On Fri, Mar 06, 2026 at 02:23:32PM +0100, Frans Schneider wrote:
>
> Op 06-03-2026 om 2:12 p.m. schreef Dave Voutila:
> > Frans Schneider <[email protected]> writes:
> >
> > > Somehow I can't get networking to work under virtualization. Probably
> > > a simple mistake, but I can't find it.
> > >
> > > On an old Dell laptop (> 15 years old) I performed a completely fresh
> > > 7.8 install. Everything is default.
> > > I configure a bridge:
> > >
> > > add em0
> > > up
> > >
> > > and em0:
> > >
> > > inet autoconf
> > > up
> > >
> > > Output of ifconfig:
> > >
> > > em0:
> > > flags=808b43<UP,BROADCAST,RUNNING,PROMISC,ALLMULTI,SIMPLEX,MULTICAST,AUTOCONF4>
> > > mtu 1500
> > >      lladdr 5c:26:0a:13:52:0a
> > >      index 1 priority 0 llprio 3
> > >      groups: egress
> > >      media: Ethernet autoselect (1000baseT
> > > full-duplex,master,rxpause,txpause)
> > >      status: active
> > >      inet 192.168.178.118 netmask 0xffffff00 broadcast 192.168.178.255
> > >
> > > bridge0: flags=41<UP,RUNNING> mtu 1500
> > >      description: switch1-uplink
> > >      index 5 llprio 3
> > >      groups: bridge
> > >      priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp
> > >      designated: id 00:00:00:00:00:00 priority 0
> > >      tap0 flags=3<LEARNING,DISCOVER>
> > >          port 7 ifpriority 0 ifcost 0
> > >      em0 flags=3<LEARNING,DISCOVER>
> > >          port 1 ifpriority 0 ifcost 0
> > >      Addresses (max cache: 100, timeout: 240):
> > >
> > > vm.conf contains:
> > >
> > > switch "uplink" {
> > >      interface bridge0
> > > }
> > >
> > > # OpenBSD snapshot install test
> > > vm "openbsd.vm" {
> > >      enable
> > >      memory 1G
> > >      disk "/var/vmm/images/obsd.qcow2"
> > >      cdrom "/var/vmm/iso/install78.iso"
> > >      interface {switch "uplink"}
> > > }
> > >
> > > After starting the vm, ifconfig on the vm shows:
> > >
> > > vio0:
> > > flags=808b43<UP,BROADCAST,RUNNING,PROMISC,ALLMULTI,SIMPLEX,MULTICAST,AUTOCONF4>
> > > mtu 1500
> > >      lladdr fe:e1:bb:d1:0c:f8
> > >      llprio 3
> > >      groups: dhcp
> > >      media: Ethernet autoselect
> > >      status: active
> > >
> > > So far everything looks fine, but no matter what I do, I can't get any
> > > network traffic to the network.
> > >
> > Which network? The internet?
> Neither local LAN or internet. Total silence.
> >
> > > I've tried both Alpine virtual and standard, and OpenBSD in the meantime.
> > >
> > > On the host I've tried bridging and veb as described in the FAQ, but
> > > without success.
> > >
> > > What could be wrong?
> > Did you follow the examples for /etc/pf.conf and configured NAT?
> Since I use bridging (or veb), the firewall is or should be of no concern
> (?) I made no changes to pf.conf from the default install.
>
> I did use both the OpenBSD FAQ (Networking -> Option 4 VMs on the real
> network and the OpenBSD Handbook Virtualization -> Setting Up Bridged
> Networking.
>
>
>

does your upstream dhcp server (the one that gave em0 its address) give out
more than one address per port/connection? It's going to see what amounts to
two different dhcp requests with different mac addresses on em0 in this
config, I think.

when the vm is looking for an address, what does tcpdump on tap0 and/or
bridge0 / em0 on the host show? can you see dhcp requests and responses flowing?

Reply via email to