UDM Pro http issue

[lukasa1993]

i have server running in my lan on lets say 192.168.5.5 i have tailscale running on my udm pro which is 192.168.5.1 i have port open in udm so that 80/443 go to 192.168.5.5 and everything works when i am not on tailscale but when i am on tailsacle i use udm pro as exit node and i try to go to my domain port forwarding doesn't work it goes to 192.168.5.1 instead of 5.5 any idea what might cause this ?

[notheotherben]

To be honest, I'm struggling to sketch out your specific network topology and what those requests look like.

By my understanding, you've got something like the following:

graph LR
    You1(You) --Web Request - Works--> Server(192.168.5.5)
    Server --Reply--> You1
    You2(You) --Web Request to 192.168.5.5?--> Tailscale --> UDM --X--> Server
    UDM --Reply--> You2

Assuming that's correct, I'd like to understand what your "domain" is pointing to - are you making a request to 192.168.5.5 (i.e. is this a DNS A-record for 192.168.5.5) or are you making a request to your UDM's Tailnet domain?

[lukasa1993]

example.com -> UDM (ISP IP) -> 5.5

and from external network it works as it should

but from UDM when i request example.com it return UDM itself instead of 5.5

[notheotherben]

Gotcha, I suspect the answer is that your port forwarding is configured on your external WAN interface (since :80 and :443 are reserved on the UDM's local network interface(s) for the UDM UI). Tailscale, running in userspace networking mode, is going to be making requests from within the UDM's context and won't trigger those forwarding rules (it's the equivalent of running curl http://localhost on the UDM).

This is a bit of an edge case in the way you're using exit nodes and I'm not sure what the best solution to fix it would be given the circumstances, maybe a custom DNS server on your UDM which serves example.com A 192.168.5.5, overriding the public DNS resolution (although that's a particularly hacky workaround).

[lukasa1993]

oh i have custom dns i'll try it

[lukasa1993]

didn't work :( anyway as i understand its udm problem and not tailscale so i'll check with udm support thanks for quick response 👍

[catgirlinspace]

was there a fix for this issue? i have the same thing, i host lots of stuff on my home network that i expose to the internet and i can't access these when using my UDM as my exit node.