IP 없이 부팅하기 위한 crontab이 작동하지 않습니다.

내 웹 서버에 문제가 있습니다. 일반적으로 No-IP-DUC를 시작합니다 sudo noip2. cronjob을 사용하여 자동화하려고 합니다. 을 사용하여 crontab -e다음 파일을 만들었습니다.

# Edit this file to introduce tasks to be run by cron.
#
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
#
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').#
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
#
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
#
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
#
# For more information see the manual pages of crontab(5) and cron(8)
#
# m h  dom mon dow   command

@reboot cd /home/username/noip-2.1.9-1 && sudo noip2

작동하지 않으며 이유를 모르겠습니다. 누군가가 나를 도울 수 있다면 좋을 것입니다.