From: Bradley Hook <bhook@kansasdeaf.gov>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter@vger.kernel.org
Subject: Re: Packets not traversing postrouting chain
Date: Mon, 31 Mar 2025 12:00:20 -0500 [thread overview]
Message-ID: <CAPrh4R6NrbEXPg36Ogu-ftaoLQf84FDQAu-TjJdnY5HERQCvhg@mail.gmail.com> (raw)
In-Reply-To: <Z-rIIhraCyG8KELs@calendula>
I was in the process of investigating conntrack when your message came
in. This all happened while the machine was active and the interface
for the faulty ISP was still "up". There was a cached SNAT entry in
conntrack that was bypassing the application of the updated rules. I
flushed everything with conntrack -D -p udp (the main issue was SIP
traffic) and everything cleared up immediately.
Respectfully,
~Bradley Hook, J.D.
Network Administrator
Google Certified Project Manager
Kansas State Schools for the Deaf and the Blind
bhook@kansasdeaf.gov
Mobile: 913-275-9982
On Mon, Mar 31, 2025 at 11:51 AM Pablo Neira Ayuso <pablo@netfilter.org> wrote:
>
> On Mon, Mar 31, 2025 at 11:19:31AM -0500, Bradley Hook wrote:
> [...]
> > The issue we are seeing is that packets from 192.168.122.252 to
> > 8.8.8.8 are not traversing the postrouting chain at all. We can see
> > the packets leaving the interface without NAT applied. We can see the
> > packets hitting the forward chain with the trace. Other traffic from
> > other subnets are being masqueraded just fine. We just aren't seeing
> > the packets from 192.168.122.x/24 hit any postrouting rules at all.
>
> Can you check if connection tracking is tagging these packets as
> invalid?
--
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prev parent reply other threads:[~2025-03-31 17:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-31 16:19 Packets not traversing postrouting chain Bradley Hook
2025-03-31 16:51 ` Pablo Neira Ayuso
2025-03-31 17:00 ` Bradley Hook [this message]
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