MULTICAST TRAFFIC MANAGEMENT IN A NETWORK INTERFACE

• US 20110019673A1
• Filed: 12/17/2009
• Published: 01/27/2011
• Est. Priority Date: 07/27/2009
• Status: Active Grant

• Current Assignee: Media Patents S.L.
• Original Assignee: Media Patents S.L.
• Inventors: Fernández Gutiérrez, Alvaro
• Granted Patent: US 8,189,584 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06

Abstract

A method for filtering in a network interface of a computer system multicast packets in a manner that reduces or obviates altogether the processing of unwanted multicast packets by the processing unit of the computer system. Filtering in the network interface is accomplished by the network interface accessing multicast traffic request information originating in the computer system and comparing the accessed information with the multicast destination address and IP source address of packets received in the network interface.

Claims

1. A method of filtering multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the computer system having a first memory, the method comprising:

storing for the network interface and a multicast group address information in the first memory for the purpose of enabling or disabling transmission through the network interface to the bus of the computer system multicast packets sent from sources using the multicast group address, the information comprising first data that identifies the network interface, second data that identifies the multicast group address, third data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and fourth data that identifies a source-list of zero or more IP source addresses,

the network interface accessing the second, third and fourth data,

receiving in the network interface a multicast packet from the multicast data network,

determining in the network interface the multicast group address and IP source address of the multicast packet,

determining in the network interface if transmission of the multicast packet from the network interface to the bus is to be enabled or disabled by comparing the multicast group address and the IP source address of the multicast packet with the accessed second, third and fourth data; and

upon determining that the transmission of the multicast packet is to be enabled, the network interface transmitting the multicast packet to the bus, or upon determining that the transmission of the multicast packet is to be disabled, the network interface not transmitting the multicast packet to the bus.

2. A method according to claim 1, wherein accessing of the second, third and fourth data by the network interface is accomplished by the network interface reading the second, third and fourth data from the first memory.

3. A method according to claim 2, wherein the network interface uses direct memory access (DMA) to read the second, third and fourth data from the first memory.

4. A method according to claim 1, wherein accessing of the second, third and fourth data by the network interface is accomplished by the network interface copying the second, third and fourth data from the first memory into a second memory of the network interface.

5. A method according to claim 1, wherein accessing of the second, third and fourth data by the network interface is accomplished by the computer system sending from the first memory the second, third and fourth data to the network interface for storage in a second memory of the network interface.

6. A method according to claim 5, wherein a driver installed on the computer system sends from the first memory the second, third and fourth data to the network interface.

7. A method according to claim 1, wherein the storing of the information in the first memory is accomplished by an IPMulticastListen operation.

8. A method according to claim 1, wherein the accessing of the second, third and fourth data by the network interface is accomplished by an IPMulticastListen operation in the computer system that sends the second, third and fourth data to the network interface for storage in a second memory of the network interface.

9. A method according to claim 1, wherein the storing of the information in the first memory is accomplished by an IPMulticastListen operation writing the first, second, third and fourth data into the first memory and wherein the accessing of the second, third and fourth data by the network interface is accomplished by the IPMulticastListen operation sending the second, third and fourth data to the network interface for storage in a second memory of the network interface.

10. A method according to claim 9, wherein the IPMulticastListen operation writes the first, second, third and fourth data to the first memory and sends the second, third and fourth data to the network interface substantially simultaneously.

11. A method according to claim 1, wherein the first, second, third and fourth data are stored as a first state record in the first memory, the first state record having the form (interface, multicast-address, filter-mode, {source-list}).

12. A method according to claim 4, wherein the second, third and fourth data are stored as a second state record in the second memory, the second state record having the form (multicast-address, filter-mode, {source-list}).

13. A method according to claim 5, wherein the second, third and fourth data are stored as a second state record in the second memory, the second state record having the form (multicast-address, filter-mode, {source-list}).

