Crontab not working

Hello,

I advise you to proceed like that (don't use pkill tcpdump 0,15,30,45 ... instead use timeout as shown below):

So first of specify when you want to trigged your tcpdump, you can use an online generator:

https://www.freeformatter.com/cron-expression-generator-quartz.html

Then use command

timeout (sec)

in order to setup how many times you want to capture (suppose 5 sec), you will obtain (crontab every 10 minutes):

*/10 * * * *

timeout 5

tcpdump -ni 0.0:nnnp -s0 host x.x.x.x or host y.y.y.y or host z.z.z.z -w /var/tmp/2518/2518_v4_`date +%Y%m%d%H%M%S`.pcap

Keep me update regards