Reducing false alarms when using network keep-alive messages

• US 10,374,936 B2
• Filed: 12/30/2015
• Issued: 08/06/2019
• Est. Priority Date: 12/30/2015
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Singh, Prashant, Neelam, Sairam
• Primary Examiner(s): Lazaro, David R
• Assistant Examiner(s): Henry, Mariegeorges A
• Application Number:
  US14/984,926
• Publication Number:
  US 20170195209A1
• Time in Patent Office: 1,315 Days
• Field of Search: 709223, 370248
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 45/026 Details of "hello" or keep-alive messages
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 47/2466 using signalling traffic
• CPC Class Codes: H04L 67/145 avoiding end of session, e.g. keep-alive, heartbeats, resumption message or wake-up for inactive or interrupted session
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols

Abstract

Techniques are described to reduce false alarms in network devices utilizing keepalive messaging schemes. In order to potentially avoid false alarms, a transmitting network device adjusts quality of service QOS/TOS settings in keep-alive probe packets that are sent later in a current detection interval such that the keep-alive probe packets have escalating priorities. In addition, for keep-alive probe packets that are sent later in the current detection interval, the network device may also insert host-level preferential indicator within each of the packets to request preferential treatment at both itself and the peer network device.

Claims

1. A method comprising:

maintaining, with a network device, a keep-alive transmit timer and a keep-alive detection timer associated with a communication session with a peer network device within a network, wherein the keep-alive transmit timer defines a transmit time interval for transmitting keep-alive probe packets for the communication session and the keep-alive detection timer defines a current detection interval within which a response communication from the peer network device must be received to avoid a failure event for the communication session;

responsive to expiration of the keep-alive transit timer during the current detection interval, outputting, by the network device, a first keep-alive probe packet associated with the communication session with the peer network device, wherein the first keep-alive probe packet includes quality of service (QoS) settings that control forwarding priority of the keep-alive probe packet by packet-switching devices within the network, and wherein the QoS settings have a value indicating a first priority level; and

responsive to a second expiration of the keep-alive transit timer associated with the current detection interval, determining, by the network device, whether a communication has been received from the peer network device since output of the first keep-alive probe packet and, when the communication has not been received, outputting a second keep-alive probe packet associated with the communication session, wherein the second keep-alive probe packet includes QoS settings having a value indicating a second priority level increased from the first priority level.

2. The method of claim 1,

wherein the first keep-alive probe packet and the second keep-alive probe packet each includes a host-level preferential indicator separate from the QoS settings that specifies preferential treatment for the first keep-alive probe packet by packet processing software or hardware on the network device when outputting the first keep-alive probe packet and by packet processing software or hardware on the peer network device when receiving the first keep-alive probe packet,

wherein the network device sets the host-level preferential indicator of the first keep-alive probe packet to have a first value indicating that preferential treatment is not requested, and

wherein, when the communication from the peer network device has not been received, the network device sets the host-level preferential indicator of the second keep-alive probe packet to have a second value indicating that preferential treatment is requested.

3. The method of claim 2, wherein the host-level preferential indicator comprise one of:

a flag set within a reserved Transmission Control Protocol (TCP) bit, a flag set within an unused bidirectional forwarding detection (BFD) protocol diagnostic bit, or an unused Internet Protocol (IP) options bit.

4. The method of claim 1, wherein the communication from the peer network device comprises a keep-alive response packet sent by the peer network device to the network device on the communication session.

5. The method of claim 1, wherein the communication from the peer network device comprises a keep-alive probe packet sent by the peer network device to the network device on a second communication session.

6. The method of claim 1,

wherein the communication session comprises a bidirectional forwarding detection (BFD) protocol session between the network device and the peer network device,

wherein the first keep-alive probe packet and the second keep-alive probe packets output by the network device comprises BFD keep-alive probe packets, and

wherein the communication from the peer network device comprises a BFD keep-alive probe packet sent by the peer network device to the network device on a second communication session.

7. The method of claim 1,

further comprising:

receiving, by the peer network device, the first keep-alive probe packet;

constructing, with the peer network device, a keep-alive response packet, wherein constructing the keep-alive response packet includes copying the QoS settings of the first keep-alive probe packet to QoS settings within the keep-alive response packet; and

outputting the keep-alive response packet from the peer device to the network device.

8. The method of claim of claim 7,

wherein the first keep-alive probe packet includes a host-level preferential indicator that specifies preferential treatment for the first keep-alive probe packet by packet processing software or hardware on the network device when outputting the first keep-alive probe packet and by packet processing software or hardware on the peer network device when receiving the first keep-alive probe packet, and

wherein constructing the keep-alive response packet with the peer network device includes copying the host-level preferential indicator of the first keep-alive probe packet received from the network device to a host-level preferential indicator within the keep-alive response packet.

