Method and apparatus of handling data that is sent to non-existent destinations

• US 6,628,608 B1
• Filed: 03/26/1999
• Issued: 09/30/2003
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Chui, Gene, Chui, Frank, Samrao, Gurmohan, Kipnis, Gary, Lau, Onchuen
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/277,518
• Time in Patent Office: 1,649 Days
• Field of Search: 709/223, 709/224, 709/225, 370/216-220, 370/225-228, 370/241, 370/241.1, 370/242-6, 370/252, 370/400-402, 370/445, 370/449, 370/238, 370/389, 370/395.1, 370/395.32, 345/736
• US Class Current: 370/218
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/55 Prevention, detection or correction of errors
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9063 Intermediate storage in different physical parts of a node or terminal
• CPC Class Codes: H04L 49/9084 Reactions to storage capacity overflow

Abstract

A method of managing a network switch. The method having the first step of detecting a status of a set of physical ports on an interface card in the network switch. Then, determining if the status is in a first state that indicates that all physical ports in the interface card are inaccessible. If the status is in the first state, then accepting all traffic for the set of physical ports. Also disclosed is an apparatus for performing the method.

Claims

1. A method of managing a network switch comprising:

detecting, at a switch fabric that switches traffic received by the network switch, a status of a set of physical ports on an interface card in the network switch;

determining from the status that the set of physical ports is inaccessible

accepting, at the switch fabric, all traffic destined for the set of physical ports; and

discarding, at the switch fabric, all of the traffic destined for the set of physical ports.

2. The method of claim 1, wherein the status further comprises a card present signal.

3. A method of controlling a communications switching apparatus, comprising:

receiving a signal at a switch fabric included within the communications switching apparatus, the signal indicating that a first set of ports on an interface card contained in the communications switching apparatus is unreachable, the signal also indicating that a second set of ports on the interface card are functioning properly;

accepting, at the switch fabric, traffic destined for the first set of ports and traffic destined for the second set of ports; and

discarding at the switch fabric the traffic destined for the first set of ports and switching at the switch fabric the traffic destined for the second set of ports to the second set of ports.

4. A communications network, comprising:

a first network;

a second network;

a communications switching apparatus having;

a first interface coupled to the first network;

a second interface coupled to the second network; and

,

a switch fabric configured to transmit traffic between the first interface and the second interface, the switch fabric designed to;

(i) accept traffic from the second interface that is destined for the first interface even if the first interface is non-functional; and

(ii) discard the traffic in response to the first interface being non-functional;

the switch fabric also designed to;

(iii) accept traffic from the first interface that is destined for the second interface even if the second interface is non-functional; and

, (iv) discard the traffic that is destined for the second interface in response to the second interface being non-functional.

5. The communications network of claim 4, wherein the switch fabric receives a first status indicator from the first interface and a receives a second status interface from the second interface.

6. A network switch, comprising:

a first interface containing a first set of ports and a second set of ports; and

a switch fabric coupled to the first interface and the second interface, the switch fabric configured to receive a status signal from the first interface that indicates when the first set of ports is unreachable, the switch fabric configured to accept traffic destined for the first set of ports and discard the traffic in response to the status signal, the switch fabric configured to accept and switch traffic destined for the second set of ports.

7. The network switch of claim 6, wherein the network switch further comprises at least one other interface that:

1) receives at least a portion of the traffic that is destined for the first set of ports;

2) includes a buffer that queues the traffic it receives including the at least a portion of the traffic that is destined for the first set of ports, the accepting by the switch fabric of the at least a portion of the traffic destined for the first set of ports preventing congestion of the buffer.

8. A network switch comprising:

a first interface containing a set of ports;

a second interface that receives traffic destined for the set of ports, the second interface including a buffer that queues the traffic; and

,

a switch fabric coupled to the first interface and the second interface, the switch fabric configured to receive a status signal from the first interface that indicates whether;

(i) the set of ports is reachable;

or,

(ii) the set of ports is not reachable;

the switch fabric configured to;

(i) accept the traffic from the second interface regardless of whether or not the set of ports are reachable or unreachable as indicated by the status signal;

(ii) switch the traffic to the first interface if the status signal indicates that the set of ports is reachable;

(iii) discard the traffic if the status signal indicates that the first set of ports is not reachable.

9. The network switch of claim 8, wherein the status signal can indicate that the first interface is removed from the network switch, if the first interface is removed from the network switch, in which case, the set of ports is recognized as corresponding to all ports on the first interface.

10. An apparatus for managing a network switch comprising:

means for detecting, at a switch fabric that switches traffic received by the network switch, a status of a set of physical ports on an interface card in the network switch;

means for determining from the status that the set of physical ports is inaccessible;

means for accepting, at the switch fabric, all traffic destined for the set of physical; and

,

means for discarding, at the switch fabric, all of the traffic destined for the set of physical ports.

11. The apparatus of claim 10, wherein the status further comprises a card present signal.

12. An apparatus of controlling a communications switching apparatus, comprising:

means for receiving a signal at a switch fabric included within the communications switching apparatus, the signal indicating that a first set of ports on an interface card contained in the communications switching apparatus is in an inoperative state

means for accepting, at the switch fabric, traffic destined for the first set of ports and traffic destined for the second set of ports; and

discarding at the switch fabric the traffic destined for the first set of ports and switching at the switch fabric the traffic destined for the second set of ports to the second set of ports.

13. An article comprising a computer readable medium having instructions stored thereon, which when executed, causes:

determining if the status for a set of physical ports on an interface card in a network switch indicates that all physical ports in the interface card are inaccessible;

accepting, at the switch fabric, all traffic destined for the set of physical ports;

discarding at the switch fabric all of the traffic destined for the set of physical ports.

14. The article of claim 13, wherein the status further comprises a card present signal.