14. A method according to claim 8, wherein the second, third and fourth data are stored as a second state record in the second memory, the second state record having the form (multicast-address, filter-mode, {source-list}).

15. A method according to claim 1, wherein the network interface always transmits to the bus first selected multicast packets irregardless of the accessed second, third and fourth data.

16. A method according to claim 15, wherein the first selected multicast packets are those having an All Hosts Multicast Address.

17. A method according to claim 15, wherein the first selected multicast packets are those having an all hosts link-scope address.

18. A method according to claim 15, wherein a user application in an operating system of the computer system is used to select the first selected multicast packets.

19. A method according to claim 1, wherein the network interface never transmits to the bus second selected multicast packets irregardless of the accessed second, third and fourth data.

20. A method according to claim 19, wherein a user application in an operating system of the computer system is used to select the second selected multicast packets.

21. A method according to claim 15, wherein a first record identifying the first selected multicast packets is stored in a second memory of the network interface, the first record having the form (multicast-address, filter-mode, {source-list}).

22. A method according to claim 19, wherein a second record identifying the second selected packets is stored in a second memory of the network interface, the second record having the form (multicast-address, filter-mode, {source-list}).

23. A method according to claim 15, wherein the network interface is configured to always transmits to the bus the first selected multicast packets by use of the Simple Network Management Protocol (SNMP).

24. A method according to claim 19, wherein the network interface is configured to never transmits to the bus the second selected multicast packets by use of the Simple Network Management Protocol (SNMP).

25. A method according to claim 1, wherein the filtering of multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

26. A method according to claim 1, wherein the network interface is integrated within a chipset of the computer system.

27. A method according to claim 1, wherein the network interface determines the multicast group address and IP source address of the multicast packet by reading an IP header of an IP packet encapsulated in the multicast packet.

28. A method of filtering multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface accessing, via the bus, information in the computer system for the purpose of enabling or disabling transmission through the network interface to the bus of the computer system multicast packets sent from sources in the multicast data network, the information comprising first data that identifies a multicast group address, second data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and third data that identifies a source-list of zero or more IP source addresses,

receiving in the network interface a multicast packet from the multicast data network,

determining in the network interface the multicast group address and IP source address of the multicast packet,

determining in the network interface if transmission of the multicast packet from the network interface to the bus is to be enabled or disabled by comparing the multicast group address and the IP source address of the multicast packet with the accessed first, second, and third data; and

upon determining that the transmission of the multicast packet is to be enabled, the network interface transmitting the multicast packet to the bus, or upon determining that the transmission of the multicast packet is to be disabled, the network interface not transmitting the multicast packet to the bus.

29. A method according to claim 28, wherein accessing of the first, second and third data by the network interface is accomplished by the network interface reading the first, second and third data from a first memory of the computer system.

30. A method according to claim 29, wherein the network interface uses direct memory access (DMA) to read the first, second and third data from the first memory.

31. A method according to claim 28, wherein accessing of the first, second and third data by the network interface is accomplished by the network interface copying the first, second and third data from a first memory of the computer system into a second memory of the network interface.

32. A method according to claim 29, wherein accessing of the first, second and third data by the network interface is accomplished by the computer system sending from a first memory of the computer system the first, second and third data to the network interface for storage in a second memory of the network interface.

33. A method according to claim 32, wherein a driver installed on the computer system sends from the first memory the first, second and third data to the network interface.

34. A method according to claim 31, wherein the first, second and third data are stored as a state record in the second memory, the state record having the form (multicast-address, filter-mode, {source-list}).

35. A method according to claim 32, wherein the first, second and third data are stored as a state record in the second memory, the state record having the form (multicast-address, filter-mode, {source-list}).

36. A method according to claim 28, wherein the network interface always transmits to the bus first selected multicast packets irregardless of the accessed first, second and third data.

37. A method according to claim 36, wherein the first selected multicast packets are those having an All Hosts Multicast Address.

38. A method according to claim 36, wherein the first selected multicast packets are those having an all hosts link-scope address.

