Use DietPi as HotSpot routing (some) requests to Tailscale

General Discussion
1

Hi all, I need to access my 3D Printer on Tailscale address via wifi client not supporting Tailscale.
I set up Tailscale on my DietPi.
I set up hotspost on my DietPi.
Now I have:
eth0: my local lan
wlan0: my WiFi Hotspot
Tailscale0: my Tailscale connection

I need to reach the Tailscale address: 100.100.100.100 from my not supporting Tailscale device.
My DietPi can, obviously, ping 100.100.100.100.
I tried:
ip route add 100.100.100.100/32 dev tailscale0 but it does not work.

Suggestions?

Thanks

Luca

2

What does traceroute 100.100.100.100 on the wifi client show?

3

Hallo, thx for your answer.
I made several more test using TCPDump and my WiFi Client stops at DietPi.
Analyzing TCPDump, the packet is correctly forwarded, but I do not receive echo.

Here is an example (NOTE that 192.168.42.12 is the WiFi Client address):

13:28:54.595452 wlan0 In  IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 59, seq 1, length 64
13:28:54.595642 tailscale0 Out IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 59, seq 1, length 64
13:28:55.581876 wlan0 In  IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 60, seq 1, length 64
13:28:55.581981 tailscale0 Out IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 60, seq 1, length 64
13:28:56.584694 wlan0 In  IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 61, seq 1, length 64
13:28:56.584867 tailscale0 Out IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 61, seq 1, length 64
13:28:57.585659 wlan0 In  IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 62, seq 1, length 64
13:28:57.585844 tailscale0 Out IP 192.168.42.12 > 100.121.154.10: ICMP echo request, id 62, seq 1, length 64

Looks like if I do not have a reverse route on my 100.121.154.10 client.

4

Indeed, it looks like tailscale doesn’t know how to route back to 192.168.42.12. Because tailscale only knows about your Raspberry Pi IP address.
Did you set up tailscale to route to your local network? (probably subnet 192.168.42.0/24)

5

This is the official KB article for sub net routing on Tailscale Subnet routers and traffic relay nodes · Tailscale

1 Like
6

Ok, first of all, thx for your support.
Now everything SHOULD work, but I cannot use subnet router.
I found an article on Tailscale:

Sharing & Subnets (subnet routers) 
Sharing does not expose subnet relayed traffic to the other network. We may introduce support for sharing subnets at a later time, via an opt-in process.

I will wait for this improvement :slight_smile:
Thanks to everybody.

Luca

7

hmm strange, the KB article I shared exactly describe how to enable subnet routing on Tailscale. Maybe you can contact thier support for clarification. :thinking: