FWIW, it is my understanding that in DHCP terminology, “renew” (dhcpcd -N or --renew) means to take the existing lease and extend it (i.e. “refresh” it or “renew” it) so that it lasts a longer time, via a unicast DHCP request to the current leasing server. Meanwhile “rebind” (dhcpcd -n or --rebind) means to get a new lease entirely (which may or may not result in the same IP assignment, etc.), via a broadcast DHCP request to any available leasing server.
So I expect dhcpcd -N to perform the same action that dhcpcd itself should take when it’s time to renew a soon-to-be-expiring lease. Maybe that expectation is wrong.
I do recall from my Jan 8 investigations that dhcpcd -N didn’t generate DHCP requests (as seen by tcpdump) while dhcpcd -n would. I don’t know why.
I have Raspberry PI 3B+ running IPfire core 185. Red interface is onboard WiFi and it is connected to Ipfire running at “amd64”, that gateway has PCI WiFi card that works as access point and it works well…
I updated main gateway from core 184 to 185 and that update requires reboot. During gateway reboot, WiFi AP goes down for a minute.
IPfire (core 185) running at RPI was unable to reconnect to gateway when it was back in action. dhcpcd client exited and was not started again There is no button to “disconnect”/“connect” or “reconnect” on red interface (IPcop had such controls at WebUI).
I connect to RPI over ssh and I fixed the connectivity issue with sequence /etc/init.d/networking/red stop and /etc/init.d/networking/red start
This is log (“RED” messages from /var/log/messages). Main gateway was rebooted at about 11:02, it is visible in the log file that issue with WiFi was detected and red0 was removed. At 11:06:10, dhcpcd exited and was not started again! I started it manually at 11:24:29 (/etc/init.d/networking/red start):
11:03:47 dhcpcd[2060] : red0: removing interface
11:03:47 dhcpcd[2060] : script_runreason: No such process
11:03:47 dhcpcd[2060] : red0: deleting default route via 192.168.232.1
11:03:51 dhcpcd[2060] : script_runreason: No such process
11:03:51 dhcpcd[2060] : main: control_stop: No such file or directory
11:03:51 dhcpcd[2060] : dhcpcd exited
11:05:09 dhcpcd[10398] : dhcpcd-10.0.6 starting
11:05:09 dhcpcd[10401] : DUID 00:01:00:01:2c:3f:0c:eb:00:e0:4c:36:00:92
11:05:09 dhcpcd[10401] : red0: connected to Access Point: FireAP
11:05:10 dhcpcd[10401] : red0: IAID eb:57:bd:af
11:05:10 dhcpcd[10401] : red0: rebinding lease of 192.168.232.111
11:05:15 dhcpcd[10401] : red0: DHCP lease expired
11:05:19 dhcpcd[10401] : red0: soliciting a DHCP lease
11:06:10 dhcpcd[10401] : timed out
11:06:10 dhcpcd[10401] : main: control_stop: No such file or directory
11:06:10 dhcpcd[10401] : dhcpcd exited
11:24:29 dhcpcd[13639] : dhcpcd-10.0.6 starting
There is no button to “disconnect”/“connect” or “reconnect” on red interface (IPcop had such controls at WebUI).