[PLUG] more Quantum Fiber: VLANs

[Russell Senior]

If you have a terminal on the OpnSense box, a tcpdump command
something like this:

  tcpdump -n -i eth0 'tcp[tcpflags] & tcp-syn != 0 and tcp[tcpflags] &
tcp-ack == 0 and dst $publicipaddr and tcp port 443'

Where $publicipaddr is the IP address of the WAN interface. This will
show all the SYN packets arriving with tcp port 443.

On Sun, Oct 6, 2024 at 9:43 PM Russell Senior <russell at pdxlinux.org> wrote:
>
>
>
> On 10/6/24 15:13, Courtney Rosenthal wrote:
> > I posted last week about not getting IPv6 on my Quantum Fiber
> > connection. I haven't resolved that -- but I've got an even greater
> > concern: I'm not receiving any inbound TCP connection requests.
> >
> > (Again, I'm not using the default router. I'm using an OpnSense router
> > built with a Qutom mini-pc.)
> >
> > My outbound TCP is working fine. My router is receiving and responding
> > to ICMP PING messages. But packet capture at the router WAN interface
> > shows incoming TCP connection request are never arriving.
>
> To see if there is any filtering going on, you need to do packet capture
> at the OpnSense box:
>
> https://docs.opnsense.org/manual/diagnostics_interfaces.html#packet-capture
>
> and see if the packets arrive.
>
> If they don't, then something upstream is filtering them. If they arrive
> on the OpnSense WAN interface, then look at the LAN interface and see if
> they are being forwarded appropriately by OpnSense.
>
> I don't have any experience with OpnSense,
>
> --
> Russell Senior
> russell at pdxlinux.org