Method and system for realizing proxy arp function based on dhcp listening

Abstract

The invention discloses a method and a system for realizing a proxy ARP (Address Resolution Protocol) function based on DHCP (Dynamic Host Configuration Protocol) interception. The method comprises the following steps that: a DHCP interception function is started up in an access layer switch, the proxy ARP function is started up in an aggregation layer switch, and the IP (Internet Protocol) address of the aggregation layer switch is configured in the access layer switch; the access layer switch intercepts a DHCP requesting process of a client-side, creates and stores binding information, and uploads the binding information to the aggregation layer switch; the aggregation layer switch stores the binding information into a binding information table; and the client-side sends an ARP requesting message to the aggregation layer switch, and the aggregation layer switch queries the binding information table, and sends an ARP response message to the client-side when the binding information table contains the destination IP address of the ARP requesting message. With the adoption of the technical scheme provided by the invention, the accessibility in the detection of the destination IP address by using proxy ARP equipment can be achieved, so that the communication between a requesting terminal and a destination terminal is ensured.

Description

technical field [0001] The invention relates to the field of computer data communication, in particular to a method and system for realizing proxy ARP function based on DHCP snooping. Background technique [0002] Dynamic Host Configuration Protocol (DHCP) is a LAN network protocol, using UDP protocol to work, mainly for two purposes: to automatically assign IP addresses to users for internal networks or network service providers to internal network administrators as A means of centrally managing all computers. [0003] The DHCP snooping (SNOOPING) function refers to the process that the switch monitors the DHCP client to obtain an IP address through the DHCP protocol. It prevents DHCP attacks and privately sets up DHCP servers by setting trusted ports and untrusted ports. DHCP messages received from trusted ports can be forwarded without verification. A typical setup is to connect trusted ports to a DHCP server or DHCP relay agent. When an untrusted port is connected to...

AI Technical Summary

Problems solved by technology

[0006] The defect of proxy ARP is that the device does not detect the reachability of the target IP and directly sends an ARP response to the requesting end. If there is a mapping relationship between the IP of the target host and the hardware address in the ARP cache of the requesting end, the requesting terminal will think that the destination terminal exists. , but in fact the situation where the intercommunication is not possible

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