39. A method according to claim 36, wherein a user application in an operating system of the computer system is used to select the first selected multicast packets.

40. A method according to claim 28, wherein the network interface never transmits to the bus second selected multicast packets irregardless of the accessed first, second and third data.

41. A method according to claim 36, wherein a user application in an operating system of the computer system is used to select the second selected multicast packets.

42. A method according to claim 36, wherein a first record identifying the first selected multicast packets is stored in a memory of the network interface, the first record having the form (multicast-address, filter-mode, {source-list}).

43. A method according to claim 40, wherein a second record identifying the second selected multicast packets is stored in a memory of the network interface, the second record having the form (multicast-address, filter-mode, {source-list}).

44. A method according to claim 36, wherein the network interface is configured to always transmits to the bus the first selected multicast packets by use of the Simple Network Management Protocol (SNMP).

45. A method according to claim 40, wherein the network interface is configured to never transmits to the bus the second selected multicast packets by use of the Simple Network Management Protocol (SNMP).

46. A method according to claim 28, wherein the filtering of multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

47. A method according to claim 28, wherein the network interface is integrated within a chipset of the computer system.

48. A method according to claim 28, wherein the network interface determines the multicast group address and IP source address of the multicast packet by reading an IP header of an IP packet encapsulated in the multicast packet.

49. A method of filtering IP multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface storing information for the purpose of enabling or disabling the transmission of IP multicast packets from sources in the multicast data network through the network interface to the bus of the computer system, the information comprising first data that identifies an IP multicast group address, second data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and third data that identifies a source-list of zero or more IP source addresses,

receiving in the network interface an IP multicast packet from the multicast data network,

determining in the network interface the IP multicast group address and the IP source address of the IP multicast packet,

determining in the network interface if transmission of the IP multicast packet from the network interface to the bus is to be enabled or disabled by comparing the IP multicast group address and the IP source address of the IP multicast packet with the first, second and third data; and

upon determining that the transmission of the IP multicast packet is to be enabled, the network interface transmitting the IP multicast packet to the bus, or upon determining that the transmission of the IP multicast packet is to be disabled, the network interface not transmitting the IP multicast packet to the bus.

50. A method according to claim 49, wherein the first, second and third data are stored as a state record, the state record having the form (multicast-address, filter-mode, {source-list}).

51. A method according to claim 49, wherein the network interface always transmits to the bus first selected IP multicast packets irregardless of the stored first, second and third data.

52. A method according to claim 51, wherein the first selected IP multicast packets are those having an All Hosts Multicast Address.

53. A method according to claim 51, wherein the first selected IP multicast packets are those having an all hosts link-scope address.

54. A method according to claim 49, wherein the network interface never transmits to the bus second selected IP multicast packets irregardless of the stored first, second and third data.

55. A method according to claim 51, wherein a first record identifying the first selected IP multicast packets is stored in the network interface, the first record having the form (multicast-address, filter-mode, {source-list}).

56. A method according to claim 54, wherein a second record identifying the second selected IP multicast packets is stored in the network interface, the second record having the form (multicast-address, filter-mode, {source-list}).

57. A method according to claim 51, wherein the network interface is configured to always transmits to the bus the first selected IP multicast packets by use of the Simple Network Management Protocol (SNMP).

58. A method according to claim 54, wherein the network interface is configured to never transmits to the bus the second selected IP multicast packets by use of the Simple Network Management Protocol (SNMP).

