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Mark
Asked: 2011-10-22 15:38:52 +0800 CST

Netfilter/iptables - Accept connections from an DNS CNAME

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So I'm trying to accept connections on port 80 only from those IPs whose reverse DNS has a CNAME alias like, for example, *.test.mydomain.com:

1.1.1.1 resolves to boo.foo.com

and

*.test.mydomain.com CNAME boo.foo.com

then accept the connection.

Any tips?

domain-name-system ip cname-record iptables

1 Answers

  1. iptables has deal with IP addresses and subnets, not with DNS records.

    You have to write script, which will perform full zone transfer (something like dig -t AXFR test.mydomain.com), parse obtained zone file to get all CNAMEs from it, resolve them to IP addresses and add rules to iptables. Then you should place this script in cron.

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