Create a Cron Job to Run on a Schedule

[T0mmy1977]

I need to run the following command on a schedule for WoL purposes.

arp -s IP MAC

I have the command in the services-start file, but the ARP table gets flushed. I am new to cron jobs. Can you please tell me how to run the command on a schedule? Thanks

 

[toforrao]

Maybe this is working for you?

CRON Job help - Activate CRON job if a device is present

Hi guys, Im wondering if you can steer me in the right direction. I have a cron job in my AX86u in services-start which works fine. It to send a WOL to my NAS at a certain time on a certain day: arp -i br0 -s 192.x.x.x xx:xx:xx:xx:xx:xx cru -a naswol "55 19 * * 6 /usr/sbin/ether-wake -i br0...

www.snbforums.com

 

[ColinTaylor]

Try something like this in your services-start script.

#!/bin/sh

/usr/sbin/cru a WoL "*/10 * * * * arp -s IP MAC"

 

[T0mmy1977]

Try something like this in your services-start script.

#!/bin/sh

/usr/sbin/cru a WoL "*/10 * * * * arp -s IP MAC"

This appears to work. Thanks!

 

[T0mmy1977]

It still doesn't work. Any ideas? I tried these entries in services start.

/usr/sbin/cru a WoL1 "10 * * * * arp -s IP MAC"
cru a WoL1 "10 * * * * arp -s IP MAC"

 

[ColinTaylor]

You did reboot the router didn't you?

Check that the script has run successfully by looking at the output of:

cru l

P.S. You can post your output if you want to. The MAC address and IP address are not sensitive information.

 

[T0mmy1977]

I did reboot the router. I get the following when I type cru l.

10 * * * * arp -s 192.168.1.101 MAC #WoL1#
10 * * * * arp -s 192.168.1.102 MAC #WoL2#
*/59 * * * * service restart_letsencrypt #LetsEncrypt#

 

[ColinTaylor]

I assume "MAC" is actually a MAC address in the correct format?

Those arp commands will only run once an hour at 10 minutes past the hour. From the reports I've read it seems like once an hour is to long. I suggest you use my suggested command ("*/10") to run it every 10 minutes.

 

[T0mmy1977]

I changed the timing to */10 and I get the output below, but it still fails to show as PERM when I run the arp command after 10 minutes.

*/10 * * * * arp -s 192.168.1.101 D8:BB:C1:8E:DD:33 #WoL1#
*/10 * * * * arp -s 192.168.1.102 04:7C:16:6E:6D:AC #WoL2#
30 12 * * * service restart_letsencrypt #LetsEncrypt#

 

[T0mmy1977]

Never mind, it did work! Thank you, sir! I just need to change the timing to */8 or something.