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Apologies for these silly questions. As I am new to networking. For example, If I configured my browser to use proxy of IP address: a.b.c.d and my IP address: e.f.g.h. And I visit example.com. What does my packet contain to instruct the proxy server to forward to example.com? Do the packet contains multiple headers such as one with source IP: e.f.g.h and dest IP: a.b.c.d and another with source IP: e.f.g.h and dest IP: example.com?

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  • The HTTP header contents depend on the proxy and its configuration. The IP packet just contains the proxy's public IP address as source. Proxies, application-layer protocols and networks not under your control are all off-topic here, however. – Zac67 Jul 21 '20 at 6:19
  • ... and there can only be one header in an IP packet (unless tunneling is involved which is something entirely different). – Zac67 Jul 21 '20 at 7:53
  • Sadly, questions about application protocols like http are off topic here. You can try asking this question on Super User. – Ron Trunk Jul 21 '20 at 11:52
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When proxy is handling internet traffic in networks .proxy acts as gateway between your LAN and internet . It is a device or server act as a intermediate device to serve all outbound internet traffic initial from LAN. Even we can control traffic using proxy like web filtering, traffic shaping etc ,

Traffic flow

When traffic is initiated from browser. With destination domain example .com a packet is created with L2 and L3 Header with source IP as desktop IP and destination IP example.com domain resolved public IP this entire packet is enclosed with another header as source IP as desktop IP destination IP as proxy IP which is mentioned in browser settings this enclosed packet will reach proxy . Now proxy will reset this connection and this session will be in mute state proxy will remove enclosed header and initiates new session with source as proxy IP and destination as examples .com domain resolved public IP. Once response is received from destination. proxy will again unmute session forward same response traffic to source desktop

So in this process proxy will initiates new session from proxy to destination...

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    Your description of a proxy is completely wrong. What you're describing really is a tunneled connection. With an HTTP proxy, the client creates a TCP connection to the proxy and only passes the destination host/URL in the HTTP header. There is no double encapsulation. See RFC 2068 for details. – Zac67 Jul 24 '20 at 15:35
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    i am just explaining users about traffic flow of traffic when internet hosted websites are accessed from LAN network where as proxy is acting as intermediate device for handling traffic – Sagar Uragonda Jul 24 '20 at 16:26
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    You're explaining something else, not HTTP via proxy. Do read the RFC. – Zac67 Jul 24 '20 at 18:01

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