Hey Future Me,

After hours and hours of broken internet access we finally got the DNS server up and running consistently for days now! This process was very difficult due to the nature of this network change. When flipping the switch to turn this on if we didn’t get it exactly right then internet no longer works making google queries to troubleshoot issues impossible. After a combination of countless articles on DNSMASQ and me poking the conf file I have finally managed to make it work.

love,

past you!

What I wanted to accomplish was:

• My router would have a static IP of 192.168.1.1
• The Raspberry Pi running the DNSMASQ server would have a static IP of 192.168.1.2
• The Raspberry Pi running the DNSMASQ server would have a host name of DNSMASQ
• My desktop would have a static IP of 192.168.1.5
• All DNS queries would go to the raspberry pi for DNSMASQ to handle
• The DNSMASQ server would hand out IP addresses instead of my router (this forces DNS lookups to go to the DNSMASQ server without having to configure each individual computer as a part of the DHCP protocol neogations with clients)
• Connecting to other computers on my network  would only require the name and not an IP address

**Static IP is not something that requires a dnsmasq server and if you have a router that supports DNS configuration or if it is flash-able with DD-WRT it would also get all this functionality without having to create a separate server. If you are wondering why I went through all this trouble it is because my router is not a DD-WRT flash-able router and I found 4 raspberry pi’s laying around that didn’t have a purpose. Also I like the idea of having a S.O.C. architecture using pi’s as they can be written to a file, saved and recreated in a few minutes. As for the remaining three raspberry pi’s I am still deciding on a use but I am playing around with the idea of using them to compute the meaning of life and perhaps even create a super intelligent sentient being to prove humans aren’t all what their cracked up to be but I will save that for another blog post.

Setting up the Pi

Step 1 – Change the host name

This will change the name seen on the network for the device. In my case I chose to use DNSMASQ as the name instead of the default of “raspberrypi”. There is a really good article on how to do this here: Changing Host Name

Step 2 – Setting Static IP of Pi

There is an article on this as well which you will find here. Follow the instructions as stated with the following changes:

• Remove this line static domain_name_servers=192.168.0.1
• Set this line static routers=192.168.0.1 to whatever your routers current IP is most likely either 192.168.1.1 or 192.168.0.1. In my case it was 192.168.1.1.

Step 3 – Install DNSMASQ

Run the following command to install dnsmasq on your pi.
apt-get install dnsmasq

Step 4 – Configure DNSMASQ

This is were things can get really hairy. Like any software every made the configuration allows for you to do anything and everything in an infinite number of combinations. That being said I carefully documented all the changes I needed after every “poke” of the config file that I took. This was extremely time consuming but resulted in a much better understanding of what different settings do. I now know that when the explanations for such config values describe words that I do not understand it means it will break my network if I change it because I have no idea what I am doing. I also suggest you rename the existing config file using the below and then start with a blank one.
sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.old
sudo nano /etc/dnsmasq.conf

Below is an exact copy of my conf file:

#BEGIN JORDANG
#This tells DNSMASQ to send any queries it does not already know to 8.8.8.8
server=8.8.8.8
#This tells DNSMASQ to send any queries it does not already know to 8.8.4.4
server=8.8.4.4
#Size of cache in KB
cache-size=4096
#Must be present and match domain and have the two slashes
local=/jordang.net/
#Expands the hosts when an entry comes in without a fully qualified domain name
#e.g. winbeast would get translated to winbeast.jordang.net
expand-hosts
#The domain the DNSMASQ represents internally to all the machines that query it
domain=jordang.net
#This is the range of the IP addresses it is allowed to get out,
#along with a sub net mask and a lease of 14 days per client
dhcp-range=192.168.1.3,192.168.1.254,255.255.255.0,14d
#This option is for windows 7/Vista/XP to fix a known issue with them
dhcp-options=252,"\n"
#Tell dnsmasq to log to this file
log-facility=/var/log/dnsmasq.log
#Forces dnsmasq to log async when able to not slow queries
log-async
#Will log all dhcp requests e.g. any ip addresses it hands out
#can be commented out when this is working
log-dhcp
#Logs the DNS request which includes the client that asked, the DNS name, and the #IP address that was returned can be commented out when this is working
log-queries
#This says when a host connects who says its name is WINBEAST then give it this ip #address and allow the client to have the ip address indefinitley
dhcp-host=WINBEAST,192.168.1.5,infinite
#END JORDANG


Step 5 – Turn off your routers DHCP server

This part depends on your router. My router had an advanced section where I could turn off the DHCP server and let it be handled by another component on the network. This is where you are setting the bridge on fire before you start crossing it. Try not to plummet to your death.

Step 6 – Don’t bite the tail

After the DHCP server is turned off things will start to disconnect but will hopefully reconnect and everything will be magical and perfect. As a debugging measure run the following command on the pi locally. This will display lines being appended to the log on the console so you can monitor what your DNSMASQ is doing.
sudo tail -f /var/log/dnsmasq.log

Step 7 – Setting the bridge on fire is taking too long so lets just cut it instead

On a windows machine run the following command in a command prompt with administrator privileges:
ipconfig /release
This causes the computer to try and renew it’s lease on the IP address it is on. This will hopefully hit the new DNSMASQ server after the router responds with “I cannot help you”. On my machine I got a notification that there was a network connection but no internet access and to let windows troubleshooter try to fix it. The trouble shooter reset the network adapter which then forced it to the correct IP and all was working.

Step 8 – Verify and “Prodernize” you DNSMASQ Config

On a windows machine you can verify that all is working by running the following command in the command prompt.
ipconfig /all
This should display among other things the DNS suffix which we set in the DNSMASQ’s conf file for domain(jordang.net), the DNSMASQ server IP address which we set to in the pi’s dhcpcd.conf file as a static IP (192.168.1.2), and the Default gateway which would of been the IP of our router(192.168.1.1). You should also be able to address any device on the network with its name as opposed to its IP address. Assuming all is well go into your dnsmasq.conf file located in /etc/ on your pi and remove the lines for logging so that you do not bog down your pi with frivolous logging that is no longer helpful.

Step FUBAR – Here are some issues I had and how I solved them

• Run the below command on the pi to see if it has an IP address of 192.168.1.2 on the interface it is connected with:
  ifconfig /all
• If not it could be that you did not remove the static domain_name_servers from your dhcpcd.conf file when setting the host name and static IP or that you didn’t setup the dhcpcd.conf file at all giving your device a static IP address. See step 2.
• If the above command shows the pi has the appropriate IP address then check the log using the tail command mentioned earlier to see if any other clients besides itself are making requests. Also check to see if the pi can reach the outside world by running the below command.
  ping google.com
• If It is not able to reach google this is usually related to it not having an IP address and the static domain_name_servers being set from the tutorial I mentioned previously. See step 2.
• If it is able to reach google then try restarting the dnsmasq server. I found that anytime my pi reboots before any of my clients can connect I have to restart the DNSMASQ service with the below command.
  sudo service dnsmasq restart
  I set this up with a CRON task on the pi to happen a few seconds after a boot in case of a power outage so I do not have to remember. That is outside the scope of this article and will be a future post.
• Another common issue I had was using the number pad when entering digits only to have it recognize it as commands and causing malformed conf files. It is a good idea to look at the conf files again to be sure nothing strange jumps out at you. If all else fails disconnect the pi from the network, reset the dnsmasq.conf file with the previous version, turn on DHCP on your router and try again. I eventually got all this working on the 15th or so attempt.