59. A method according to claim 49, wherein the filtering of IP multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

60. A method of filtering multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the computer system having a first memory, the network interface having a second memory, the method comprising:

an application of the computer system initiating a request for the purpose of enabling or disabling reception of multicast packets from the multicast data network, the request comprising first data that identifies the network interface, second data that identifies a multicast group address to which the request pertains, third data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and fourth data that identifies a source-list of zero or more IP source addresses,

storing the first, second, third and fourth data in the first memory,

the network interface accessing the second, third and fourth data,

receiving in the network interface a multicast packet from the multicast data network,

determining in the network interface the multicast group address and IP source address of the multicast packet,

determining in the network interface if reception of the multicast packet is to be enabled or disabled by comparing the multicast group address and the IP source address of the multicast packet with the second, third and fourth data stored in the second memory; and

upon determining that the reception of the multicast packet is to be enabled, the network interface transmits the multicast packet to the bus, or upon determining that the reception of the multicast packet is to be disabled, the network interface not transmitting the multicast packet to the bus.

61. A method according to claim 60, wherein accessing of the second, third and fourth data by the network interface is accomplished by the network interface reading the second, third and fourth data from the first memory.

62. A method according to claim 61, wherein the network interface uses direct memory access (DMA) to read the second, third and fourth data from the first memory.

63. A method according to claim 60, wherein accessing of the second, third and fourth data by the network interface is accomplished by the network interface copying the second, third and fourth data from the first memory into a second memory of the network interface.

64. A method according to claim 60, wherein accessing of the second, third and fourth data by the network interface is accomplished by the computer system sending from the first memory the second, third and fourth data to the network interface for storage in a second memory of the network interface.

65. A method according to claim 64, wherein a driver installed on the computer system sends from the first memory the second, third and fourth data to the network interface.

66. A method according to claim 60, wherein the storing of the information in the first memory is accomplished by an IPMulticastListen operation.

67. A method according to claim 60, wherein the accessing of the second, third and fourth data by the network interface is accomplished by an IPMulticastListen operation in the computer system that sends the second, third and fourth data to the network interface for storage in a second memory of the network interface.

68. A method according to claim 60, wherein the storing of the information in the first memory is accomplished by an IPMulticastListen operation writing the first, second, third and fourth data into the first memory and wherein the accessing of the second, third and fourth data by the network interface is accomplished by the IPMulticastListen operation sending the second, third and fourth data to the network interface for storage in a second memory of the network interface.

69. A method according to claim 68, wherein the IPMulticastListen operation writes the first, second, third and fourth data to the first memory and sends the second, third and fourth data to the network interface substantially simultaneously.

70. A method according to claim 60, wherein the first, second, third and fourth data are stored as a first state record in the first memory, the first state record having the form (interface, multicast-address, filter-mode, {source-list}).

71. A method according to claim 63, wherein the second, third and fourth data are stored as a second state record in the second memory, the second state record having the form (multicast-address, filter-mode, {source-list}).

72. A method according to claim 64, wherein the second, third and fourth data are stored as a second state record in the second memory, the second state record having the form (multicast-address, filter-mode, {source-list}).

73. A method according to claim 60, wherein the network interface always transmits to the bus first selected multicast packets irregardless of the accessed second, third and fourth data.

74. A method according to claim 73, wherein the first selected multicast packets are those having an All Hosts Multicast Address.

75. A method according to claim 73, wherein the first selected multicast packets are those having an all hosts link-scope address.

76. A method according to claim 73, wherein a user application in an operating system of the computer system is used to select the first selected multicast packets.

77. A method according to claim 60, wherein the network interface never transmits to the bus second selected multicast packets irregardless of the accessed second, third and fourth data.

78. A method according to claim 77, wherein a user application in an operating system of the computer system is used to select the second selected multicast packets.

79. A method according to claim 73, wherein a first record identifying the first selected packets is stored in a second memory of the network interface, the first record having the form (multicast-address, filter-mode, {source-list}).

80. A method according to claim 77, wherein a second record identifying the second selected packets is stored in a second memory of the network interface, the second record having the form (multicast-address, filter-mode, {source-list}).

81. A method according to claim 73, wherein the network interface is configured to always transmits to the bus the first selected multicast packets by use of the Simple Network Management Protocol (SNMP).

82. A method according to claim 77, wherein the network interface is configured to never transmits to the bus the second selected multicast packets by use of the Simple Network Management Protocol (SNMP).

