Re: User mode networking with slirp on MacOs, setting host DNS server?

[Biff Eros]

I noticed this:
https://github.com/qemu/libslirp/commit/5ac17660a76e321c37e6dca2e3c04d9d7d2b7ff4
So maybe slirp doesn't do DNS in quite the way I expect on MacOs.

In any case I couldn't figure out how to make changes to slirp and compile them
into a new Qemu, I put a compile error into a file in the slirp
directory and re-ran
the top-level make and it didn't fail.  I was going to just change the
/etc/resolv.conf
string to /usr/local/etc/resolv.conf and put my alternate address in
there but I haven't
figured out how to do that even.

On Tue, Jun 22, 2021 at 6:27 AM Narcis Garcia <debianlists@actiu.net> wrote:
>
> __________
> I'm using this dedicated address because personal addresses aren't
> masked enough at this mail public archive. Public archive administrator
> should fix this against automated addresses collectors.
> El 22/6/21 a les 0:59, Biff Eros ha escrit:
> > Looking at this bug report:
> > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=625689
> >
> > There is this comment:
> >
> > mjt@tls.msk.ru wrote:
> >
> >> No the limitation isn't documented (yet), and it will be difficult
> >> to fix too, or maybe not worth a trouble really.  Two reasons.
> >> First of all, user-mode networking is not suitable for anything
> >> serious, you really want tap networking with bridges, which is
> >> about 100 times faster and actually works (e.g. ICMP).  Second,
> >> the implementation is rather simplistic - for DNS it merely
> >> forwards (like a NAT box) packets from guest to a nameserver
> >> from host /resolv.conf - only one nameserver, because you can't
> >> NAT to TWO destinations at once.  So in order to fix that,
> >> qemu has to become application-level proxy for DNS, instead
> >> of a simple NAT "device".
> >
> > Unfortunately I'm on MacOs, and I don't want to be using resolv.conf.
> > I want it to use a locally running dnsmasq instead.  Can anyone point
> > me to which bit of source I need to change to hard-code this to
> > 127.0.0.1, or is that out of the question?
> >
>
> You should be able to point resolv.conf nameserver to your dnsmasq IP.
>
>