I have a bit of an odd issue, which I was hoping someone may be able to help with.
I have an IPFire system setup, which is pretty much vanilla and out of the box configuration - no proxy, no firewall changes. The LAN output connects to a switch which also connects to some TP Link Deco mesh units for WiFi (in access point mode). I also have another router (TP Link MR-6400) connected to the switch via its WAN port which creates a competely segregated network with a different subnet (TL-MR6400 | 300 Mbps Wireless N 4G LTE Router | TP-Link United Kingdom).
When clients are connected to the IPFire network (either via the Deco or via the ethernet switch), there are a number of microsoft sites which can not be accessed (e.g. clients don’t get their microsoft credentials when starting Outlook, or cannot access Microsoft Store).
If clients connect to the MR-6400 (which still routes to the internet via the IPFire network), they CAN get access to these sites, which is really strange.
Has anyone got any thoughts on what I should check to identify the potential issue here?
On one of the clients, I went to the proxy settings and disabled the option to “Automatically detect settings”, and things seem to work now on that individual client.
My IPFire install used to have a transparent proxy on red (with a basic URL filter), but after a system crash (during an update), and I reinstalled the whole system. On the new install, I didn’t bother implementing the transparent proxy.
For some reason, clients may be trying to connect to a proxy that no-longer exists.
Is there a way I can check if there are any strange proxy settings on the IPFire system (even thought they aren’t showing in the IPFire WebGUI?