83. A method according to claim 60, wherein the filtering of multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

84. A method of filtering IP multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface storing first information for the purpose of enabling or disabling the transmission of IP multicast packets from the multicast data network through the network interface to the bus of the computer system, the first information comprising first data that identifies an IP multicast group address, second data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and third data that identifies a source-list of zero or more IP source addresses,

the network interface storing second information for the purpose of always enabling the transmission of selected IP multicast packets from the multicast data network through the network interface to the bus of the computer system, the second information comprising fourth data that identifies an IP multicast group address, fifth data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and sixth data that identifies a source-list of zero or more IP source addresses,

receiving in the network interface an IP multicast packet from the multicast data network,

determining in the network interface the IP multicast group address and the IP source address of the IP multicast packet,

if a filtering conflict exists between the first information and the second information stored in the network interface, selecting either the first information or the second information for use in determining whether to enable or disable transmission of the IP multicast packet to the bus,

determining in the network interface if transmission of the IP multicast packet from the network interface to the bus is to be enabled or disabled by

     1) comparing the IP multicast group address and the IP source address of the IP multicast packet with the first, second and third data if no conflict exists between the first information and the second information or if the first information is selected for use in determining whether to enable or disable transmission of the IP multicast packet to the bus when a conflict exists between the first information and the second information, or

     2) comparing the IP multicast group address and the IP source address of the IP multicast packet with the fourth, fifth and sixth data if the second information is selected for use in determining whether to enable or disable transmission of the IP multicast packet to the bus when a conflict exists between the first information and the second information; and

upon determining that the transmission of the IP multicast packet is to be enabled, the network interface transmitting the IP multicast packet to the bus, or upon determining that the transmission of the IP multicast packet is to be disabled, the network interface not transmitting the IP multicast packet to the bus.

85. A method of filtering IP multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface storing first information for the purpose of enabling or disabling the transmission of IP multicast packets from the multicast data network through the network interface to the bus of the computer system, the first information comprising first data that identifies an IP multicast group address, second data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and third data that identifies a source-list of zero or more IP source addresses,

the network interface storing second information for the purpose of always disabling the transmission of selected IP multicast packets from the multicast data network through the network interface to the bus of the computer system, the second information comprising fourth data that identifies an IP multicast group address, fifth data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and sixth data that identifies a source-list of zero or more IP source addresses,

receiving in the network interface an IP multicast packet from the multicast data network,

determining in the network interface the IP multicast group address and the IP source address of the IP multicast packet,

if a filtering conflict exists between the first information and the second information stored in the network interface, selecting either the first information or the second information for use in determining whether to enable or disable transmission of the IP multicast packet to the bus,

determining in the network interface if transmission of the IP multicast packet from the network interface to the bus is to be enabled or disabled by

     1) comparing the IP multicast group address and the IP source address of the IP multicast packet with the first, second and third data if no conflict exists between the first information and the second information or if the first information is selected for use in determining whether to enable or disable transmission of the IP multicast packet to the bus when a conflict exists between the first information and the second information, or

     2) comparing the IP multicast group address and the IP source address of the IP multicast packet with the fourth, fifth and sixth data if the second information is selected for use in determining whether to enable or disable transmission of the IP multicast packet to the bus when a conflict exists between the first information and the second information; and

upon determining that the transmission of the IP multicast packet is to be enabled, the network interface transmitting the IP multicast packet to the bus, or upon determining that the transmission of the IP multicast packet is to be disabled, the network interface not transmitting the IP multicast packet to the bus.

