From: listy <listy@localities.work>
Cc: netfilter@vger.kernel.org
Subject: Re: dummy net iface?
Date: Sat, 21 Feb 2026 09:48:38 +0100 [thread overview]
Message-ID: <61080b94-afdd-48c2-bb7c-74aacf3d9352@localities.work> (raw)
In-Reply-To: <CAPJdpdBYt-VTdjeZ-X8BeLNTuxSmKssacgZEin9jFjypEqkEUA@mail.gmail.com>
Yes I did/do have net.ipv4.ip_forward = 1
Then I must be doing something wrong or not doing something.
I run a container which listens on a dummy iface, well,
'pasta' does it on behalf of 'podman'
-> $ nmap 10.9.4.7 -p 5350
...
5350/tcp open nat-pmp-status
-> $ nmap 10.9.4.7 -p 5350 -sU
...
5350/udp open|filtered nat-pmp-status
what listens is a dns recursor, then 'firewalld' looks like so:
-> $ firewall-cmd --list-all --zone=mine-fwd-dummy
mine-fwd-dummy (active)
target: default
icmp-block-inversion: no
interfaces: forwarder-dummy
sources:
services:
ports:
protocols:
forward: yes
masquerade: no
forward-ports:
port=53:proto=tcp:toport=5350:toaddr=10.9.4.7
port=53:proto=udp:toport=5350:toaddr=10.9.4.7
source-ports:
icmp-blocks:
which results in:
-> $ nft list table inet firewalld
...
chain nat_PRE_mine-fwd-dummy_allow {
meta nfproto ipv4 tcp dport 53 dnat ip to
10.9.4.7:5350
meta nfproto ipv4 udp dport 53 dnat ip to
10.9.4.7:5350
}
...
forwarder-dummy is: 10.9.4.7
yet
-> $ nmap 10.9.4.7 -p 53
...
53/tcp closed domain
same for 'udp'
I'm on Centos 9 with 6.12.74-1.el9.x86_64
If I'm missing something - what that might be..
thanks, L
prev parent reply other threads:[~2026-02-21 8:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-20 11:08 dummy net iface? listy
2026-02-20 11:39 ` Paul Robert Marino
2026-02-20 11:52 ` Paul Robert Marino
2026-02-21 8:48 ` listy [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=61080b94-afdd-48c2-bb7c-74aacf3d9352@localities.work \
--to=listy@localities.work \
--cc=netfilter@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox