Did you try this *curl -H "Host: httbin.org:443 <https://urldefense.proofpoint.com/v2/url?u=http-3A__httbin.org-3A443&d=DwMFaQ&c=sWW_bEwW_mLyN3Kx2v57Q8e-CRbmiT9yOhqES_g_wVY&r=5nE_8e-Jc1t5vF6GVeub9BCN4FzSc_6kU7_mjSiUrDs&m=KGt-kuF-04DSoLQysb_TMJDLA4T9KCKYMuLArHdTLas&s=MBLXeQRLg_U6jGJDITRJv1XDNrdcKUXXNLdoJw747QE&e=>" https://127.0.0.1:8443 <https://urldefense.proofpoint.com/v2/url?u=http-3A__127.0.0.1-3A8443&d=DwMFaQ&c=sWW_bEwW_mLyN3Kx2v57Q8e-CRbmiT9yOhqES_g_wVY&r=5nE_8e-Jc1t5vF6GVeub9BCN4FzSc_6kU7_mjSiUrDs&m=KGt-kuF-04DSoLQysb_TMJDLA4T9KCKYMuLArHdTLas&s=KOw_NDzToZ5m9aOAknPwadHs8jMEx_YKDAWaT5kKRX4&e=> -vv*
Note the "https" for the URL. If you don't use "--proxy" and the URL is "http", then curl will not attempt to use TLS during the connection. Alternatively, note Susan's suggestion - curl -k -v --resolve 'httbin.org:4443:127.0.0.1' https://httpbin.org:4443/get?answer=4a <https://urldefense.proofpoint.com/v2/url?u=https-3A__httpbin.org-3A4443_get-3Fanswer-3D4a&d=DwMFaQ&c=sWW_bEwW_mLyN3Kx2v57Q8e-CRbmiT9yOhqES_g_wVY&r=5nE_8e-Jc1t5vF6GVeub9BCN4FzSc_6kU7_mjSiUrDs&m=CJRs6tsuoI10rfl5-7BXCVEZV1qNbJIXaf3CblZVIjU&s=_9FxWsURWRJuQDxVN0_htTFCut7inhRRStAJHtgPEbA&e=> What you actually did was curl -k -v --resolve 'httbin.org:8443:127.0.0.1' https://httpbin.org/get?answer=42 <https://urldefense.proofpoint.com/v2/url?u=https-3A__httpbin.org_get-3Fanswer-3D42&d=DwMFaQ&c=sWW_bEwW_mLyN3Kx2v57Q8e-CRbmiT9yOhqES_g_wVY&r=5nE_8e-Jc1t5vF6GVeub9BCN4FzSc_6kU7_mjSiUrDs&m=GCeGAsAuMOtYawkiZoW91LT001Dp0_yEVsYttQWDsac&s=pygV3JDTpp005eNPhaNU8vn3U6hWMBTvZl-sIpm82OI&e=> -v These are not the same.
