System and method for dead gateway detection

1. A method for detecting a next-hop dead gateway, comprising:

sending an Internet Protocol (IP) packet by a host to a next-hop gateway associated with the host, and wherein source and destination fields in IP header associated with the IP packet includes IP address associated with the host, and wherein protocol field associated with the IP packet includes experimentation and testing code, and wherein IP payload field associated with the IP packet includes a unique identifier that indicates an IP packet is sent to detect the next-hop dead gateway;

receiving the IP packet by the host from the next-hop gateway upon reviewing a routing table and the destination field in the IP header associated with the IP packet;

determining whether the IP packet is received from the next-hop gateway within a first predetermined time interval, wherein determining whether the IP packet is received from the next-hop gateway within the first predetermined time interval comprises:

determining whether the protocol field and the IP payload field include the experimentation and testing code, and the unique identifier, respectively, by the host;

if so, then declaring the IP packet as a packet sent to detect a next-hop dead gateway by the host; and

determining whether the IP packet is received within the first predetermined time interval;

if so, declaring the next-hop gateway as alive; and

if not, declaring the next-hop gateway as dead.

2. The method of claim 1 , further comprising:

encapsulating the IP packet with a data link layer protocol associated with the host and the next-hop gateway.

3. The method of claim 1 , further comprising:

sending an Internet control message protocol (ICMP) ping packet request by the host to the next-hop gateway if the IP packet is not received within the first predetermined time interval;

determining whether a ICMP ping packet response is received by the host from the next-hop gateway within a third predetermined time interval; and

declaring the next-hop gateway as alive if the ping response is received within the third predetermined time interval.

4. The method of claim 3 , further comprising:

determining whether the underlying network is Ethernet based network if the ping response is not received within the third predetermined time interval; and

if not, declaring the next-hop gateway as dead.

5. The method of claim 4 , further comprising:

sending a unicast address resolution protocol (ARP) request packet by the host to the next-hop gateway if the underlying network is Ethernet based network;

determining whether the unicast ARP response is received by the host from the next-hop gateway within a fourth predetermined time interval;

if not, then declaring the next-hop gateway as dead and repeating sending the IP packet by the host, receiving the IP packet by the host, and determining steps after a second predetermined time interval; and

if so, declaring the next-hop gateway as alive and repeating sending the IP packet by the host, receiving the IP packet by the host, and determining steps after a second predetermined time interval.

6. The method of claim 1 , further comprising:

determining whether there is another next-hop gateway associated with the host;

if not, repeating sending the IP packet by the host, receiving the IP packet by the host and the determining steps to determine if the next-hop dead gateway is alive; and

if so, repeating sending the IP packet by the host, receiving the IP packet by the host, and the determining steps on the determined other next-hop gateway.

7. The method of claim 1 , further comprising:

selecting an alternate next-hop gateway associated with the host upon declaring the next-hop gateway as dead to send a packet of data from the host.

8. An article, comprising:

a storage medium having instructions, that when executed by a computing platform, result in execution of method of detecting a next-hop dead gateway, comprising:

sending an IP packet by a host to a next-hop gateway associated with the host and, wherein source and destination fields in IP header associated with the IP packet includes IP address associated with the host, and wherein protocol field associated with the IP packet includes experimentation and testing code, and wherein IP payload field associated with the IP packet includes a unique identifier that indicates an IP packet is sent to detect the next-hop dead gateway;

receiving the IP packet by the host from the next-hop gateway upon reviewing a routing table and the destination field in the IP header associated with the IP packet;

determining whether the IP packet is received from the next-hop gateway within a first predetermined time interval, wherein determining whether the IP packet is received from the next-hop gateway within the first predetermined time interval comprises:

determining whether the protocol field and the IP payload field include the experimentation and testing code, and the unique identifier, respectively, by the host;

if so, then declaring the IP packet as a packet sent to detect a next-hop dead gateway by the host; and

determining whether the IP packet is received within the first predetermined time interval;

if so, declaring the next-hop gateway as alive; and

if not, declaring the next-hop gateway as dead.

9. The article of claim 8 , further comprising:

encapsulating the IP packet with a data link layer protocol associated with the host and the next-hop gateway.

10. The article of claim 8 , further comprising:

selecting an alternate next-hop gateway associated with the host upon declaring the next-hop gateway as dead to send a packet of data from the host.

11. A computer system comprising:

a plurality of hosts;

a plurality of gateways coupled to the plurality of hosts; and

a memory coupled to one of the plurality of hosts, the memory having stored therein code which when decoded by the one of the plurality of hosts, the code causes the one of the plurality of hosts to perform a method for detecting a next-hop dead gateway, comprising:

sending an IP packet by a host to a next-hop gateway associated with the host, and wherein source and destination fields in IP header associated with the IP packet includes IP address associated with the host, and wherein protocol field associated with the IP packet includes experimentation and testing code, and wherein IP payload field associated with the IP packet includes a unique identifier that indicates an IP packet is sent to detect the next-hop dead gateway;

receiving the IP packet by the host from the next-hop gateway upon reviewing a routing table and the destination field in the IP header associated with the IP packet;

determining whether the IP packet is received from the next-hop gateway within a first predetermined time interval, wherein determining whether the IP packet is received from the next-hop gateway within the first predetermined time interval comprises:

determining whether the protocol field and the IP payload field include the experimentation and testing code, and the unique identifier, respectively, by the host;

if so, then declaring the IP packet as a packet sent to detect a next-hop dead gateway by the host; and

determining whether the IP packet is received within the first predetermined time interval;

if so, declaring the next-hop gateway as alive; and

if not, declaring the next-hop gateway as dead.