On 10/13/2014 04:56 PM, Canek Peláez Valdés wrote: > On Mon, Oct 13, 2014 at 6:39 PM, walt <w41...@gmail.com> wrote: >> I just switched my home LAN from wired to all wifi and I'm having trouble >> with NetworkManager at boot time. >> >> I have systemd start NetworkManager at boot because I need the internet >> for ntpdate and to start the nfs server for the LAN. Before I switched >> to all-wireless this method worked perfectly, but no longer. >> >> After bootup I see that NetworkManager started wpa_supplicant in the >> background, but apparently does *not* run dhcpcd. (The wlan0 is up >> but it has no IP address and the routing table is empty.) > > Do you have a system-wide connection for the wireless network? They > live in /etc/NetworkManager/system-connections. Also, what does "nmcli > -p general" says? In my case is: > > centurion ~ # nmcli -p general > ============================================================= > NetworkManager status > ============================================================= > STATE CONNECTIVITY WIFI-HW WIFI WWAN-HW WWAN > ------------------------------------------------------------- > connected full enabled enabled enabled enabled > >> As an alternative to NetworkManager I can have systemd start dhcpcd >> at boot, which almost (but not quite) works well enough. This >> causes a race condition because wlan0 takes several seconds to come >> up properly and by then both ntpdate and nfs-server have already >> run and failed. >> >> So, I asked myself, why not have systemd start dhcpcd at boot in >> addition to NetworkManager? > > NetworkManager starts wpa_supplicant, but it does *NOT* use > wpa_supplicant.conf. If you do > > systemctl status wpa_supplicant.service > > you will see that wpa_supplicant runs with the "-u" flag; that enables > the DBus control interface, and it's through this that NetworkManager > controls wpa_supplicant. If you do not have system-wide connections, > NM will ask wpa_supplicant to *not* enable any connection. NM calls > the shots in this case. > >> The reason that fails is that they both start wpa_supplicant in >> the background and the two instances interfere with each other. >> >> Anyone see a way around this catch22? > > If I'm not mistaken, you need a system-wide NM connection enabled. You > can use nm-connection-editor (included with nm-applet), or nmtui > (ncurses interface since 0.9.10.0). > > Also, and orthogonal to almost all of this; I switched from ntp to > systemd-timesyncd, and it works *great*, specially in my laptop. With > my laptop, changing networks all the time, ntpd never quite worked.
Lots of great information, thanks. What I learned while following up on your hints is that the NM behavior I thought was a bug is merely a feature ;) After boot, but before startx, wlan0 exists but is not properly set up. After X is running I can use the nm-applet to click on the name of my wireless network and *then* NM runs dhcpcd to configure wlan0 and set up the routing table. It works, but I need to do that manually after every boot, not really optimal for my purpose. I tried Neil's suggestion to use systemd-networkd and it works perfectly for this (desktop) machine. (BTW enabling systemd-networkd also pulls in systemd-timesyncd, which works great, just as you said.) Great advice Canek and Neil, and very much appreciated.
