This article is letting IPv6 without a firewall. A few feedback: 1) Start by the "lower layer" If it's a physical server, start by reviewing all BIOS options

This article is letting IPv6 without a firewall. A few feedback: 1) Start by the "lower layer" If it's a physical server, start by reviewing all BIOS options, if it's virtual one you control, start by reviewing the host environment for the guest. 2) Follow from the bottom to the top Follow by review and secure the boot process. (Grub password, kernel modules loaded, kernel module options, kernel sysctl options. Follow by review the services started "even before starting nothing". Review what is accessible in the system to "anybody". Review what is accessible in the system to each "user". Many times a "user" is going to be listening to the hostile network in a port. Review what the system is going to do across the time, what is scheduled, which resources are assigned to which users (and their processes), what is going to be registered. 4) Does not limit or scrub any traffic It's not that we forget about IPv6 It's that such iptables, on any 1 core VPS, is vulnerable to DoS from a single IP (you don't need any distributed attack to put down that). A syn attack to the port 22 could be enough. In resume: When giving general security advisories, lets try that people build a secure system if they follow our tips. Not let open things like ping broadcast from our host, or IPv6