Loop prevention techniques using encapsulation manipulation of IP/MPLS field

A network node configured to perform fast reroute (FRR) operations at the edge of a computer network, the network node comprising:

• a processor;
• a first network interface adapted to communicate with a neighboring routing domain;
• a second network interface adapted to receive a data packet containing a destination address that is reachable via the neighboring routing domain;
• and
• a memory adapted to store instructions which are executable by the processor for performing the steps:
• detecting a loss of communication over the first network interface;
• determining whether the received data packet contains a FRR identifier value in at least one of its encapsulation headers, the FRR identifier value indicating that the received packet was previously rerouted in accordance with FRR operations;
• and
• rerouting, in response to determining that the received data packet does not contain the FRR identifier value, the received data packet to the second edge device for forwarding to the neighboring routing domain.

A network node configured to perform fast reroute (FRR) operations at the edge of a computer network, the network node comprising:

• a first network interface adapted to communicate with a neighboring routing domain;
• means for detecting a loss of communication over the first network interface;
• a second network interface adapted to receive a data packet containing a destination address that is reachable via the neighboring routing domain;
• means for determining whether the received data packet contains a FRR identifier value in at least one of its encapsulation headers, the FRR identifier value indicating that the received packet was previously rerouted in accordance with FRR operations;
• and
• means for rerouting, in response to determining that the received data packet does not contain the FRR identifier value, the received data packet to the second edge device for forwarding to the neighboring routing domain.

A computer network, comprising:

• a first edge device coupled to a neighboring routing domain;
• and
• a second edge device coupled to the neighboring routing domain, the second edge device being configured to:
• detect a loss of communication with the neighboring routing domain;
• receive a data packet containing a destination address that is reachable via the neighboring routing domain;
• determine whether the received data packet contains a FRR identifier value in at least one of its encapsulation headers, the FRR identifier value indicating that the received packet was previously rerouted in accordance with FRR operations;
• and
• reroute, in response to determining that the received data packet does not contain the FRR identifier value, the received data packet to the first edge device for forwarding to the neighboring routing domain.

A computer-readable medium storing instructions for execution on a processor for the practice of a method of performing fast reroute (FRR) operations at the edge of a computer network, the network having first and second edge devices coupled to a neighboring routing domain, the method comprising:

• detecting a loss of communication between the first edge device and the neighboring routing domain;
• receiving a data packet at the first edge device, the received data packet containing a destination address that is reachable via the neighboring routing domain;
• determining whether the received data packet contains a FRR identifier value in at least one of its encapsulation headers, the FRR identifier value indicating that the received packet was previously rerouted in accordance with FRR operations;
• and
• rerouting, in response to determining that the received data packet does not contain the FRR identifier value, the received data packet to the second edge device for forwarding to the neighboring routing domain.