Cannot connect to server via Wifi on Mobile Devices

Help
1

Hello,

I have a pretty strange issue that I’m not sure what would be causing it. I am hosting Vaultwarden in a docker droplet on Digital Ocean and proxying it using Caddy and it works perfectly fine, apart from on Wifi on my mobile devices (iPhone and iPad). It comes up with "Cannot open the page because it could not connect to the server’.

It works absolutely fine via the same wifi on my laptop and desktop but not on mobiles devices. If I use mobile data rather than wifi however, then the mobile devices connect just fine! I’m not sure what information might be needed in order to trouble shoot, so just let me know that you need!

Cheers

2

I’m not sure if this is something we can help you with.
Only thing i can think of is either DNS on those devices via WiFi do not work well. Or something is blocking it for only the mobile devices via WiFi.

But if you say it does work via WiFi on your laptop and they use the same DNS servers. Then i don’t know.

It at least doesn’t seem te be a Vaultwarden issue.

3

Maybe something about Cypher Suites on the proxy level? I know that some older mobile devices are unable to connect to my server, since i chose a pretty strict selection of allowed cypher suites

4

What clients are you using on mobile vs laptop/desktop?

I would assume you are using the mobile app when on mobile and either cannot connect on WiFi or are able to connect on mobile data as you mentioned.
Do you connect on PC with the application or the web vault?

I agree with @BlackDex it’s most likely DNS, and am wondering if you may have an internal DNS with your router or something such as a pi-hole server acting as DNS, especially in the case you have a split brain DNS and use the same network internally as your external DNS.
i.e using the same domain for internal and external access and subdomains (internal DNS server domain.com with records for sub1.domain.com, sub2.domain.com; external public DNS server also has domain.com, sub3.domain.com, sub4.domain.com)
vs using a separate subdomain for internal access only (external public DNS server domain.com, sub1.domain.com, sub2.domain.com; internal DNS corp.domain.com, sub1.corp.domain.com, sub2.corp.domain.com)

5

Is IPv6 configured correctly on the server / router / iOS devices? You might also want to check the SSL settings of your server for issues.