Preventing data traffic connectivity between endpoints of a network segment

A network device comprising:

• a first segment port configured to receive a segment protocol message from a second segment port within a network segment, wherein
• the network segment comprises a plurality of network devices,
• the first segment port is configured to drop data traffic being conveyed via the network segment if in a blocked state, and
• the segment protocol message comprises
• a port key, and
• a port priority;
• and
• a segment protocol module coupled to the first segment port, wherein the segment protocol module is configured to
• compare a first port priority of the first segment port with the port priority, in response to receipt of the segment protocol message,
• compare a first port key of the first segment port with the port key, in response to receipt of the segment protocol message,
• determine whether to send a responsive segment protocol message to the second segment port, in response to an outcome of a comparison of the first port priority with the port priority, and
• determine whether to operate the first segment port in the blocked state, in response to an outcome of a comparison of the first port key with the port key, wherein
• operation of the first segment port in the blocked state prevents data plane connectivity via the network segment, but does not prevent control plane connectivity, and
• the segment protocol message is a control plane message.

A system comprising:

• means for receiving a segment protocol message from a first segment port within
• a network segment, wherein
• the network segment comprises a plurality of network devices,
• the segment protocol message is received on a second segment port within the network segment, and
• the segment protocol message comprises
• a first port key, and
• a first port priority;
• means for comparing a second port priority of the second segment port with the first port priority, in response to receipt of the segment protocol message;
• means for comparing a second port key of the second segment port with the first port key, in response to receipt of the segment protocol message;
• means for determining whether to send a responsive segment protocol message to the first segment port, in response to an outcome of the means for comparing the second port priority;
• and
• means for determining whether to operate the second segment port in a blocked state, in response to an outcome of the means for comparing the second port key, wherein
• operation of the second segment port in the blocked state prevents data plane connectivity via the network segment but does not prevent control plane connectivity, and
• the segment protocol message is a control plane message.