Host route convergence based on sequence values

Abstract

In an example embodiment, a method is provided that assigns a sequence value to a host. The host is identified by a host network layer address. After the assignment, the host network layer address and the sequence value are included in an advertisement for transmission. In another example embodiment, another method is provided. Here, a first sequence value associated with the host network layer address is received from a network device. In addition, a second sequence value associated with the same host network layer address is received from a different network device. The first sequence value is ranked relative to the second sequence value and data is transmitted to the network device based on the ranking.

What is claimed is: 
     
       1. A method at a network device, the method comprising:
 at a network switch:
 receiving a previous advertisement including a host network layer address of a host and an existing sequence value associated with the host network layer address; 
 after the receiving, detecting that the host is associated with the network switch, the host being a device or a program application that provides a service; 
 generating a sequence value at the network switch based on the detecting, the generating including changing the received existing sequence value to a next sequential value that represents the sequence value; 
 associating the sequence value with the host network layer address of the host; and 
 transmitting an advertisement to a different network switch, the advertisement including the host network layer address and the sequence value. 
 
 
     
     
       2. The method of  claim 1 , wherein the advertisement includes a network layer address of the network switch, the host being in communication with the network switch. 
     
     
       3. The method of  claim 1 , wherein the generating the sequence value comprises:
 incrementing the received existing sequence value to the next sequential value. 
 
     
     
       4. The method of  claim 1 , wherein the generating the sequence value comprises:
 decreasing the received existing sequence value to the next sequential value. 
 
     
     
       5. The method of  claim 1 , wherein the existing sequence value includes a letter, and the changing the sequence value includes changing the letter to a next sequential letter that represents the sequence value. 
     
     
       6. The method of  claim 5 , wherein the changing the letter includes increasing the letter to the next sequential letter that represents the sequence value. 
     
     
       7. The method of  claim 5 , wherein the changing the letter includes decreasing the letter to the next sequential letter that represents the sequence value. 
     
     
       8. An apparatus comprising:
 a network switch including: 
 a processor; and 
 a memory in communication with the processor, the memory comprising instructions executable by the processor, when the instructions are executed the processor being operable to:
 receive a previous advertisement including a host network layer address of a host and an existing sequence value associated with the host network layer address; 
 after the previous advertisement is received, generate, based on detecting that the host is associated with the network switch, a sequence value at the network switch, wherein the processor is configured to generate by changing the received existing sequence value to a next sequential value that represents the sequence value, the host being a device or a program application that provides a service; 
 associate the sequence value with the host network layer address of the host; and 
 transmit an advertisement to a different network switch, the advertisement including the host network layer address and the sequence value. 
 
 
     
     
       9. The apparatus of  claim 8 , wherein the advertisement includes a network layer address of the network switch, the host being in communication with the network switch. 
     
     
       10. The apparatus of  claim 8 , wherein the processor is further operable to:
 increment the received existing sequence value to the next sequential value. 
 
     
     
       11. The apparatus of  claim 8 , wherein the processor is further operable to:
 decrease the received existing sequence value to the next sequential value. 
 
     
     
       12. A non-transitory machine-readable storage medium comprising instructions that, when executed by one or more processors of a network switch, cause the network switch to perform operations comprising:
 receiving a previous advertisement including a host network layer address of a host and an existing sequence value associated with the host network layer address; 
 after the receiving, detecting that the host is associated with the network switch, the host being a device or a program application that provides a service; 
 generating a sequence value at the network switch based on the detecting, the generating including changing the received existing sequence value to a next sequential value that represents the sequence value; 
 associating the sequence value with the host network layer address of the host; and 
 transmitting an advertisement to a different network switch, the advertisement including the host network layer address and the sequence value. 
 
     
     
       13. The storage medium of  claim 12 , wherein the advertisement includes a network layer address of the network switch, the host being in communication with the network switch. 
     
     
       14. The storage medium of  claim 12 , wherein the generating the sequence value comprises:
 incrementing the received existing sequence value to the next sequential value. 
 
     
     
       15. The storage medium of  claim 12 , wherein the generating the sequence value comprises:
 decreasing the received existing sequence value to the next sequential value.