Dynamic address allocation method, device and system thereof

Abstract

The invention discloses a dynamic address allocation method, a device and a system thereof, wherein, the method comprises the following steps: a PE receives a DHCP message from a VPN network via a VPN port; the PE adds a VPN export RT attribute to the DHCP message, alters a source IP address of the DHCP message to a public IP address of the PE, alters a destination IP address to a DHCP server address, and transmits the DHCP message to the DHCP server after filling in an IP address of a trunking gateway; the PE receives a response message from the DHCP server, selects a corresponding VPN according to the export RT attribute carried in the response message, and sends the IP address allocated by the DHCP server to a client side of the corresponding VPN. Various VPNs share one DHCP server to allocate addresses dynamically as the VPNs are located in one MPLS VPN network, which facilitates maintenance, saves investment, and relieves network planning and IP address planning from restriction.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a method, device and system for dynamic address allocation. Background technique [0002] With the continuous expansion of network scale and the improvement of network complexity, the number of clients (such as computers, etc.) in the network often exceeds the number of IP (Internet Protocol, Internet Protocol) addresses available for distribution; With the wide use of the network, the location of the computer in the network is often changed, and the corresponding IP address must be updated frequently, which makes the process of configuring the IP address on the network more and more complicated. DHCP (Dynamic Host Configuration Protocol, Dynamic Host Configuration Protocol) was developed to meet these requirements. [0003] DHCP adopts the client / server communication mode. The client submits a configuration request to the server, and the server returns correspond...

AI Technical Summary

Problems solved by technology

Since the Super-VPN needs to learn the routes of VPN1 and VPN2 at the same time, the addresses of VPN1 and VPN2 cannot overlap. At the same time, in order to ensure the security of information between VPN1 and VPN2, the networks of VPN1 and VPN2 cannot communicate through the Super-VPN, so it is necessary to Pay attention to avoid overlapping and intercommunication during networking. For example, if Super-VPN has a default route with the next hop of CE3 advertised to VPN1 and VPN2, since CE3 can learn all the routes of VPN1 and VPN2, then VPN1 and VPN2 VPN2 may communicate through CE3, resulting in reduced security between VPN1 and VPN2

[0008] Therefore, the shared VPN needs to learn the routes of each VPN, so that the addresses between the VPNs cannot overlap, and the address planning is restricted, which reduces the independence of the VPN. In addition, it is necessary to prevent each VPN from communicating through the shared VPN. Interconnection routes cannot exist in the devices connected to each VPN, and network deployment is more troublesome

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