Unicast trunking in a network device

Abstract

A network device for selecting a port from a trunk group to transmit a unicast packet on the selected port. The network device includes at least one trunk group including a plurality of physical ports. The network device also includes a table with a plurality of entries. Each entry is associated with one trunk group and includes a plurality of fields that are associated with ports in the trunk group. Each entry also includes a hash field that is used to select bits from predefined fields of an incoming unicast packet to obtain an index bit for accessing one of the plurality of fields. The network device further includes transmitting means for transmitting the unicast packet to a port associated with an accessed one of the plurality of fields.

1 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a source address, a VLAN, an Ethertype, a source module identifier and a source port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       2 . The network device according to  claim 1 , wherein the table is configured as a 128 entry table, wherein each entry comprises fields for eight ports. 
   
   
       3 . The network device according to  claim 1 , wherein each of the plurality of fields are configured to include an identifier for the network device and an identifier for one of the plurality of ports. 
   
   
       4 . The network device according to  claim 1 , wherein if the network device comprises less than eight ports, the table is configured to store redundant information from at least one of the plurality of fields in at least another one of the plurality of fields. 
   
   
       5 . The network device according to  claim 1 , wherein the network device is configured to obtain different distribution types, according to the plurality of values, for distributing incoming packets to ports of the plurality of ports. 
   
   
       6 . The network device according to  claim 1 , wherein the hasher is configured to hash three bits from each byte of the predefined fields to obtain an index bit for accessing one of the plurality of entries. 
   
   
       7 . The network device according to  claim 1 , wherein the plurality of ports are included in a trunk group. 
   
   
       8 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a destination address, a VLAN, an Ethertype, a source module identifier and a source port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       9 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a source address, a destination address, a VLAN, an Ethertype, a source module identifier and a source port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       10 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a source IP address and a TCP source port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       11 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a destination IP address and a TCP destination port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       12 . A network device comprising:
 a plurality of ports;   a table comprising a plurality of entries, wherein each entry is associated with one of the plurality of ports;   a hasher configured to hash a predefined number of bits from predefined fields in a unicast packet to select one entry in the table, the predefined fields including a source IP address, a TCP source port, a destination IP address and a TCP destination port; and   a transmitter configured to transmit the unicast packet to one of the plurality of ports based on the entry in the table selected by the hasher.   
   
   
       13 . A method for selecting a port from a trunk group to transmit a unicast packet on the selected port, the method comprising:
 associating, by a network device, each entry of a table with a trunk group, the trunk group comprising a plurality of ports;   storing information associated with one of the plurality of ports in each of a plurality of fields of each entry;   hashing bits from predefined fields of a unicast packet, the predefined fields including:
 a source address, a VLAN, an Ethertype, a source module identifier and a source port; or 
 a destination address, a VLAN, an Ethertype, a source module identifier and a source port; or 
 a source address, a destination address, a VLAN, an Ethertype, a source module identifier and a source port; or 
 a source IP address, and a TCP source port; or 
 a destination IP address, and a TCP destination port; or 
 a source IP address, a TCP source port, a destination IP address and a TCP destination port; 
   accessing one of the plurality of fields based on the hashing; and   transmitting the unicast packet to a port associated with the accessed field.   
   
   
       14 . The method according to  claim 13 , further comprising storing, if the trunk group comprises less than eight ports, redundant information from at least one of the plurality of fields in at least another one of the plurality of fields. 
   
   
       15 . The method according to  claim 13 , wherein the table is configured as a 128 entry table, wherein each entry comprises fields for eight ports. 
   
   
       16 . The method according to  claim 13 , wherein each of the plurality of fields includes an identifier for the network device and an identifier for one of the plurality of ports in the trunk group. 
   
   
       17 . The method according to  claim 13 , further comprising obtaining different distribution types, according to the plurality of values, for distributing incoming packets to ports of the trunk group. 
   
   
       18 . The method according to  claim 13 , wherein the hashing comprises hashing three bits from each byte of the predefined fields to obtain an index bit for accessing one of the plurality of entries.