Arp proxy Overview

Arp proxy Overview 1. Free arp: The difference between free ARP packets and normal arp request packets is that normal arp request packets. The "Destination IP address" In ARP encapsulation is the IP address of other machines, for free arp request packets, the "Destination IP address" In ARP encapsulation is its own IP address. Some Applications of free ARP in the actual environment: 1. Use free ARP to confirm the device interface address; 2. Use free ARP packets to update the ARP table items of some devices; 3, use free ARP attacks; 4. Use free ARP to prevent ARP attacks. Arp command 2 in linux: Delegate arp if an ARP request is sent from one network host to another, then the router connecting the two networks can answer the request, this process is called the delegate ARP or ARP proxy. In this way, the sender of the ARP request can be spoofed to assume that the vro is the destination host. In fact, the destination host is on the other end of the vro. The vro function is equivalent to the proxy of the destination host, forward the group from another host. In this case, a router with ARP proxy is required. ARP proxy is also known as promiscuous ARP or ARPhack ). These names come from ARP proxy for other purposes: routers between two physical networks can hide physical networks. In this case, the two physical networks can use the same network number, as long as the intermediate router is set as an ARP proxy to respond to ARP requests from one network to another. In the past, this technology was used to hide a group of hosts running earlier versions of TCP/IP on different physical cables. There are two common reasons for separating these old hosts. One is that they cannot process subnet division, and the other is that they use the old broadcast address (all the host numbers whose bits are 0, instead of the host number with the current bits of 1 ).