Wake On LAN

Wake on LAN is a very useful if you only need to run a computer for a limited time and then shut off.

For instance on a remote NAS you could wake the computer only when you want to sync data from the remote machine.

Fujitsu Siemens Futro A2xx series does support WoL.

You first need to check if the network card supports it.

ifconfig re0 hwfeatures
    hwfeatures=8037<CSUM_IPv4,CSUM_TCPv4,CSUM_UDPv4,VLAN_MTU,VLAN_HWTAGGING,WOL> hardmtu 7422

Next you need to enable it. See ifconfig. Note that you need to re-enable wol on each reboot.

ifconfig re0 wol

You can enable by setting it in hostname.if.

# cat hostname.re0   
inet NONE wol 

If it is not support it might be possible to enable in BIOS.

Next you need the MAC address of the ethernet port of the device.

ping <ip>
arp -a
rock.lounge.se    00:90:dc:a2:4e:71    em0 15m28s

Halt the computer. For some reason the A250 reboot on after first wake on LAN boot when halted. On second halt -p the machine is powered down completely.

halt -p

Then start it by wol

arp -W 00:90:dc:a2:4e:71

This works and should be a very power efficient setup!

But for some strange reason Futro A250 must be halted twice to actually halt after wake on lan wakeup.


Disable KARL on OpenBSD on very restricted machines

chmod 000 /usr/libexec/reorder_kernel

Disable ASLR on OpenBSD on very restricted machines

rcctl disable library_aslr