Re: Is traceroute supposed to work in user mode networking (slirp) ?

[Samuel Thibault]

Ottavio Caruso, le dim. 19 juil. 2020 12:07:21 +0100, a ecrit:
> On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> wrote:
> > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit:
> > > I cannot get traceroute to work with standard udp from any of my
> > > guests.
> > >
> > > $ traceroute 8.8.8.8
> > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets
> > >  1  * * *
> >
> > That was because
> >
> > - libslirp was not forwarding the ttl value, thus always set to 64 hops
> > - libslirp was not reporting icmp errors.
> >
> > I had a try at both, and that indeed seems to be fixing the issue:
> > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48
> > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49
> >
> > > Any clues? Is this intended behaviour? Any workarounds that don't
> > > involve tap/tun/bridges?
> >
> > Not without updating libslirp with the abovementioned patches.
> 
> Thanks Samuel. I've added a comment on the portal, but for the benefit
> of qemu-devel:
> 
> Applying this patch on the latest qemu (5.0.90),

Did you also apply
https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 ?

Samuel