Tag Archives: DNS

Let’s say we want to add reverse DNS delegation for the IP block The first step of the configuration is on the nameserver, BIND on our case. Create the relevant reverse DNS file on /var/named/rev and then edit the file: cd /var/named/rev touch 123.234.12 vim 123.234.12 The file contents should be like the following: […]

Everything started with a few queries of isc.org thrugh open DNS servers located at our data center. Searching through the net we found that we are not the victims but a part of  uncomprimised sources of  a huge DDoS attack. A 60 byte query will turn into 50 times larger data directed to victims IP […]

If you own your DNS servers, you should probably want to close recursive queries being gathered from your servers. In named.conf edit the options directive and add: options { allow-transfer {Secondary Server IP; }; allow-recursion {; A.B.C/24; }; }; In secondary server: add to options: allow-transfer { none; }; allow-recursion {; A.B.C/24; };