Dynamic Host Configuration Protocol (DHCP) Initialization Responsive to a Loss of Network Layer Connectivity

• US 20090210522A1
• Filed: 09/04/2008
• Published: 08/20/2009
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Droms, Ralph, Ward, David Delano, Vinokour, Vitali
• Granted Patent: US 8,078,721 B2
• Time in Patent Office: Days
• US Class Current: 709/222
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with loss of network layer connectivity triggering Dynamic Host Configuration Protocol (DHCP) initialization. According to one embodiment, a network device connected to a network initializes one or more network communication values of the network device using DHCP. The network device monitors Network Layer (Layer 3) connectivity with a remote network device; and in response to detecting a loss of said monitored Network Layer connectivity, DHCP initialization of the network device is performed.

Claims

1. An apparatus, comprising:

one or more network interfaces configured to communicate over a network, including with a Dynamic Host Configuration Protocol (DHCP) server; and

one or more processing elements configured;

(a) to set one or more network communication values of the apparatus using DHCP in communication with the DHCP server, with said one or more communications values including a particular network address;

(b) to monitor Network Layer (Layer

     3) connectivity; and

(c) to cause the apparatus, in response to a loss of said monitored Network Layer connectivity, to perform DHCP initialization with the particular network address.

2. The apparatus of claim 1, wherein said causing the apparatus, in response to the loss of said monitored Network Layer connectivity, to perform DHCP initialization with the particular network address includes causing said initialization despite maintaining Data Link Layer (L2) connectivity on a particular interface of said one or more interfaces, wherein said detected loss of said monitored Network Layer connectivity is on the particular interface.

3. The apparatus of claim 1, wherein said DHCP initialization with the particular network address includes the apparatus entering a DHCP INIT-REBOOT state and sending a DHCPREQUEST message to the DHCP server.

4. The apparatus of claim 3, wherein said monitoring L3 connectivity includes using a Bidirectional Forwarding Detection (BFD) session with a remote networked device.

5. The apparatus of claim 4, wherein said causing the apparatus, in response to the loss of said monitored Network Layer connectivity, to perform DHCP initialization with the particular network address includes causing said initialization despite maintaining Data Link Layer (L2) connectivity on a particular interface of said one or more interfaces, wherein the BFD session is communicated via the particular interface.

6. The apparatus of claim 3, wherein said one or more processing elements are configured to restart the DHCP initialization process in response to receiving a DHCPNAK message from the DHCP server in response to said DHCPREQUEST message sent to the DHCP server.

7. The apparatus of claim 1, wherein said monitoring L3 connectivity includes using a Bidirectional Forwarding Detection (BFD) session with a remote networked device.

8. The apparatus of claim 7, wherein said causing the apparatus, in response to the loss of said monitored Network Layer connectivity, to perform DHCP initialization with the particular network address includes causing said initialization despite maintaining Data Link Layer (L2) connectivity on a particular interface of said one or more interfaces, wherein the BFD session is communicated via the particular interface.

9. An apparatus, comprising:

one or more network interfaces configured to communicate over a network, including with a Dynamic Host Configuration Protocol (DHCP) server; and

one or more processing elements configured;

(a) to set one or more network communication values of the apparatus using DHCP in communication with the DHCP server, with said one or more communications values including a network address;

(b) to monitor Network Layer (Layer

     3) connectivity; and

(c) to cause the apparatus, in response to a loss of said monitored Network Layer connectivity, to perform DHCP initialization from a DHCP INIT state.

10. The apparatus of claim 9, wherein said monitoring L3 connectivity includes using a Bidirectional Forwarding Detection (BFD) session with a remote networked device.

11. The apparatus of claim 10, wherein said causing the apparatus, in response to the loss of said monitored Network Layer connectivity, to perform DHCP initialization from a DHCP INIT state includes causing said initialization despite maintaining Data Link Layer (L2) connectivity on a particular interface of said one or more interfaces, wherein said detected loss of said monitored Network Layer connectivity is on the particular interface.

12. A method performed by a network device connected to a network, the method comprising:

initializing one or more network communication values of the network device using Dynamic Host Configuration Protocol (DHCP);

monitoring Network Layer (Layer

     3) connectivity with a remote network device; and

in response to detecting a loss of said monitored Network Layer connectivity, performing DHCP initialization of the network device.

13. The method of claim 12, wherein said one or more network values includes a particular network address;

and said DHCP initialization is performed with the particular network address.

14. The method of claim 13, wherein said DHCP initialization with the particular network address includes entering a DHCP INIT-REBOOT state and sending a DHCPREQUEST message to a DHCP server.

15. The method of claim 14, wherein said monitoring Network Layer (Layer 3) connectivity includes establishing a Bidirectional Forwarding Detection (BFD) session with a remote networked device;

and wherein said detecting the loss of said monitored Network Layer connectivity occurs based on the BFD session.

16. The method of claim 15, wherein the network device maintains Data Link Layer (L2) connectivity on a particular network interface of the network device during said operations of said detecting a loss of said monitored Network Layer connectivity and said performing DHCP initialization of the network device, wherein said monitoring Network Layer (Layer 3) connectivity with the remote network device is performed over the particular network interface.

17. The method of claim 12, wherein said DHCP initialization of the network device includes performing DHCP initialization from a DHCP INIT state.

18. The method of claim 17, wherein said monitoring Network Layer (Layer 3) connectivity includes establishing a Bidirectional Forwarding Detection (BFD) session with a remote networked device;

and wherein said detecting the loss of said monitored Network Layer connectivity occurs based on the BFD session.

19. The method of claim 12, wherein said monitoring Network Layer (Layer 3) connectivity includes establishing a Bidirectional Forwarding Detection (BFD) session with a remote networked device;

and wherein said detecting the loss of said monitored Network Layer connectivity occurs based on the BFD session.

20. The method of claim 12, wherein the network device maintains Data Link Layer (L2) connectivity on a particular network interface of the network device during said operations of said detecting a loss of said monitored Network Layer connectivity and said performing DHCP initialization of the network device, wherein said monitoring Network Layer (Layer 3) connectivity with the remote network device is performed over the particular network interface.

21. An apparatus, comprising:

means for initializing one or more network communication values of the apparatus using Dynamic Host Configuration Protocol (DHCP);

means for monitoring Network Layer (Layer

     3) connectivity with a remote network device of a network; and

means for performing DHCP initialization of the network device in response to detecting a loss of said monitored Network Layer connectivity.