What determines the path packets take from source to destination?
In computer networks, source routing, also called path addressing, allows the sender of a packet to partially or fully specify the path the packet takes through the network. In contrast, in conventional routing, routers on the network incrementally determine the route based on the destination of the packet.
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What is the destination IP that the proxy sees in the request?
Direct HTTP requests: The destination IP is the HTTP server and the requested URI shows only the path behind the domain. HTTP proxy requests: The first packet is sent to the proxy. The Requested URI shows the full URL (host + path). The second packet is sent from the proxy to the final destination.
What is a proxy server and what does it do?
A proxy server provides a gateway between users and the Internet. It is a server, called an “intermediary” because it goes between end users and the web pages they visit online. When a computer connects to the Internet, it uses an IP address.
What is ProxyARP? How does it work?
Proxy ARP is a technique by which a proxy server on a given network responds to Address Resolution Protocol (ARP) queries for an IP address that is not on that network. Traffic addressed to the proxy address is usually routed by the proxy to the intended destination through another interface or through a tunnel.
Can we determine the network path that the packets take at the destination node?
No, that’s part of the charm of IP. The closest way to determine this, that I know of, would be to assume that the reverse path is the same as the direct path, and the destination node can do an ICMP “trace route” back to the source IP address.
Do packets always follow the same path?
Yes, in general, all packets in a TCP stream will follow the same path through the network; even in the presence of a “diamond” network, all packets in the same flow will be routed on the same side of the diamond.
Is proxy ARP a security risk?
Potential Security Risk Any device can be accessed by sending an ARP request. This can increase the amount of ARP traffic on your network. Also, it makes it more difficult to detect ARP spoofing, as an attacker can easily hide behind the MAC address of the router or switch.
What are the disadvantages of proxy ARP?
Proxy ARP Disadvantages
- Increases the amount of ARP traffic on your segment.
- Hosts need larger ARP tables to handle IP to MAC address mappings.
- Security can be undermined.
- It does not work for networks that do not use ARP for address resolution.
- It does not generalize to all network topologies.
How does OSPF determine the best route?
If there are multiple routes to a network with the same route type, the OSPF metric calculated as cost versus bandwidth is used to select the best route. The route with the lowest value for cost is chosen as the best route.
How are packets sent in a proxy request?
HTTP proxy requests: The first packet is sent to the proxy. The Requested URI shows the full URL (host + path). The second packet is sent from the proxy to the final destination. And since it’s a “real” proxy, both packets are also inside their own TCP connection with different source addresses.
How are packets delivered to the destination host?
To deliver the packet to the destination host, the source IP, destination IP, source MAC address, and destination MAC address must be known. Some basic rules for packet flow: If the destination host is present on the same network, then the packet is delivered directly to the destination host.
How does a proxy work when using HTTPS?
When HTTPS is used with a proxy, clients send a CONNECT request that identifies the destination host they want to connect to, and then perform TLS negotiation. However, proxy-unaware clients will proceed directly to the TLS negotiation, believing that they are communicating directly with the destination host.
How are HTTP proxy requests different from direct HTTP requests?
Direct HTTP requests: The destination IP is the HTTP server and the requested URI shows only the path behind the domain. The above is a DNS request from the client to your configured recursive DNS server. HTTP proxy requests: The first packet is sent to the proxy. The Requested URI shows the full URL (host + path).