On Wed, Sep 27, 2023 at 12:31 PM Mark Rogers <m...@more-solutions.co.uk> wrote:
> On Wed, 27 Sept 2023 at 10:18, Mantas Mikulėnas <graw...@gmail.com> wrote: > >> So now I'm curious: if the first command you run is to bring the >> interface *down*, then what exactly brought it up? >> > > Good question. The reason for down/up was that this was working as a way > to reset the connection after boot, so I just transferred that to the > ExecStartPre. > > Looking at the "journalctl -u dhcpcd" output, this is what I see from my > last boot: > Feb 14 10:12:05 pi systemd[1]: Starting dhcpcd on all interfaces... > Feb 14 10:12:05 pi ip[372]: 2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc > noop state DOWN group default qlen 1000 > Feb 14 10:12:05 pi ip[372]: link/ether b8:27:eb:0d:ee:bb brd > ff:ff:ff:ff:ff:ff > Feb 14 10:12:05 pi ip[383]: 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> > mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000 > Feb 14 10:12:05 pi ip[383]: link/ether b8:27:eb:0d:ee:bb brd > ff:ff:ff:ff:ff:ff > Feb 14 10:12:06 pi dhcpcd[385]: wlan0: starting wpa_supplicant > Feb 14 10:12:36 pi dhcpcd[385]: timed out > Feb 14 10:12:36 pi systemd[1]: Started dhcpcd on all interfaces. > Feb 14 10:12:37 pi systemd[1]: Stopping dhcpcd on all interfaces... > Feb 14 10:12:37 pi dhcpcd[519]: sending signal TERM to pid 466 > Feb 14 10:12:37 pi dhcpcd[519]: waiting for pid 466 to exit > Feb 14 10:12:38 pi systemd[1]: dhcpcd.service: Succeeded. > Feb 14 10:12:38 pi systemd[1]: Stopped dhcpcd on all interfaces. > Feb 14 10:12:38 pi systemd[1]: Starting dhcpcd on all interfaces... > Feb 14 10:12:38 pi ip[524]: 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> > mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000 > Feb 14 10:12:38 pi ip[524]: link/ether b8:27:eb:0d:ee:bb brd > ff:ff:ff:ff:ff:ff > Feb 14 10:12:38 pi ip[529]: 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu > 1500 qdisc pfifo_fast state UP group default qlen 1000 > Feb 14 10:12:38 pi ip[529]: link/ether b8:27:eb:0d:ee:bb brd > ff:ff:ff:ff:ff:ff > Feb 14 10:12:38 pi dhcpcd[530]: wlan0: starting wpa_supplicant > Feb 14 10:12:49 pi dhcpcd[530]: Too few arguments. > Feb 14 10:12:49 pi dhcpcd[530]: Too few arguments. > Feb 14 10:12:49 pi systemd[1]: Started dhcpcd on all interfaces. > > (I deleted the "ip addr" output from the interfaces other than eth0 for > brevity.) > > The interesting thing is surely that dhcpcd is being started twice. > Assuming that was always happening then that suggests dhcpcd was bringing > the network up early (and failing but leaving it in a "stuck" state) and > then again later (where it was unable to recover from the first failure, > but now can)? > That's possible... but again, I don't see how it would get into this "stuck" state in any other way but driver and/or hardware issues, as the kernel driver is where the power-up sequence is done... dhcpcd (like 'ip link set eth0 up') pretty much just tells the OS to power the NIC on, then waits. (My previous laptop had a Realtek Ethernet NIC that often wouldn't recognize Ethernet link after suspend/resume until I removed it from the PCI bus... took several kernel releases until they fixed that.) -- Mantas Mikulėnas
