Hi,
I’m looking for a way to block Cloudflare’s WARP service from my network.
I’m aware cloudflare WARP can be used to filter internet, but my kids instead use it to bypass DNS filtering on my network and I was hoping there would be a way to block the service entirely.
Thanks.
WARP IPs are part of the same ASN as Cloudflare’s websites so you couldn’t block it without also blocking most Cloudflare sites - although, if your router is super configurable, you could filter based the equivalent of (ASN = 13335 AND IP in_range 8.0.0.0/8) since WARP seems to only use IPs they bought from Level 3 which are all part of that class A (although CF makes no guarantee to always use this IP range).
Your best bet to controlling VPN usage is using MDM-type software, or simply the built-in parental controls available on major devices: Apple - Google Play - Microsoft Family Safety
Oh…that’s just the beginning. Firefox and Brave let you add DoH with several services. Now I have some sympathy for for corporations dealing with the same thing.
Thankfully, my kids aren’t yet advanced enough to discover VPNs and such. At which point I will have lost the battle on that front because there’s an endless amount of ways to circumvent any such “parental control” . Thankfully the longer-running “let’s make good choices” battle is tipping in my favor.