Time bases iptables rules

Question: How can I restrict/allow access to certain service on timely basis with iptables? For example restrict access to SSH between 7:00 pm – 8:00 am on weekdays?

Answer: You are welcome to use iptables patch-o-matic extension (pom or p-o-m) that allows you to match a packet based on its arrival or departure (for locally generated packets) timestamp. The syntax is the following:

iptables RULE -m time –timestart TIME –timestop TIME –days DAYS -j ACTION


–timestart TIME: Time start value (format is 00:00-23:59)
–timestop TIME: Time stop value (the same format)
–days DAYS: a list of days to apply, from (format: Mon, Tue, Wed, Thu, Fri, Sat, Sun).

To add the rule stated in the question use the following command:

iptables -A INPUT -p tcp -d –dport 22 -m time –timestart 19:00 –timestop 8:00 -days Mon,Tue,Wed,Thu,Fri -j DROP

Hope it helps!


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