Miscabling detection protocol

Patent metadata

Field	Value
Publication number	US-9444634-B2
Application number	US-201414448733-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Nov 5, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Systems, methods, and non-transitory computer-readable storage media for a miscabling detection protocol. One or more switches can periodically send miscabling protocol (MCP) packets on non-fabric ports on all configured EPG VLANs. A first switch located at a network fabric receives a miscabling protocol (MCP) packet indicating an identity of an originating switch and a port number of an originating port of the MCP packet via a receiving port on the first switch, wherein the MCP packet is received from an external network connected to the receiving port, and wherein the originating switch and originating port are also located at the network fabric and connected to the external network. Based on the MCP packet, the first switch then detects a loop between the receiving port, the originating port, and the external network. Next, the first switch blocks the receiving port or the originating port in response to detecting the loop.

First claim

We claim:

1. A computer-implemented method comprising:
receiving, via a receiving non-fabric port on a receiving switch located on a network fabric, a miscabling protocol packet indicating an identity of an originating switch on the network fabric and an originating non-fabric port associated with the originating switch, wherein the miscabling protocol packet is received from an external network connected to the receiving non-fabric port, wherein the originating switch and originating non-fabric port are also located on the network fabric and connected to the external network, wherein the receiving non-fabric port and the originating non-fabric port are both:
on a same flood domain in the network fabric;
associated with different virtual local area networks or endpoint groups associated with the network fabric; and
assigned to a same virtual local area network on the external network; and

based on the miscabling protocol packet, detecting a loop between the receiving port, the originating port, and the external network; and
blocking at least one of the receiving port and the originating port associated with the miscabling protocol packet in response to detecting the loop.

2. The computer-implemented method of claim 1 , wherein the miscabling protocol packet further indicates at least one of a timestamp and a checksum value associated with the miscabling protocol packet.

3. The computer-implemented method of claim 2 , further comprising verifying an authenticity of the miscabling protocol packet based on at least one of the timestamp and the checksum value.

4. The computer-implemented method of claim 1 , wherein the miscabling protocol packet is addressed to a multicast address associated with a miscabling protocol, and wherein at least one of the originating non-fabric port and the receiving non-fabric port is connected to an overlay network.

5. The computer-implemented method of claim 1 , wherein the receiving switch comprises a leaf switch, and wherein the network fabric is based on a spine-leaf topology.

6. The computer-implemented method of claim 1 , wherein detecting the loop is based on a receipt of the miscabling protocol packet by the receiving switch.

7. The computer-implemented method of claim 1 , wherein identifying the loop is further based on a difference between a first address associated with the originating non-fabric port and a second address associated with the receiving non-fabric port.

8. The computer-implemented method of claim 1 , wherein detecting the loop is further based on at least one of a first determination that the originating switch is also the receiving switch and a second determination that the originating non-fabric port is also the receiving non-fabric port.

9. The computer-implemented method of claim 1 , wherein the external network comprises a layer 2 network.

10. The computer-implemented method of claim 9 , wherein the layer 2 network is set at the receiving non-fabric port and originating non-fabric port as a same bridge domain.

11. The computer-implemented method of claim 1 , wherein the receiving switch is configured to send at least one miscabling protocol packet periodically at configured intervals.

12. The computer-implemented method of claim 1 , wherein the receiving switch is configured to listen to miscabling protocol packets.

13. The computer-implemented method of claim 1 , further comprising:
sending at least one miscabling protocol packet for each configured virtual local area network on each of a plurality of non-fabric ports on the receiving switch, and
wherein detecting the loop is based on a determination that the miscabling protocol packet was sent by the originating non-fabric port over a first virtual local area network or endpoint group and received by the receiving non-fabric port on a second virtual local area network or endpoint group that is different than the first virtual local area network or endpoint group.

14. The computer-implemented method of claim 1 , wherein blocking at least one of the receiving non-fabric port and the originating non-fabric port is based on respective identities of the receiving non-fabric port and the originating non-fabric port, the method further comprising unblocking the at least one of the receiving non-fabric port and the originating non-fabric port after a timeout period.

15. The computer-implemented method of claim 14 , wherein the unblocking is based on a strict mode where only one or more specific type of packets are allowed and other packets are blocked for at least a period of time.

16. A system comprising:
a processor; and
a computer-readable storage medium having stored therein instructions which, when executed by the processor, cause the processor to perform operations comprising:
receiving, via a receiving non-fabric port in a network fabric, a miscabling protocol packet indicating an identity of an originating switch in the network fabric and an originating non-fabric port associated with the miscabling protocol packet, wherein the miscabling protocol packet is received from an external network coupled with the receiving non-fabric port, and wherein the originating switch, the originating non-fabric port and the receiving non-fabric port are all located on the network fabric and coupled with the external network, and wherein the receiving non-fabric port and the originating non-fabric port are both:
on a same flood domain in the network fabric;
assigned to different virtual local area networks or endpoint groups in the network fabric; and
assigned to a same virtual local area network on the external network; and

based on the miscabling protocol packet, identifying a loop between the receiving non-fabric port on the network fabric, the originating non-fabric port on the network fabric, and the external network; and
re-configuring at least one of the originating non-fabric port and the receiving non-fabric port.

17. The system of claim 16 , wherein re-configuring at least one of the originating non-fabric port and the receiving non-fabric port comprises blocking at least a portion of traffic on at least one of the originating non-fabric port and the receiving non-fabric port.

18. The system of claim 16 , wherein identifying the loop is based on at least one of:
a determination that:
the system comprises both the originating switch and a receiving switch associated with the receiving non-fabric port; and
the system has both originated the miscabling protocol packet and received the miscabling protocol packet from the external network; or

a determination that:
the miscabling protocol packet was originated by a non-fabric port located in the network fabric where the receiving non-fabric port resides; and
the miscabling protocol packet was sent by the originating non-fabric port towards the external network via a first virtual local area network or endpoint group and received by the receiving non-fabric port from the external network via a second virtual local area network or endpoint group that is different than the first virtual local area network or endpoint group.

19. The system of claim 16 , wherein re-configuring at least one of the originating non-fabric port and the receiving non-fabric port comprises blocking a selected one of the originating non-fabric port or the receiving non-fabric port, the selected one of the originating non-fabric port or the receiving non-fabric port being selected based on a comparison of a first address associated with the originating switch and a second address associated with

Assignees

• Cisco Tech Inc

Inventors

• Pani Ayaskant
• Yadav Navindra
• Doddapaneni Krishna

Classifications

• H04L41/12

  Discovery or management of network topologies · CPC title

• H04L41/0894

  Policy-based network configuration management · CPC title

• H04L41/082

  the condition being updates or upgrades of network functionality · CPC title

• H04L12/4633

  Interconnection of networks using encapsulation techniques, e.g. tunneling · CPC title

• H04L61/103

  across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP] · CPC title