SYSTEM AND METHODS FOR MANAGING NETWORK PROTOCOL ADDRESS ASSIGNMENT WITH A CONTROLLER

• US 20130097335A1
• Filed: 10/14/2011
• Published: 04/18/2013
• Est. Priority Date: 10/14/2011
• Status: Active Grant

• Current Assignee: Arista Networks, Inc.
• Original Assignee: Big Switch Networks, Inc. (Arista Networks, Inc.)
• Inventors: Zhou, Shudong, Adams, Robert Edward, Dhami, Mandeep Singh, Reimers, Alexander Stafford David, Jiang, Kanzhe
• Granted Patent: US 8,856,384 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 61/2528 Translation at a proxy
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5061 Pools of addresses
• CPC Class Codes: H04L 61/5076 Update or notification mechanisms, e.g. DynDNS
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

A controller may help reduce network traffic that is associated with broadcasting of Dynamic Host Configuration Protocol (DHCP) packets by converting broadcast DHCP packets into unicast DHCP packets and forwarding the unicast DHCP packets to appropriate DHCP servers. The servers may be identified from a database of servers that is updated with DHCP server address information based on DHCP reply packets that are received by the controller from servers in the network. To convert DHCP request packets into unicast packets, the controller may modify address header fields of the packets such as Ethernet addresses and Internet Protocol (IP) addresses. The controller may forward the modified DHCP request packets to the server by providing packet forwarding rules such as flow table entries to the switches or by forwarding the modified DHCP request packets through the controller.

Claims

1. A method of using a controller to control switches in a network, the method comprising:

with the controller, identifying whether a network packet that is sent from an end host is requesting assignment of a protocol address to the end host;

in response to identifying that the network packet requests assignment of a protocol address to the end host, processing the network packet with the controller; and

with the controller, controlling the switches by providing at least one of the switches with the network packet that has been processed by the controller.

2. The method defined in claim 1 wherein identifying that the network packet is requesting assignment of a protocol address to the end host comprises:

retrieving information from packet header fields of the network packet.

3. The method defined in claim 1 wherein identifying that the network packet is requesting assignment of a protocol address to the end host comprises:

identifying that the network packet is a Dynamic Host Configuration Protocol request.

4. The method defined in claim 1 wherein processing the network packet with the controller comprises:

with the controller, identifying a server that has protocol address assignment capabilities; and

with the controller, forwarding the network packet to the server.

5. The method defined in claim 4 wherein identifying the server that has protocol address assignment capabilities comprises:

selecting a Dynamic Host Configuration Protocol server from a database.

6. The method defined in claim 4 wherein forwarding the network packet to the server comprises forwarding the network packet through the controller to a switch that is coupled to the server.

7. The method defined in claim 4 wherein forwarding the network packet to the server comprises providing packet forwarding rules to the switches that direct the switches to forward the network packet from the end host to the server.

8. The method defined in claim 4 wherein processing the network packet with the controller further comprises:

forming a modified packet by modifying at least one header field of the network packet, wherein forwarding the network packet to the server comprises forwarding the modified packet to the server.

9. The method defined in claim 8 wherein modifying at least one header field of the network packet comprises:

modifying at least one Ethernet address field of the network packet.

10. The method defined in claim 8 wherein modifying at least one header field of the network packet comprises:

modifying at least one Internet Protocol address field of the network packet.

11. The method defined in claim 8 wherein forming the modified packet comprises:

modifying a gateway Internet Protocol address field of the network packet.

12. The method defined in claim 4 further comprising:

with the controller, receiving a list of authorized servers from a network administrator;

with the controller, receiving a reply packet that corresponds to the network packet from the server;

with the controller, determining whether the server is authorized to send the reply packet to the end host based on the list of authorized servers;

in response to determining that the server is authorized to send the reply packet to the end host, forwarding the reply packet to the end host with the controller; and

in response to determining that the server is not authorized to send the reply packet to the end host, dropping the reply packet with the controller.

13. The method defined in claim 1 further comprising:

with the controller, receiving a Dynamic Host Configuration Protocol packet from a server;

with the controller, retrieving address information of the server from the Dynamic Host Configuration Protocol packet; and

storing the address information in a database, wherein processing the network packet with the controller comprises retrieving the address information from the database.

14. A method of using a controller to control network traffic through switches in a network, the method comprising:

with the controller, identifying whether a network packet sent from an end host is a Dynamic Host Configuration Protocol broadcast packet; and

in response to identifying that the network packet is a Dynamic Host Configuration Protocol broadcast packet, modifying the network packet with the controller.

15. The method defined in claim 14 wherein modifying the network packet comprises modifying a destination address field of the network packet.

16. The method defined in claim 15 further comprising:

retrieving address information of a Dynamic Host Configuration Protocol server from a database, wherein modifying the destination address field of the network packet comprises storing the address information of the Dynamic Host Configuration Protocol server in the destination address field.

17. A method of controlling traffic in a network of switches, the method comprising:

with the controller, receiving a Dynamic Host Configuration Protocol request packet that is sent from an end host; and

based on network topology information associated with the network of switches, modifying the Dynamic Host Configuration Protocol request packet with the controller.

18. The method defined in claim 17 wherein the network is partitioned into subnetworks associated with respective address ranges and wherein the end host is associated with a given subnetwork, the method further comprising:

with the controller, identifying a server for fulfillment of the Dynamic Host Configuration Protocol request packet;

with the controller, identifying whether the server is associated with the given subnetwork based on the network topology information;

in response to identifying that the server is associated with the given subnetwork, modifying an Ethernet address field of the Dynamic Host Configuration Protocol request packet; and

in response to identifying that the server is not associated with the given subnetwork, modifying an Internet Protocol address field of the Dynamic Host Configuration Protocol request packet.

19. The method defined in claim 18 wherein identifying whether the server is associated with the subnetwork comprises:

comparing an Internet Protocol address of the server to an address range of the given subnetwork.

20. The method defined in claim 18 wherein modifying the Internet Protocol address field of the Dynamic host Configuration Protocol request packet comprises:

modifying a gateway Internet Protocol address field of the Dynamic Host Configuration Protocol request packet.