Advanced ethernet auto negotiation

A first network device, comprising:

• a port for connection to a network link;
• and
• port logic operative:
• (i) to transmit over the network link in a half duplex mode to at least a second network device;
• (ii) while transmitting in half duplex mode, to detect the occurrence of at least one collision on the network link indicative of a potential mis-configuration of the at least a second network device;
• and
• (iii) upon detecting the occurrence of such at least one collision, to commence transmitting over the network link in a full duplex mode to the at least a second network device.

A network, comprising:

• a first network device connected to a network link, the first network device being operative to transmit over the network link in a full duplex mode;
• and
• a second network device coupled to the first network device via the network link, the second network device being operative:
• (1) to initially transmit over the network link in a half duplex mode to the first network device, (2) while transmitting in the half duplex mode, to detect at least one error on the network link indicating that the first network device may be mis-configured, and (3) upon detecting such at least one error, to commence transmitting over the network link in a full duplex mode to the first network device.

A network device, comprising:

• a port for connection to a network link;
• and
• a port monitoring state machine operative:
• (i) during a first operational state, to engage in an auto-negotiation protocol on the network link;
• (ii) as a result of engaging in the auto-negotiation protocol on the network link, to enter a second operational state in which the port is operated in a half duplex mode;
• (iii) during the second operational state, to monitor the link for a first error condition indicating that another network device attached to the network link may be mis-configured;
• and
• (iv) upon detecting the first error condition in the second operational state, to enter a third operational state in which the port is operated in a full duplex mode.

A method for network communication through a network device port, comprising the steps of:

• during a first operational state, the device port engaging in an auto-negotiation protocol with a second network device associated with the network;
• entering a second operational state in response to the auto-negotiation protocol in which the network device port is operated in half duplex mode;
• during the second operational state, monitoring the link for a first error condition indicating that the second network device linked to the network may not be operating in half duplex mode;
• upon detecting the first error condition in the second operational state, entering a third operational state in which the network device port is operated in a full duplex mode;
• and
• during the third operational state, monitoring the network link for a second error condition indicating that the second network device may not be operating in full duplex mode, and in the absence of the second error condition, continuing to operate the network device port in full duplex mode.

A network, comprising:

• a first network device operative to communicate over a network link in a full duplex mode;
• and
• a second network device coupled to the first network device via the network link, the second network device being capable of employing auto negotiation so as to operate in either a full duplex mode or a half duplex mode on the network link, the second network device being operative:
• to initially operate over the network link in a half duplex mode;
• while operating in the half duplex mode, to monitor the communication between the first and second network devices for a first error condition;
• upon detecting the first error condition, to operate over the network link in a full duplex mode;
• while operating in the full duplex mode, to monitor the communication between the first and second network devices for a second error condition;
• and
• in the absence of the second error condition, to continue to operate over the network link in the full duplex mode.