On Tue, Nov 24, 2020 at 03:06:59PM -0800, pe...@easthope.ca wrote: > > "allow-hotplug" tells udev to raise a network interface after it's > > attached to the kernel. This result of ifup is expected. > > OK, thanks. Same as "auto <interface>"?
No. "auto" means (taken directly from interfaces(5)): Lines beginning with the word "auto" are used to identify the physical interfaces to be brought up when ifup is run with the -a option. (This option is also used by the system boot scripts, so interfaces marked "auto" are brought up at boot time). The main difference between "auto" and "allow-hotplug" is, well, hotplug processing. And judging from that "predictable" interface name, you're using an USB dongle, so hotplug is important here. > This is the only oddity evident after ifup wlxa0f3c10a28f7. > > DHCPDISCOVER on wlxa0f3c10a28f7 to 255.255.255.255 port 67 interval 3 > send_packet: No buffer space available > dhclient.c:2445: Failed to send 300 byte long packet over wlxa0f3c10a28f7 > interface. > > Nevertheless, after a few more lines from DHCP the link works. > Any ideas about buffer space? The kernel has no free RAM to queue a packet or that Tp-Link device you're is using low-quality kernel module. Happens with Tp-Link, but there's a bright side - it could've been Broadcom. Try increasing a value of vm.min_free_kbytes, it may help. Reco