forksand-it-manual/source/Firewalls.tex

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% Firewalls.tex
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% Fork Sand IT Manual
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% Copyright (C) 2018, Fork Sand, Inc.
% Copyright (C) 2017, Jeff Moe
% Copyright (C) 2016, 2017 Aleph Objects, Inc.
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% This document is licensed under the Creative Commons Attribution 4.0
% International Public License (CC BY-SA 4.0) by Fork Sand, Inc.
%
\Glspl{firewall} keep the bad packets out, mostly. And let some good packets out.

\section{Overview}
What is the network doing?

\begin{itemize}
 \item snort
 %\item MRTG
 %\item Aguri
\end{itemize}

\section{Authentication}
Two-factor authentication using TOTP.

\section{IPtables-firewall}
\subsection{Overview}
Most servers and workstations run GNU/Linux, which uses iptables.

\subsection{iptables}
iptables is part of the Netfilter project and has been included by default in
the Linux kernel for many years.

\begin{figure}[!htb]
\includegraphics[keepaspectratio=true,height=1.10\textheight,width=1.00\textwidth,angle=0]{www-netfilter.png}
 \caption{Netfilter Website}
 \label{fig:www-netfilter}
\end{figure}

\subsection{Requirements}
There are a lot of operating systems to consider to use as a \gls{firewall}...

Notes on some requirements in a \gls{firewall}.

\begin{itemize}
 \item Must be free software.
 \item The project must still be alive.
 \item Does it use a hardened kernel?
 \item How does it do security updates?
 \item Are there open security issues?
 \item Are there any CVEs?
 \item How are security issues handled?
 \item Is there a list of security issues?
 \item Does it have a wifi portal? (Should that be a separate box or in OpenWRT?)
 \item Does upstream https actually work?
 \item UTM - Unified Threat Management (e.g. snort, etc.)
 \item Load balancing between multiple upstreams (without BGP).
 \item Load balancing between dual local routers.
 \item Fail over to standby router (e.g. pfsync).
 \item ``Anti-virus'', SMTP, POP scans? Meh? (e.g. OpenBSD has greylist/tarpit.)
 \item Packet cleansing (e.g. tcp header randomization).
 \item Do we want DNS, DHCP, etc? Probably not?
 \item OpenVPN (built into router, or thru it?).
 \item Network graphing (MRTG, aguri, etc.)
 \item No broken ``community'' editions.
 \item Have mirrored server doing analysis?
 \item NAT options? cone, etc.
 \item Local system monitoring (e.g. system temp, hdd status, etc.)
 \item sshd
 \item GSM, pppd ?
 \item Two-factor authentication.
 \item snort, suricata
\end{itemize}


\subsection{\Gls{firewall} Operating Systems in Use}

\Large{\href{https://www.debian.org/}{Debian}}

Debian is used for nearly everything. It could easily be used as a
router-firewall. There are better, more tuned options.

Linux's iptables is used on servers.

\begin{figure}[!htb]
\includegraphics[keepaspectratio=true,height=1.10\textheight,width=1.00\textwidth,angle=0]{www-debian.png}
 \caption{Debian Website}
 \label{fig:www-debian-in-firewalls-chapter}
\end{figure}

\Large{Proxmox setups iptables-firewall}
During Proxmox installation on the nodes, \gls{firewall} is being confugured.
Some of nodes configurations can be found in chapter Free software under 
path apps/forksand-nodes-bootstrap/...

especially in two of files is mentioned:
\begin{minted}{sh}
# Firewalling is done through Proxmox.
cd /etc ; git add . ; git commit -a -m 'Use SharkTech NTP (others firewalled).'
\end{minted}

\begin{minted}{sh}
# Enable firewall.
# Datacenter --> shark4 (host) --> Firewall --> Add.
# Enable firewall for datacenter:
# Datacenter --> Firewall --> Options --> Firewall --> Yes
# Datacenter --> Firewall --> Options --> Firewall --> Yes
# Enable firewall for shark4:
# Datacenter --> Firewall --> Add.
\end{minted}

\textcolor[rgb]{0.80,0.00,0.00}{
Todo check other nodes, add other shark nodes if similar iptables-firewall related configs. \\
Find out why mention of firewall in hk1 node is discarded.
}

\begin{minted}{sh}
# Enable firewall.
# Datacenter --> truck (host) --> Firewall --> Add.
# Enable firewall for datacenter:
# Datacenter --> Firewall --> Options --> Firewall --> Yes
# Datacenter --> Firewall --> Options --> Firewall --> Yes
# Enable firewall for truck:
# Datacenter --> Firewall --> Add.
\end{minted}

Also Nextcloud chapter mentiones configs of iptables-firewall \ref{ssec:nextcloudfirewall} on p.\pageref{ssec:nextcloudfirewall}.

Also certain Ansible including virtual machines enable iptables configuratiion.
For example ansible-debian-male contains mikegleasonjr.firewall.
\href{https://github.com/mikegleasonjr/ansible-role-firewall}{
ansible firewall\char`_v4\char`_configure example on github
}
May be browsed in Free software chapter under path apps/ansible-debian-mail/roles/