86. A method of filtering multicast data packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface storing information for the purpose of enabling or disabling the transmission of multicast packets from sources in the multicast data network through the network interface to the bus of the computer system, the information comprising first data that identifies a layer 2 multicast destination address and second data that identifies a layer 2 source address,

receiving in the network interface a multicast packet,

determining in the network interface the layer 2 destination address and the layer 2 source address of the multicast data packet,

determining in the network interface if transmission of the multicast packet from the network interface to the bus is to be enabled or disabled by comparing the layer 2 destination address and the layer 2 source address of the multicast packet with the first and second data; and

upon determining that the transmission of the multicast packet is to be enabled, the network interface transmitting the multicast packet to the bus, or upon determining that the transmission of the multicast packet is to be disabled, the network interface not transmitting the multicast packet to the bus.

87. A method according to claim 86, wherein the multicast data network is an Ethernet network and the layer 2 destination address is a destination MAC address and the layer 2 source address is a Source MAC address.

88. A method according to claim 86, wherein the network interface always transmits to the bus multicast packets having a first selected layer 2 destination address irregardless of the stored first and second data.

89. A method according to claim 88, wherein a user application in an operating system of the computer system is used to select the first selected layer 2 destination address.

90. A method according to claim 86, wherein the network interface never transmits to the bus multicast packets having a second selected layer 2 destination address irregardless of the stored first and second data.

91. A method according to claim 90, wherein a user application in an operating system of the computer system is used to select the second selected layer 2 destination address.

92. A method according to claim 88, wherein the network interface is configured to always transmits to the bus multicast packets having the first selected layer 2 destination address by use of the Simple Network Management Protocol (SNMP).

93. A method according to claim 90, wherein the network interface is configured to never transmits to the bus multicast packets having the second selected layer 2 destination address by use of the Simple Network Management Protocol (SNMP).

94. A method according to claim 86, wherein the filtering of multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

95. A method of filtering multicast data packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the network interface storing information for the purpose of enabling or disabling the transmission of multicast packets from sources in the multicast data network through the network interface to the bus of the computer system, the information comprising first data that identifies a layer 2 multicast destination address and second data that identifies a layer 2 source address,

receiving in the network interface a data packet,

determining in the network interface if the data packet is a multicast packet,

if upon determining the data packet is not a multicast packet, the network interface transmits the data packet to the bus,

if upon determining the data packet is a multicast packet, the network interface determines the layer 2 destination address and the layer 2 source address of the multicast packet,

determining in the network interface if transmission of the multicast packet from the network interface to the bus is to be enabled or disabled by comparing the layer 2 destination address and the layer 2 source address of the multicast packet with the first and second data; and

upon determining that the transmission of the multicast packet is to be enabled, the network interface transmitting the multicast packet to the bus, or upon determining that the transmission of the multicast packet is to be disabled, the network interface not transmitting the multicast packet to the bus.

96. A method according to claim 95, wherein the network interface determines the data packet to be a multicast packet if the data packet has a layer 2 multicast destination address.

97. A method according to claim 95, wherein the network interface determines the data packet not to be a multicast packet if the data packet does not have a layer 2 multicast destination address.

98. A method according to claim 95, wherein the multicast data network is an Ethernet network and the layer 2 destination address is a destination MAC address and the layer 2 source address is a source MAC address.

99. A method according to claim 95, wherein the network interface always transmits to the bus multicast packets having a first selected layer 2 destination address irregardless of the stored first and second data.

100. A method according to claim 99, wherein a user application in an operating system of the computer system is used to select the first selected layer 2 destination address.

101. A method according to claim 95, wherein the network interface never transmits to the bus multicast packets having a second selected layer 2 destination address irregardless of the stored first and second data.

102. A method according to claim 101, wherein a user application in an operating system of the computer system is used to select the second selected layer 2 destination address.

103. A method according to claim 99, wherein the network interface is configured to always transmits to the bus multicast packets having the first selected layer 2 destination address by use of the Simple Network Management Protocol (SNMP).

104. A method according to claim 101, wherein the network interface is configured to never transmits to the bus multicast packets having the second selected layer 2 destination address by use of the Simple Network Management Protocol (SNMP).

105. A method according to claim 95, wherein the filtering of multicast packets in the network interface is enabled or disabled by the use of a user application of an operating system of the computer system.

