network packets regardless of their direction but based on source and destination addresses only, including protocols and ports, of course, but the main thing is that direction should not make sense.

To avoid messing up the existing ruleset I think of adding a new custom chain and add all those rules into it but the issue is that after being added it stays unreferenced and hence not active. What's the best practice to immediately activate a newly created chain?

Thank you.

Answer 1

jump to it:

iptables -A INPUT  -j my-chain