Known limitations
Below, you will find information on devices, software, and configurations that are incompatible with Cloudflare WARP.
Split Tunnel exclusions on Windows
Windows WARP version 2023.3 and higher require the following addresses to be excluded from the WARP tunnel, or else the client will be unable to connect. If you removed these routes from the default Split Tunnel Exclude list, they will need to be re-added:
224.0.0.0/4ff01::/16ff02::/16ff03::/16ff04::/16ff05::/16
Windows Server
The WARP client does not run on Windows Server. Refer to the downloads page for a list of supported operating systems.
Multi-user support on Windows
The WARP client does not support multiple users on a single Windows device. WARP uses hard-coded global paths to store settings and keys and does not save information on a per-user basis. Therefore, after one user logs into WARP, their settings will apply to all traffic from the device.
4G/5G embedded modules
Because of how the WARP client instantiates the local DNS Proxy, it is incompatible with 4G/5G cellular adaptors which have IPv6 enabled. To run WARP on these devices, you will need to disable IPv6 on the system.
Comcast DNS servers
Comcast DNS traffic to 75.75.75.75 and 75.75.75.76 cannot be proxied through WARP. This is because Comcast rejects DNS traffic that is not sent directly from the user’s device.
To work around the issue, you can either:
- Create a Split Tunnel rule that excludes
75.75.75.75/32and75.75.75.76/32from WARP. - Configure your device or router to use a public DNS server such as
1.1.1.1.
HP Velocity
The HP Velocity driver has a bug which will cause a blue screen error on devices running WARP. HP recommends uninstalling this driver.
Cisco Meraki
Cisco Meraki devices have a bug where WARP traffic can sometimes be identified as Statistical-P2P and de-prioritised or dropped entirely. To resolve the issue, disable Statistical-P2P on the Cisco Meraki device.
Windows Teredo
The Windows Teredo interface conflicts with the WARP client. Since Teredo and WARP will fight for control over IPv6 traffic routing, you must disable Terado on your Windows device. This allows the WARP client to provide IPv6 connectivity on the device.