On Nov 20, 2020, at 14:31, Michael B Allen <ioplex at gmail.com> wrote: > > Well I've managed to resolve the issue but I'm not entirely satisfied > with the solution. Apparently firewalld and iptables are at least > partially mutually exclusive such that changes to iptable have no > effect. That’s not strictly true, at least with firewalld and iptables. You added the iptables rule with -A (append). The firewalld rules add jump rules to the input table and your rule simply was never reached, because traffic was blocked in one of the earlier rules. This would be the case in any complex iptables config too. Had you really wanted to test something with iptables, use -I (insert) which puts it at the front of the rules. Obviously, the best thing to do is to use firewalld tools with firewalld. -- Jonathan Billings <billings at negate.org>