Method for preventing control packet loop and bridge apparatus using the method

• US 20060007869A1
• Filed: 12/28/2004
• Published: 01/12/2006
• Est. Priority Date: 07/09/2004
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hirota, Masaki, Takatori, Kou, Nishimura, Kazuto, Sasakawa, Yasushi
• Granted Patent: US 8,582,467 B2
• Time in Patent Office: Days
• US Class Current: 370/244
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 47/323 Discarding or blocking control packets, e.g. ACK packets

Abstract

A method for preventing a control packet loop in a network realizing node redundancy or circuit redundancy based on a rapid spanning tree protocol or a multiple spanning tree protocol is disclosed. The method includes the steps of: detecting a loop of a control packet of the rapid spanning tree protocol or the multiple spanning tree protocol; and discarding the control packet by which the loop is detected so as to prevent occurrence of the loop of the control packet.

Claims

1. A method for preventing a control packet loop in a network realizing node redundancy or circuit redundancy based on a rapid spanning tree protocol or a multiple spanning tree protocol, the method comprising the steps of:

detecting a loop of a control packet of the rapid spanning tree protocol or the multiple spanning tree protocol; and

discarding the control packet by which the loop is detected so as to prevent occurrence of the loop of the control packet.

2. A bridge apparatus for preventing a control packet loop in a network realizing node redundancy or circuit redundancy based on a rapid spanning tree protocol or a multiple spanning tree protocol, the bridge apparatus comprising:

a loop detection part for detecting a loop of a control packet of the rapid spanning tree protocol or the multiple spanning tree protocol; and

a control loop discarding part for discarding the control packet by which the loop is detected.

3. The bridge apparatus as claimed in claim 2, wherein the bridge apparatus is connected to a root bridge, and the control message is received after the bridge apparatus ages out information of the root bridge, wherein,

the loop detection part detects the loop of the control packet on condition that a root bridge priority and a root bridge address included in the control packet are the same as a priority and an address of the root bridge and that a message age in the control packet is not 0.

4. The bridge apparatus as claimed in claim 2, wherein, when a priority of the bridge apparatus that is a root bridge is changed, the loop detection part detects the loop of the control packet on condition that a root bridge address included in the control packet is the same as an address of the bridge apparatus and that a root bridge priority included in the control packet is different from the changed priority of the bridge apparatus.

5. The bridge apparatus as claimed in claim 3, wherein the loop detection part detects the loop by using the control packet that is received within a predetermined time period after aging out the information.

6. The bridge apparatus as claimed in claim 2, wherein the bridge apparatus is connected to a root bridge, and the control message is received after the bridge apparatus ages out information of the root bridge, wherein,

the loop detection part detects the loop of the control packet on condition that a root bridge priority and a root bridge address included in the control packet are the same as a priority and an address of the root bridge and that a path cost in the control packet is not 0.

7. The bridge apparatus as claimed in claim 2, wherein the bridge apparatus is connected to a root bridge, and the control message is received after the bridge apparatus ages out information of the root bridge, wherein,

the loop detection part detects the loop of the control packet on condition that a root bridge priority and a root bridge address included in the control packet are the same as a priority and an address of the root bridge and that a message age in the control packet is a predetermined value.

8. The bridge apparatus as claimed in claim 2, wherein the bridge apparatus is connected to a root bridge, and the control message is received after the bridge apparatus ages out information of the root bridge, wherein,

the loop detection part detects the loop of the control packet on condition that a root bridge priority and a root bridge address included in the control packet are the same as a priority and an address of the root bridge and that a path cost in the control packet is a predetermined value.

9. The bridge apparatus as claimed in claim 2, wherein the bridge apparatus is connected to a root bridge, and the control message is received after the bridge apparatus ages out information of the root bridge, wherein,

the loop detection part detects the loop of the control packet on condition that a root bridge priority and a root bridge address included in the control packet are the same as a priority and an address of the root bridge and that an input port that receives the control packet is an input port connected to a bridge other than the root bridge.

10. The bridge apparatus as claimed in claim 4, the control packet is received within a predetermined time period after a bridge priority of the bridge apparatus is changed.

11. The bridge apparatus as claimed in claim 2, wherein, when a priority of the bridge apparatus that is a root bridge is changed, the loop detection part detects the loop of the control packet on condition that a root bridge address included in the control packet is the same as an address of the bridge apparatus and that a root bridge priority included in the control packet is different from the changed priority of the bridge apparatus and that a message age in the control packet is not 0.

12. The bridge apparatus as claimed in claim 2, wherein, when a priority of the bridge apparatus that is a root bridge is changed, the loop detection part detects the loop of the control packet on condition that a root bridge address included in the control packet is the same as an address of the bridge apparatus and that a root bridge priority included in the control packet is different from the changed priority of the bridge apparatus and that a path cost in the control packet is not 0.

13. The bridge apparatus as claimed in claim 2, wherein, when a priority of the bridge apparatus that is a root bridge is changed, the loop detection part detects the loop of the control packet on condition that a root bridge address included in the control packet is the same as an address of the bridge apparatus and that a root bridge priority included in the control packet is different from the changed priority of the bridge apparatus and that a message age in the control packet is a predetermined value.

14. The bridge apparatus as claimed in claim 2, wherein, when a priority of the bridge apparatus that is a root bridge is changed, the loop detection part detects the loop of the control packet on condition that a root bridge address included in the control packet is the same as an address of the bridge apparatus and that a root bridge priority included in the control packet is different from the changed priority of the bridge apparatus and that a path cost in the control packet is a predetermined value.