US 7,522,595 B2
Communicating packets between forwarding contexts using virtual interfaces
Nir Ben-Dvora, Herzltya (Israel); Doron Oz, Even Yehuda (Israel); Sarel Altshuler, Haifa (Israel); and Warren Scott Wainner, Potomac Falls, Va. (US)
Assigned to Cisco Technology, Inc., San Jose, Calif. (US)
Filed on Jun. 16, 2006, as Appl. No. 11/454,278.
Prior Publication US 2007/0291752 A1, Dec. 20, 2007
Int. Cl. H04L 12/28 (2006.01)
U.S. Cl. 370—389  [370/230; 370/235; 370/351; 370/395.31; 370/400; 709/211; 709/215; 709/229; 709/238] 32 Claims
OG exemplary drawing
 
16. An apparatus for processing packets including the ability to move packets between forwarding contexts in a packet switching device, the apparatus comprising:
a plurality of different forwarding contexts configured to identify forwarding information for packets based on their respective forwarding information base;
a context forwarder configured to forward packets among the plurality of different forwarding contexts;
a plurality of back-to back virtual interface pairings, each of said back-to-back virtual interface pairings including a first virtual interface and a second virtual interface, wherein the first virtual interface of each of said back-to-back virtual interface pairings is associated with a different one of the plurality of different forwarding contexts, and wherein the second virtual interface of each of said back-to-back virtual interface pairings is associated with the context forwarder; and
a first forwarding context application processor associated with at least one of said plurality of different forwarding contexts configured to apply one or more features to packets received by the first virtual interface of said at least one of said plurality of different forwarding contexts before forwarding said received packets from the first virtual interface;
wherein the context forwarder is configured to receive packets on the second virtual interfaces of said back-to-back virtual interface pairings and for each particular packet of said received packets on the second virtual interfaces, to identify which particular forwarding context of said plurality of different forwarding contexts to which to forward to said particular packet and to move said particular packet to said second interface of the plurality of back-to-back virtual interface pairings corresponding to said particular forwarding context; and wherein the apparatus is configured to move packets received on said first interface automatically to said second interface of each of the plurality of back-to-back virtual interface pairings and to move packets received on said second interface automatically to said first interface of each of the plurality of back-to back virtual interface pairings.