106. A method of filtering IP multicast packets in a network interface situated between and coupled to a multicast data network and a bus of a computer system, the method comprising:

the computer system requesting to receive IP multicast packets from sources of a multicast group address in the multicast data network by sending through the network interface to equipment in the data network a first membership message, the first membership message comprising first data that identifies a multicast group address, second data that denotes an INCLUDE filter-mode, an EXCLUDE filter-mode, a change to INCLUDE mode, or a change to EXCLUDE mode, and third data that identifies a source-list of zero or more IP source addresses,

the network interface reading the first, second and third data in the membership message and storing a state record in a memory of the network interface information derived from the first, second and third data that comprises fourth data that identifies the multicast group address, fifth data that denotes an INCLUDE filter-mode or an EXCLUDE filter-mode, and sixth data that identifies a source-list of zero or more IP source addresses, the third, fourth and fifth data being stored in the memory of the network interface for the purpose of being used by the network interface to enable or disable the transmission of IP multicast packets from the multicast data network through the network interface to the bus of the computer system,

receiving in the network interface an IP multicast packet from the multicast data network,

determining in the network interface the IP multicast group address and the IP source address of the IP multicast packet,

determining in the network interface if transmission of the IP multicast packet from the network interface to the bus is to be enabled or disabled by comparing the IP multicast group address and the IP source address of the IP multicast packet with the fourth, fifth and sixth data; and

upon determining that the transmission of the IP multicast packet is to be enabled, the network interface transmitting the IP multicast packet to the bus, or upon determining that the transmission of the IP multicast packet is to be disabled, the network interface not transmitting the IP multicast packet to the bus.

107. A method according to claim 106, wherein the network interface maintains a timer for each IP source address in the source-list, the timer being used to manage the duration of each IP source address stored in the memory of the network interface.

108. A method according to claim 106, wherein the network interface maintains a group timer when the state record comprises an EXCLUDE mode, the group timer being used to manage the duration of the EXCLUDE mode.

109. A method according to claim 107, wherein when the state record comprises an INCLUDE mode, the state record has the following format:

(multicast address, INCLUDE, {source-list and source timers}).

110. A method according to claim 108, wherein when the state record comprises an EXCLUDE mode, the state record has the following format:

(multicast address, group timer, EXCLUDE, {source-list and source timers}).

111. A method according to claim 106, wherein the network interface maintains a source timer for each IP source address in the source-list, the source timers being used to manage the duration of each IP source address stored in the memory of the network interface, the network interface also maintaining a group timer when the state record comprises an EXCLUDE mode, the group timer being used to manage the duration of the EXCLUDE mode.

112. A method according to claim 111, wherein when the state record comprises an INCLUDE mode the state record is stored in the memory of the network interface in the following format:

(multicast address, INCLUDE, {source-list and source timers}) and wherein when the state record comprises an EXCLUDE mode the state record is stored in the memory of the network interface in the following format;

(multicast address, group timer, EXCLUDE, {source-list and source timers}).

113. A method according to claim 106, wherein upon receiving a second membership message for a multicast group address from the computer system that is of the type IS_IN, IS_EX, ALLOW, BLOCK, TO_IN or TO_EX, the network interface updates the state record from a State 1 to a State 2 and implements the actions according to one of the processes of Tables 5 or 6.

114. A method according to claim 111, wherein upon receiving a second membership message for a multicast group address from the computer system that is of the type IS_IN, IS_EX, ALLOW, BLOCK, TO_IN or TO_EX, the network interface updates the state record from a State 1 to a State 2 and implements the actions according to one of the processes of Tables 2, 3 or 4.

115. A method according to claim 106, wherein the computer system only uses the IGMPv3 protocol, the network interface reading only membership messages having a destination address of 224.0.0.22.

116. A method according to claim 106, wherein the computer system only uses the MLDv2 protocol, the network interface reading only membership messages having a destination address of FF02:

;

16.