What is X-Real-IP?

X-Real-IP is a commonly used non-standard header through which a proxy passes one representative candidate client IP. It is often set by nginx.

What can it tell you?

It normally contains one IP, but its meaning depends on proxy configuration. No universal standard automatically guarantees authenticity.

How NetKarte shows it

Read X-Real-IP under Forwarding headers in the HTTP information card. No input is needed: the received value appears automatically. NetKarte considers it as an IP candidate only within the managed reverse proxy's trust boundary, so displaying it is separate from selecting it.

Notes

It can be spoofed if clients may send the same header directly. The proxy should overwrite existing values and the application should accept it only over a trusted path.

How it differs from X-Forwarded-For

X-Forwarded-For can carry several stages; X-Real-IP usually carries one candidate. The word “Real” does not authenticate it. A proxy configured to use its immediate peer can put another intermediary's IP here.

Was it selected by NetKarte?

Read Source alongside the chosen IP in the top IP card of Network diagnostics. When forwarding information is trusted, NetKarte checks Forwarded, X-Forwarded-For, then X-Real-IP. A displayed X-Real-IP may therefore not be the selected value.

If headers disagree, an administrator should check whether they were configured to represent the same thing. Editing client headers until they match does not validate the network path.