Re: port forward from guest to host- inquiry

[David Gibson <david@gibson.dropbear.id.au>]

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On Sat, Oct 25, 2025 at 01:02:36AM +0100, baleti wrote:
> does anyone know if passt can port forward from guest to host? I'm trying to
> make a diod server available on the guest?

I'm assuming you're using passt (guest is a VM) not pasta (guest is a
container).

> 
> on host I run a service listening on 9564:
>  ~ $ diod --foreground --listen 0.0.0.0:9564 --export
> /home/user/autocad-ballet --no-auth
> 
> is there a way for passt to make it available on the guest?

Yes, but you don't need an explicit forward for this - passt's default
behaviour is to let the guest access things outside, including the
host.  The complication is that, by default, the guest gets the same
address as the host, so the guest can't access the host using it's
normal address.

However, also by default, we remap the default gateway address to the
host.  That is, if on the guest you connect to the address of the
default gateway, port 9564, that will actually connect to diod on the
host.

The details of this can be adjusted with the --map-host-loopback,
--map-guest-addr and -no-map-gw options.

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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