I've been trying out some failure scenarios with Eth vs. GSM modem (under ModemManager) - e.g. Eth link getting disconnected/reconnected.
eth0 was present in my /etc/network/interfaces: auto eth0 iface eth0 inet dhcp therefore I used the "managed=true" setting in NetworkManager.conf, with the ifupdown plugin. Board is booted with the eth cable connected. I'm not using systemd. => root@wg:~# nmcli conn NAME UUID TYPE DEVICE eth0 100f5a79-f573-44ca-b746-04727dab4a7d 802-3-ethernet eth0 Ifupdown (eth0) 681b428f-beaf-8932-dce4-687ed5bae28e 802-3-ethernet -- O2 42bf3c07-9dd7-45f6-ba08-37dfc8a7a537 gsm -- I bring up the MM GSM connection. Nameservers for both appear in resolv.conf, and 'route' shows both eth0 and ppp0. I can [busybox] ping a site by name on ppp0 (using the -I option). I then unplug the eth cable, and the ping then fails [eventually!] with "bad address". (It works if I specify IP addr instead). It works (by name) when I reconnect the the cable. root@wg:~# nmcli ttyMux1: connected to O2 gsm (linmux), hw, iface ppp ip4 default inet4 10.65.57.212/32 eth0: unavailable ethernet (fec), 00:0C:C6:7F:E5:51, hw, mtu 1500 lo: unmanaged loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536 DNS configuration: servers: 82.132.254.2 82.132.254.3 interface: ppp0 servers: 192.168.10.254 interface: eth0 root@wg:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.10.254 0.0.0.0 UG 0 0 0 eth0 0.0.0.0 10.65.57.212 0.0.0.0 UG 700 0 0 ppp0 10.65.57.212 0.0.0.0 255.255.255.255 UH 700 0 0 ppp0 192.168.10.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 root@wg:~# cat /etc/resolv.conf # Generated by NetworkManager nameserver 82.132.254.2 nameserver 82.132.254.3 nameserver 192.168.10.254 On disconnect of the cable, NM logs: May 11 15:47:45 wg2xx-tx6s user.info kernel: fec 2188000.ethernet eth0: Link is Down May 11 15:47:49 wg2xx-tx6s daemon.info NetworkManager[850]: <info> [1494514069.2116] device (eth0): state change: activated -> unavailable (reason 'carrier-changed') [100 20 40] May 11 15:47:49 wg2xx-tx6s daemon.info NetworkManager[850]: <info> [1494514069.2324] policy: set 'O2' (ppp0) as default for IPv4 routing and DNS May 11 15:47:49 wg2xx-tx6s daemon.notice dbus[824]: [system] Activating service name='org.freedesktop.nm_dispatcher' (using servicehelper) May 11 15:47:49 wg2xx-tx6s daemon.notice dbus[824]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' May 11 15:47:49 wg2xx-tx6s daemon.info nm-dispatcher: req:1 'down' [eth0]: new request (1 scripts) May 11 15:47:49 wg2xx-tx6s daemon.info nm-dispatcher: req:1 'down' [eth0]: start running ordered scripts... In contrast however, if I comment eth0 out of /etc/network/interfaces and reboot (with eth cable reconnected) and repeat, then the ppp0 ping works fine after disconnecting the eth cable. root@wg:~# nmcli ttyMux1: connected to O2 gsm (linmux), hw, iface ppp ip4 default inet4 10.67.91.236/32 eth0: unavailable ethernet (fec), 00:0C:C6:7F:E5:51, hw, mtu 1500 lo: unmanaged loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536 DNS configuration: servers: 82.132.254.2 82.132.254.3 interface: ppp0 root@wg:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.67.91.236 0.0.0.0 UG 700 0 0 ppp0 10.67.91.236 0.0.0.0 255.255.255.255 UH 700 0 0 ppp0 root@wg:~# cat /etc/resolv.conf # Generated by NetworkManager nameserver 82.132.254.2 nameserver 82.132.254.3 It seems the dns lookup is being tried on eth0 instead of ppp0 - as if the 'managed=true' isn't altering all the behaviour that it should be? (e.g. in the failing case, eth0 is still showing in resolv.conf & in the routing table...?). I have no pre/post up/down scripts in /etc/network/ eth0 is in /etc/network/interfaces for not conscious reason - just the way by image is building at present. I could chop it out if necessary, but as I'm sticking my on NetworkManager.conf into the rootfs anyway, that would be an easier way to flick the behaviour, if I can get it to work equivalently. _______________________________________________ networkmanager-list mailing list networkmanager-list@gnome.org https://mail.gnome.org/mailman/listinfo/networkmanager-list