| `os_security_kernel_enable_module_loading`| true | true if you want to allowed to change kernel modules once the system is running (eg `modprobe`, `rmmod`)|
| `os_security_kernel_enable_sysrq`| false | sysrq is a 'magical' key combo you can hit which the kernel will respond to regardless of whatever else it is doing, unless it is completely locked up. |
| `os_security_kernel_enable_core_dump`| false | kernel is crashing or otherwise misbehaving and a kernel core dump is created |
| `os_security_suid_sgid_enforce`| true | true if you want to reduce SUID/SGID bits. There is already a list of items which are searched for configured, but you can also add your own|
| `os_security_suid_sgid_blacklist`| [] | a list of paths which should have their SUID/SGID bits removed|
| `os_security_suid_sgid_whitelist`| [] | a list of paths which should not have their SUID/SGID bits altered|
| `os_security_suid_sgid_remove_from_unknown`| false | true if you want to remove SUID/SGID bits from any file, that is not explicitly configured in a `blacklist`. This will make every Ansible-run search through the mounted filesystems looking for SUID/SGID bits that are not configured in the default and user blacklist. If it finds an SUID/SGID bit, it will be removed, unless this file is in your `whitelist`.|
| `os_security_packages_clean'`| true | removes packages with known issues. See section packages.|
| `ufw_manage_defaults` | true | true means apply all settings with `ufw_` prefix|
| `ufw_ipt_sysctl` | '' | by default it disables IPT_SYSCTL in /etc/default/ufw. If you want to overwrite /etc/sysctl.conf values using ufw - set it to your sysctl dictionary, for example `/etc/ufw/sysctl.conf`
| `ufw_default_input_policy` | DROP | set default input policy of ufw to `DROP` |
| `ufw_default_output_policy` | ACCEPT | set default output policy of ufw to `ACCEPT` |
| `ufw_default_forward_policy` | DROP| set default forward policy of ufw to `DROP` |
# Make sure to ignore ECHO broadcasts, which are only required in broad network analysis.
net.ipv4.icmp_echo_ignore_broadcasts: 1
# There is no reason to accept bogus error responses from ICMP, so ignore them instead.
net.ipv4.icmp_ignore_bogus_error_responses: 1
# Limit the amount of traffic the system uses for ICMP.
net.ipv4.icmp_ratelimit: 100
# Adjust the ICMP ratelimit to include ping, dst unreachable,
# source quench, ime exceed, param problem, timestamp reply, information reply
net.ipv4.icmp_ratemask: 88089
# Disable IPv6
net.ipv6.conf.all.disable_ipv6: 1
# Protect against wrapping sequence numbers at gigabit speeds
net.ipv4.tcp_timestamps: 0
# Define restriction level for announcing the local source IP
net.ipv4.conf.all.arp_ignore: 1
# Define mode for sending replies in response to
# received ARP requests that resolve local target IP addresses
net.ipv4.conf.all.arp_announce: 2
# RFC 1337 fix F1
net.ipv4.tcp_rfc1337: 1
```
Alternatively you can change Ansible's [hash-behaviour](https://docs.ansible.com/ansible/intro_configuration.html#hash-behaviour) to `merge`, then you only have to overwrite the single hash you need to. But please be aware that changing the hash-behaviour changes it for all your playbooks and is not recommended by Ansible.
The preferred way of locally testing the role is to use Docker. You will have to install Docker on your system. See [Get started](https://docs.docker.com/) for a Docker package suitable to for your system.
You can also use vagrant and Virtualbox or VMWare to run tests locally. You will have to install Virtualbox and Vagrant on your system. See [Vagrant Downloads](http://downloads.vagrantup.com/) for a vagrant package suitable for your system. For all our tests we use `test-kitchen`. If you are not familiar with `test-kitchen` please have a look at [their guide](http://kitchen.ci/docs/getting-started).
* [Deutsche Telekom, Group IT Security, Security Requirements (German)](http://www.telekom.com/static/-/155996/7/technische-sicherheitsanforderungen-si)
