Re: Bridging Network Connections with libvirt are unreliable

[Tim Woodall <debianuser@woodall.me.uk>]

On Wed, 28 Aug 2024, Rainer Dorsch wrote:

> In the systemd log, the first entry indicating network problems is that the DNS
> server switches to another interface. But it could easily be a consequence and
> not the cause of the issue:
>
> Aug 28 06:57:54 h370 dhclient[1195]: DHCPREQUEST for 192.168.4.203 on eno1.4
> to 192.168.4.1 port 67
> Aug 28 06:57:54 h370 dhclient[1195]: DHCPACK of 192.168.4.203 from 192.168.4.1
> Aug 28 06:57:54 h370 dnsmasq[2386]: reading /etc/resolv.conf
> Aug 28 06:57:54 h370 dnsmasq[2386]: using nameserver 192.168.4.1#53
> Aug 28 06:57:54 h370 dhclient[1195]: bound to 192.168.4.203 -- renewal in
> 18265 seconds.

To me that looks like it's the DHCP request(renewal?) that is more
likely breaking things. The DHCP server is presumably rewriting
resolv.conf.

I have the following setting to stop dhcp changing resolv.conf:

$ cat /etc/dhcp/dhclient-enter-hooks.d/nodnsupdate
make_resolv_conf() {
        :
}

Don't know if that will fix your problem but it should hopefully stop
those dnsmasq lines appearing in the log.

Does the problem definitely happen when the dhcp update happens or are
these just the nearest logs?

Tim.