Hi Jai, If your proxy supports the HTTP CONNECT method, you can try revising your settings to this: [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = wproxy.qut.edu.au:3128 protocolHost = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 protocol = connect Only the connect protocol supports using the protocolHost option. If this isn't supported by your proxy, you can try using Privoxy or Polipo between stunnel and your proxy. Socat is another option as well. Andrew Krause Schaumburg Township District Library -----Original Message----- At QUT Library we use Stunnel to encrypt SIP2 (ie. book borrowing) traffic from the self-checkout machines through to the Alma library services platform (as per https://developers.exlibrisgroup.com/alma/integrations/stunnel/ ) Our self-checkout machines run Windows 10 and are allowed limited internet access to two hosts (cloud.fetechgroup.com and ap01.alma.exlibrisgroup.com) via our institution's Squid proxy and I have our current WinHTTP proxy settings: Proxy Server(s) : wproxy.qut.edu.au:3128 Bypass List : *.qut.edu.au The proxy server settings are set for all protocols (HTTP, HTTPS, secure and FTP) and I've confirmed that web browser and the FE Technologies software is routing via wproxy.qut.edu.au. However Stunnel is still trying to connect to Alma directly. Our stunnel.conf is as follows (just FYI, the FE Tech software points to 127.0.0.1:5001 as our library services platform address): [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Is there a way to force Stunnel to either respect the WinHTTP settings or configure it to route traffic to wproxy.qut.edu.au:3128 before initiating the connect = hostname:port? I did try protocolHost as follows, but I'm probably misunderstanding how it works https://www.stunnel.org/static/stunnel.html#SERVICE-LEVEL-OPTIONS [KG_Self-Checkout] key = client.pem cert = client.pem client = yes accept = 127.0.0.1:5001 connect = wproxy.qut.edu.au:3128 protocolHost = ap01.alma.exlibrisgroup.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 sslVersion = TLSv1.2 Any advice or assistance gratefully accepted, and apologies if this is a silly question - I'm just a librarian trying to make this thing work. Thanks, Jai Parker | Information Access Librarian QUT Library | Division of Administrative Services QUT | Kelvin Grove | D Block, Level 1 | Victoria Park Rd Kelvin Grove QLD 4059 P: 07 3138 3381 | E: lib.infoaccess at qut.edu.au<mailto:lib.infoaccess at qut.edu.au> | www.qut.edu.au<http://www.qut.edu.au/> ABN: 83 791 724 622 | CRICOS No. 00213J