Step of reproduce
- Use a browser with http/3 support (Firefox/90.0 for me)
- Enable CLoudflare Warp (I am using Warp+ on windows with version
1.5.461.0
). - Access
https://www.cloudflare.com/cdn-cgi/trace
(or any site behind cloudflare’s proxy)
Result
You will get (if luckily enough) answer like:
fl=4f432
h=www.cloudflare.com
ip=fd01:5ca1:ab1e:8a3a:e30:ea85:e086:bb09
ts=1627899291.735
visit_scheme=https
uag=Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0
colo=SJC
http=http/3
loc=XX
tls=TLSv1.3
sni=plaintext
warp=off
gateway=off
Notice the fd01:5ca1:ab1e:8a3a:e30:ea85:e086:bb09
, it is a local address, and loc=XX
here.
Not only the address in trace, address recorded by my server (X-Forwarded-For
) shows the local address too, making applications relay on per ip rate limit/user region no longer work.
(Might be some bugs present when the http/3
traffic routes between cloudflare servers?)