(networking) added sample config for dnsmasq and note on how to enable

routing

dnsmasq.conf

@@ -0,0 +1,59 @@
+# Configuration file for dnsmasq.
+#
+# Format is one option per line, legal options are the same
+# as the long options legal on the command line. See
+# "/usr/sbin/dnsmasq --help" or "man 8 dnsmasq" for details.
+
+# Listen on this specific port instead of the standard DNS port
+# (53). Setting this to zero completely disables DNS function,
+# leaving only DHCP and/or TFTP.
+#port=5353
+
+# The following two options make you a better netizen, since they
+# tell dnsmasq to filter out queries which the public DNS cannot
+# answer, and which load the servers (especially the root servers)
+# unnecessarily. If you have a dial-on-demand link they also stop
+# these requests from bringing up the link unnecessarily.
+
+# Never forward plain names (without a dot or domain part)
+domain-needed
+# Never forward addresses in the non-routed address spaces.
+bogus-priv
+
+# Uncomment this to filter useless windows-originated DNS requests
+# which can trigger dial-on-demand links needlessly.
+# Note that (amongst other things) this blocks all SRV requests,
+# so don't use it if you use eg Kerberos, SIP, XMMP or Google-talk.
+# This option only affects forwarding, SRV records originating for
+# dnsmasq (via srv-host= lines) are not suppressed by it.
+filterwin2k
+
+# If you want dnsmasq to listen for DHCP and DNS requests only on
+# specified interfaces (and the loopback) give the name of the
+# interface (eg eth0) here.
+# Repeat the line for more than one interface.
+interface=enp3s0
+
+# Set this (and domain: see below) if you want to have a domain
+# automatically added to simple names in a hosts-file.
+expand-hosts
+
+# Set the domain for dnsmasq. this is optional, but if it is set, it
+# does the following things.
+# 1) Allows DHCP hosts to have fully qualified domain names, as long
+#     as the domain part matches this setting.
+# 2) Sets the "domain" DHCP option thereby potentially setting the
+#    domain of all systems configured by DHCP
+# 3) Provides the domain part for "expand-hosts"
+domain=quakers
+
+# Uncomment this to enable the integrated DHCP server, you need
+# to supply the range of addresses available for lease and optionally
+# a lease time. If you have more than one network, you will need to
+# repeat this for each network on which you want to supply DHCP
+# service.
+dhcp-range=10.0.0.2,10.0.0.254,12h
+
+
+# For static ip assignment use the option `dhcp-host`
+#dhcp-host=11:22:33:44:55:66,192.168.0.60

network.md

@@ -0,0 +1,22 @@
+# network
+
+This document holds network related notes.
+
+<!--toc:start-->
+- [network](#network)
+  - [enable routing](#enable-routing)
+<!--toc:end-->
+
+
+## enable routing
+
+To enable routing permanently add a file `/etc/sysctl.d/` with the following contents:
+
+```ini
+net.ipv4.ip_forward=1
+```
+
+## simple gateway with nftables
+
+> **WARNING:** do not use this configuration for an edge router (directly connected to the internet/isp)!
+