this documentation is available on:

https://www.github.com/mondomom/dnsmasq.git

dnsmasq

config files and NetSIG DNSMasq presentation documentation

Note that I'm not using DNSMasq for dhcp. That's taken care of by my router (for now)

I have a lot of Pi's, and a fair few VMs in addition to the usual workstations and laptops.

• it was frustrating keeping track of each IP address

• there are some things I'd like to do that would benefit from being able to use FQDNs on my network.

• I had a spare Raspberry Pi 3B not doing anything. It's turned out to be more than powerful enough for dnsmasq.

• This project was quick and easy, so I could get on to the stuff I really wanted to play with.

Installation

install dnsmasq application, and dnsutils so you can see what's going on

sudo apt install dnsmasq
sudo apt install dnsutils

Server Configuration

There are only two files that need to be edited:

one is /etc/dnsmasq.conf and the other is /etc/hosts

cool "grep" command to show config files without comments or empty lines:

grep -v "^#" dnsmasq.conf | grep -v "^$"

Here's dnsmasq.conf:

lynn@fedora:~/MyCode/dnsmasq$ grep -v "^#" dnsmasq.conf | grep -v "^$"
server=8.8.8.8
local=/lpnet.ca/
domain=lpnet.ca
cache-size=1500
cname=mywiki.lpnet.ca,wendy.lpnet.ca
dhcp-mac=set:client_is_a_pi,B8:27:EB:*:*:*
dhcp-reply-delay=tag:client_is_a_pi,2

Note, though, that the dnsmasq.conf file contains lots of good info

Here's /etc/hosts:

127.0.0.1       localhost
::1             localhost ip6-localhost ip6-loopback
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters


# real hardware
10.0.0.2                sammy sammy.lpnet.ca
10.0.0.5                accumulus accumulus.lpnet.ca
10.0.0.7                wynn wynn.lpnet.ca
10.0.0.8                wynn11 wynn11.lpnet.ca
10.0.0.9                hyperbox hyperbox.lpnet.ca

# VMs
10.0.0.26               wendy wendy.lpnet.ca
10.0.0.28               harvey harvey.lpnet.ca

# Raspberry Pi's
10.0.0.30               blueberry blueberry.lpnet.ca
10.0.0.32               cherry cherry.lpnet.ca
10.0.0.35               raspberrypi raspberrypi.lpnet.ca
10.0.0.36               cranberry cranberry.lpnet.ca
10.0.0.37               blackberry blackberry.lpnet.ca

# Kubernetes Stuff
10.0.0.81               katy1 katy1.lpnet.ca

There is a service that runs on the server called dnsmasq and it's controlled by systemd (sorry, everyone ;)

systemctl status dnsmasq.service

I found out that dnsmasq will also do cnames. I have a wiki, mywiki, that I want to access by the wiki name (mywiki.lpnet.ca) instead of theserver name (wendy.lpnet.ca).

in the /etc/dnsmasq.conf file, I added cname=desired_name,real_name

cname = mywiki.lpnet.ca,wendy.lpnet.ca

First, restart the service:

systemctl restart dnsmasq.service

Now I can see where the cname directs to:

nslookup mywiki.lpnet.ca

• a bit of an interesting gotcha - I set up a cname, then tried it ping it from the dnsmasq server. It didn't work because I hadn't set the dns server in resolv.conf.
• I tried it from another of my systems and it worked fine.
• bonus feature - you can add multiple cname lines to the .conf file

##Host Configuration

• each host in my network (the way it is so far) needs to have the DNS IP address added to it.
• I've found that it's easier to do this on each host once, than forever looking up addresses, but YMMV
• for most Linux type flavours that I've worked with, editing /etc/resolv.conf works OK. Once you get into bookworm, though, you need to deal with network manager. There is a command line tool called nmtui that is a sort of graphical command line tool that makes dealing with network manager way easier than the included nmcli command.

Another thing to note:

DNS seems to need some kind of domain name. There seems to be only one strictly legal unregistered domain name that someone can use for their home network, and that's home.arpa (RFC 8375) assigned in 2018

There is some indication that .local might still be OK but there are issues with multicast-DNS (?? What is that, anyway??)

.play and .home have been taken

.example, .invalid, .localhost, and .test are also reserved names, but I didn't like any of them, so I bought lpnet.ca

Conclusion

• setting up dnsmasq was quick and easy
• I only have to enter IP addresses once into the hosts file on the dnsmasq server
• It could be added onto in the future, if I decide to add dhcp
• Also, dnsmasq is used with some other services so getting familiar with it could have added benefits

=======
== Note that I'm not using DNSMasq for dhcp. That's taken care of by my router (for now).
== cool picture to find:
RPiSystem.png