After the implementation of DNS and DNSSEC (see the last posts) it is good to do some reconnaissance attacks against the own DNS servers. Especially to see the NSEC or NSEC3 differences, i.e., whether zone walking (enumeration) is feasible or not.
For many different kinds of DNS reconnaissance the tool dnsrecon can be used. In this post I will focus on the
-z option which is used for DNSSEC zone walking, i.e., walk leaf by leaf of the whole DNS zone.
Continue reading How to walk DNSSEC Zones: dnsrecon →
One core topic when designing firewall policies is the following question: Is ping a security attack? Should ICMP echo-request messages be blocked in almost any directions?
My short answer: Ping is your friend. :) You won’t block hackers if you block ping. Instead, ping is quite useful for network administrators checking basic network connectivity. That is: I suggest allowing ping anywhere around, accept incoming connections from the Internet to the trusted networks.
Here comes a discussion:
Continue reading Why Ping is no Security Flaw! (But your Friend) →