Hi, dwagner, I'm probably late, but the problem you are facing is most likely related to the fact that dnsmasq is not told by default to use any external dns servers.
You can force it to use google's just by adding these 2 lines to the end of the /etc/dnsmasq.conf:
server=8.8.8.8
server=8.8.4.4
resolv.conf by default is set to 127.0.0.1, meaning that all name resolutions will be handled by the dns server located at 127.0.0.1, which is your instance of dnsmaq. Dnsmasq in turn, with these 2 lines, is told to forward dns queries to those external dns servers.
This may be still not be an ideal setup (probably if you also need to resolve local domain names successfully), but it currently suits my needs.
Just for the record, I have my laptop with wifi turned off, internet fed exclusively by an ethernet cable coming from the router, I disconnect the ethernet (I run out of internet), connect the turtle with default network settings, and connect the ethernet cable into the turtle. After 10 seconds or so, I can browse the internet as usual, and all traffic is coming to/from the turtle, even dns queries.
You can even see that the dns server for my adapter was indeed set to turtle's:
Ethernet adapter LAN Turtle:
Connection-specific DNS Suffix . : lan
Description . . . . . . . . . . . : Realtek USB FE Family Controller #2
Physical Address. . . . . . . . . : XX-XX-XX-XX-XX-XX
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : fd8f:cf7a:45fa::2b1(Preferred)
Lease Obtained. . . . . . . . . . : Wednesday, June 21, 2017 1:31:25 AM
Lease Expires . . . . . . . . . . : Thursday, June 22, 2017 1:31:25 AM
IPv6 Address. . . . . . . . . . . : fd8f:cf7a:45fa:0:80e2:f131:6eab:1fc6(Preferred)
Temporary IPv6 Address. . . . . . : fd8f:cf7a:45fa:0:5066:45c6:2e58:f2f0(Preferred)
Link-local IPv6 Address . . . . . : fe80::80e2:f131:6eab:1fc6%138(Preferred)
IPv4 Address. . . . . . . . . . . : 172.16.84.117(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Wednesday, June 21, 2017 1:31:30 AM
Lease Expires . . . . . . . . . . : Wednesday, June 21, 2017 1:32:21 PM
Default Gateway . . . . . . . . . : 172.16.84.1
DHCP Server . . . . . . . . . . . : 172.16.84.1
DHCPv6 IAID . . . . . . . . . . . : -1979654068
DHCPv6 Client DUID. . . . . . . . : XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX
DNS Servers . . . . . . . . . . . : fd8f:cf7a:45fa::1
172.16.84.1
NetBIOS over Tcpip. . . . . . . . : Enabled
Connection-specific DNS Suffix Search List :
home
And turtle in turn redirects every query to 8.8.8.8, falling back to 8.8.4.4 in case 8.8.8.8 becomes unreachable.
Hope it helps.
