NetworkManager Bridges in Fedora

[Dan Williams]

On Sat, 2014-01-18 at 17:35 +0100, Mateusz Marzantowicz wrote:
> On 16.01.2014 21:38, Dan Williams wrote:
> > On Thu, 2014-01-16 at 14:53 -0500, Steve Dickson wrote:
> >>
> >> On 16/01/14 14:39, Steve Dickson wrote:
> >>>
> >>>
> >>> On 16/01/14 14:09, Dan Williams wrote:
> >>>> Also, if wouldn't mind passing along the systemd journal output for
> >>>> NetworkManager, that might help us figure out what's going on:
> >>>>
> >>>> journalctl -b _SYSTEMD_UNIT=NetworkManager.service
> >>> The log is at:
> >>>   http://steved.fedorapeople.org/tmp/nm.log 
> >> I bet ya the hang has something to do with these messages:
> >>
> >>    <info> (bridge0): IPv4 config waiting until carrier is on
> >>    <info> (bridge0): IPv6 config waiting until carrier is on
> >>    <info> Activation (bridge0) Stage 3 of 5 (IP Configure Start) complete.
> >>    
> >> What carrier is it waiting on? em1 is already up and running... 
> > 
> > So what's happening here is that you two
> > configurations/connections/profiles that apply to em1: "ifcfg-em1", and
> > "ifcfg-bridge0_slave_1".  And "ifcfg-em1" is getting chosen, but it's
> > not a bridge slave configuration, it's just a normal DHCP configuration.
> > 
> > Since "ifcfg-em1" is not a bridge slave configuration, it never gets
> > added to the bridge master, and the bridge master sits around waiting
> > for slaves because it has no carrier which is required for DHCP.
> > 
> > Persistent fix #1:
> > edit ifcfg-em1 and change ONBOOT=yes to ONBOOT=no
> > nmcli con reload
> > then do "Runtime fix" below
> > 
> > Persistent fix #2:
> > rm /etc/sysconfig/network-scripts/ifcfg-em1
> > nmcli con reload
> > then do "Runtime fix" below
> > 
> > (or use nm-connection-editor to delete 'em1' or uncheck "Connect
> > automatically" from the General tab.)
> > 
> > Runtime fix (not persistent):
> > nmcli dev disconnect em1
> > nmcli con up "bridge0 slave 1"
> > 
> > 
> > ------
> > (In old "network" service speak, the runtime operation would be:
> > 
> > ifdown em1
> > ifup bridge0_slave_1
> > 
> > and we still expect these commands to work even when NetworkManager is
> > managing the interface.)
> > ------
> > 
> > Dan
> > 
> 
> I'm doing this differently and now I don't know which method is
> recommended by RH/Fedora gurus. I don't use
> /etc/sysconfig/network-scripts at all but placed all network related
> configuration in /etc/NetworkManager/system-connections/ directory. Now
> I'm not sure if I should convert back to using /etc/sysconfig or what?
> Not to mention that GUI tool is c... and I had to use text editor to
> configure network bridging.

Both ifcfg files (/etc/sysconfig/network-scripts) or keyfiles
(/etc/NetworkManager/system-connections) are supported, and the GUI
tools and nmcli work fine with both.  If they don't, that's a bug and
we'll fix it.

Dan