Multicast trunking in a network device
View Patent ↗A network device for uniform distribution of non-unicast traffic, such as layer 2 broadcast, layer 2 multicast, unknown unicast and layer 3 multicast on a truch group. The network device includes at least one trunk group including a plurality of physical ports. The network device is connected to at least one other network device by a number of the plurality of physical ports. The network device also includes a table with a plurality of entries, wherein each entry is associated with the number of the plurality of physical ports on the network device. Each entry specifies if a packet should be transmitted on one of the plurality of physical ports. The network device further includes hashing means for hashing a predefined number of bits from predefined fields in the packet to select one entry in the table. The selected entry is used to identify a destination port. The network device also includes transmitting means for transmitting the packet to the destination port.
1. A network device for distribution of non-unicast traffic on a trunk group by selecting an appropriate port from the trunk group on which to transmit a non-unicast packet, the network device comprising:
at least one trunk group comprising a plurality of physical ports, wherein the network device is connected to at least one other network device by a number of the plurality of physical ports;
a table comprising a plurality of entries, wherein each entry is associated with the number of the plurality of physical ports on the network device and each entry specifies if a packet should be transmitted on one of the plurality of physical ports;
hashing means configured to hash a predefined number of bits from a source address, a destination address, and a source port trunk group identifier in the packet to obtain an index to select one entry in the table, wherein the selected entry is used to identify a destination port; and
transmitting means for transmitting the packet to the destination port.
2. The network device according to claim 1 , wherein the table is configured as a 16 entry table, wherein each entry comprises a field that is associated with one of the number of the plurality of physical ports.
3. The network device according to claim 1 , wherein the table is configured to set one field that is associated with one of the plurality of physical ports to allow the packet transmission.
4. The network device according to claim 1 , wherein the table is configured to set fields that are associated with the number of the plurality of physical ports to block the packet transmission.
5. The network device according to claim 1 , wherein the table is configured such that entries in the table are programmed in different way for the trunk group.
6. The network device according to claim 1 , wherein the hashing means is configured to hash, if the packet is one of a layer 2 broadcast, multicast or unknown unicast, the predefined number of bits from the source address, the destination address, source port and a source module identifier to obtain the index for accessing one entry in the table.
7. The network device according to claim 1 , wherein the hashing means is configured to hash, if the packet is an IP multicast, the predefined number of bits from a source IP address, a destination IP address and a source port trunk group identifier to obtain the index for accessing one entry in the table.
8. The network device according to claim 1 , wherein the hashing means is configured to hash, if the packet is an IP multicast, the predefined number of bits from a source IP address, a destination IP address, a source port and a source module identifier to obtain the index for accessing one entry in the table.
9. A method for uniform distribution of non-unicast traffic on a trunk group by selecting an appropriate port from the trunk group on which to transmit a non-unicast packet, the method comprising:
connecting the network device to at least one other network device by a number of a plurality of physical ports in at least one trunk group;
storing a plurality of entries in a table, wherein each entry is associated with the number of the plurality of physical ports;
specifying in each entry if a packet should be transmitted on one of the plurality of physical ports;
hashing a predefined number of bits from a source address, a destination address, and a source port trunk group identifier in the packet to obtain an index to select one entry in the table;
identifying a destination port by a selected entry; and
transmitting the packet to the destination port.
10. The method according to claim 9 , further comprising storing at least one field in each entry, wherein the at least one field is associated with one of the number of the plurality of physical ports.
11. The method according to claim 9 , further comprising setting one field that is associated with one of the plurality of physical ports to allow the packet transmission.
12. The method according to claim 9 , further comprising setting fields that are associated with the number of the plurality of physical ports to block the packet transmission.
13. The method according to claim 9 , further comprising programming entries in the table in different way for the trunk group.
14. The method according to claim 9 , wherein the hashing includes hashing, if the packet is one of a layer 2 broadcast, multicast or unknown unicast, the predefined number of bits from the source address, the destination address, source port and a source module identifier to obtain the index for accessing one entry in the table.
15. The method according to claim 9 , wherein the hashing includes hashing, if the packet is an IP multicast, a predefined number of bits from a source IP address, a destination IP address and a source port trunk group identifier to obtain the index for accessing one entry in the table.
16. The method according to claim 9 , wherein the hashing includes hashing, if the packet is an IP multicast, a predefined number of bits from a source IP address, a destination IP address, a source port and a source module identifier to obtain the index for accessing one entry in the table.
17. An apparatus for uniform distribution of non-unicast traffic on a trunk group by selecting an appropriate port from the trunk group on which to transmit a non-unicast packet, the apparatus comprising:
connecting means for connecting the network device to at least one other network device by a number of a plurality of physical ports in at least one trunk group;
storing means for storing a plurality of entries in a table, wherein each entry is associated with the number of the plurality of physical ports;
specifying means for specifying in each entry if a packet should be transmitted on one of the plurality of physical ports;
hashing means for hashing a predefined number of bits from a source address, a destination address, source port and a source port module identifier in the packet to obtain an index to select one entry in the table;
identifying means for identifying a destination port by a selected entry; and
transmitting means for transmitting the packet to the destination port.