9. A method comprising:

receiving, by a network device, a keep-alive probe packet associated with a communication session with a peer network device within a network, wherein the keep-alive probe packet includes quality of service (QoS) settings that controls forwarding priority of the keep-alive probe packet by packet-switching devices within the network;

constructing, with the network device, a keep-alive response packet, wherein constructing the keep-alive response packet includes copying the QoS settings of the keep-alive probe packet to QoS settings within the keep-alive response packet; and

outputting the keep-alive response packet from the network device to the peer network device;

wherein the keep-alive probe packet includes a host-level preferential indicator that specifies preferential treatment for the keep-alive probe packet by packet processing software or hardware on the network device when receiving the keep-alive probe packet and by packet processing software or hardware on the peer network device when transmitting the keep-alive probe packet, and

wherein constructing the keep-alive response packet with the network device includes copying the host-level preferential indicator of the keep-alive probe packet received from the network device to a host-level preferential indicator within the keep-alive response packet.

10. A network device comprising:

one or more programmable processors coupled to a memory storing instructions and at least one network interface; and

wherein, when executing the instructions, the processor is configured to;

maintain a keep-alive transmit timer and a keep-alive detection timer associated with a communication session with a peer network device within a network, wherein keep-alive transmit timer defines a transmit time interval for transmitting keep-alive probe packets for the communication session and the keep-alive detection timer defines a current detection interval within which a response communication from the peer network device must be received to avoid a failure event for the communication session;

responsive to expiration of the keep-alive transit timer during the current detection interval, output a first keep-alive probe packet associated with the communication session with the peer network device, wherein the first keep-alive probe packet includes quality of service (QoS) settings that control forwarding priority of the keep-alive probe packet by packet-switching devices within the network, and wherein the QoS settings have a value indicating a first priority level;

responsive to a second expiration of the keep-alive transit timer associated with the current detection interval, determine whether a communication has been received from the peer network device since output of the first keep-alive probe packet and, when the communication has not been received, output a second keep-alive probe packet associated with the communication session, wherein the second keep-alive probe packet includes QoS settings having a value indicating a second priority level increased from the first priority level.

11. The network device of claim 10,

wherein the first keep-alive probe packet and the second keep-alive probe packet each includes a host-level preferential indicator separate from the QoS settings that specifies preferential treatment for the first keep-alive probe packet by packet processing software or hardware on the network device when outputting the first keep-alive probe packet and by packet processing software or hardware on the peer network device when receiving the first keep-alive probe packet,

wherein the network device sets the host-level preferential indicator of the first keep-alive probe packet to have a first value indicating that preferential treatment is not requested, and

wherein, when the communication from the peer network device has not been received, the network device sets the host-level preferential indicator of the second keep-alive probe packet to have a second value indicating that preferential treatment is requested.

12. The network device of claim 11, wherein the host-level preferential indicator comprise one of:

a flag set within a reserved Transmission Control Protocol (TCP) bit, a flag set within an unused bidirectional forwarding detection (BFD) protocol diagnostic bit, or an unused Internet Protocol (IP) options bit.

13. The network device of claim 10, wherein the communication from the peer network device comprises a keep-alive response packet sent by the peer network device to the network device on the communication session.

14. The network device of claim 10, wherein the communication from the peer network device comprises a keep-alive probe packet sent by the peer network device to the network device on a second communication session.

15. The network device of claim 10,

wherein the communication session comprises a bidirectional forwarding detection (BFD) protocol session between the network device and the peer network device,

wherein the first keep-alive probe packet and the second keep-alive probe packets output by the network device comprises BFD keep-alive probe packets, and

wherein the communication from the peer network device comprises a BFD keep-alive probe packet sent by the peer network device to the network device on a second communication session.

16. A network device comprising:

one or more programmable processors coupled to a memory storing instructions and at least one network interface; and

wherein, when executing the instructions, the processor is configured to;

receive, by a network device, a keep-alive probe packet associated with a communication session with a peer network device within a network, wherein the keep-alive probe packet includes quality of service (QoS) settings that controls forwarding priority of the keep-alive probe packet by packet-switching devices within the network;

construct, with the network device, a keep-alive response packet, wherein constructing the keep-alive response packet includes copying the QoS settings of the keep-alive probe packet to QoS settings within the keep-alive response packet; and

output the keep-alive response packet from the network device to the peer network device;

wherein the keep-alive probe packet includes a host-level preferential indicator that specifies preferential treatment for the keep-alive probe packet by packet processing software or hardware on the network device when receiving the keep-alive probe packet and by packet processing software or hardware on the peer network device when transmitting the keep-alive probe packet, and

wherein constructing the keep-alive response packet with the network device includes copying the host-level preferential indicator of the keep-alive probe packet received from the network device to a host-level preferential indicator within the keep-alive response packet.