How can I get DNS resolution on-line and offline for virtual machine and local app using dnsmasq or similar
mDNSResponder and dnsmasq have to run both: dnsmasq is the lightweight DNS-server (and DHCP/Router) and mDNSResponder is responsible for all local queries.



To set up dnsmasq in OS X in your environment properly do the following:

Remove any DNS-server in the network preferences of the dnsmasq host (your MacBook Air) except 127.0.0.1. 

Remove any DNS-server in the network preferences of the VMs in use and replace them by the IP-address of the VM-host (your MacBook Air).

Remove any file in /etc/resolver/. Usually they aren't necessary.
You may keep them but then they probably should have this form:

/etc/resolver/rab with the content

nameserver    127.0.0.1


/etc/resolver/tig with the content

nameserver    127.0.0.1


The logic behind this is mentioned in resolver(5):


  domain
           Domain name associated with this resolver configuration. This option is normally not     required by the Mac OS X DNS search system when the resolver configuration is read from a     file in the /etc/resolver
       directory.  In that case the file name is used as the domain name.      However, domain must be provided
       when there are multiple resolver clients for the same     domain name, since multiple files may not exist
       having the same name.  See the SEARCH     STRATEGY section for more details.


Then edit /usr/local/etc/dnsmasq.conf and add/modify

server=/rab/192.168.0.2 #your main IP-address or 127.0.0.1
server=/tig/192.168.0.2 #your main IP-address or 127.0.0.1
server=8.8.8.8 #forwarder
addn-hosts=/usr/local/etc/hosts/hosts.conf


Now add the hosts.conf file in /usr/local/etc/hosts/ with the content:

127.0.0.1   localhost
192.168.56.1    abc.rab
192.168.56.2    abc.tig


Then restart dnsmasq with launchctl to load the new conf files.



Since your Windows VM already is in the bridged Wi-Fi network you can completely dump the host-only network and modify /usr/local/etc/hosts/hosts.conf:

127.0.0.1   localhost
192.168.0.2 abc.rab #IP-address of the MacBook Air Wi-Fi interface
192.168.0.3 abc.tig #IP-address of the Windows bridge interface