Determining connectivity status for unnumbered inerfaces of a target network device

• US 20070192501A1
• Filed: 06/01/2006
• Published: 08/16/2007
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Kompella, Kireeti
• Granted Patent: US 8,117,301 B2
• Time in Patent Office: Days
• US Class Current: 709/230
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

Techniques are described for testing connectivity to unnumbered interfaces of a target device. For example, a software utility and protocol are described that allows an administrator to specify a logical offset that may be internally resolved by the target device to one of a plurality of unnumbered interfaces during the test. Similarly, the administrator may specify an offset that may be internally resolved by the source device to one of a plurality of unnumbered interfaces from which the connectivity test is to originate. The source device may send enhanced request packets and receive enhanced reply packets specifying the source unnumbered interface and the destination unnumbered interface between which connectivity is to be tested. In this manner, an administrator may test for connectivity of particular interfaces even where internet protocol (IP) addresses or other identifiers for the interfaces are not externally known.

Claims

1. A method comprising:

executing a software utility on a source device;

presenting with the software utility a user interface to receive input from a user at a source device, wherein the input identifies a target device and an offset, wherein the offset represents an index into one of a plurality of unnumbered network interfaces of the target device for receiving packets from a network; and

outputting from the source device with the software utility one or more packets to test connectivity from the source device to one of the plurality of unnumbered network interfaces of the target device,

wherein at least one of the packets specifies the offset and communicates the offset from the source device to the target device to request a connectivity test.

2. The method of claim 1, further comprising:

receiving the one or more packets at the target device;

resolving the offset to one of the plurality of unnumbered network interfaces of the target device to select a target unnumbered network interface for which the connectivity test is requested; and

outputting to the source device a reply packet from the selected target unnumbered network interface of the target device to test connectivity between the target unnumbered network interface and the source device.

3. The method of claim 1, wherein executing a software utility comprises executing one of a ping utility or a traceroute utility that has been extended to receive the offset from the user and send the offset to the destination device using a modified Internet Control Message Protocol (ICMP) echo request packet.

4. The method of claim 1, wherein presenting with the software utility a user interface comprises presenting the user interface to include an optional field for the user to enter the offset.

5. The method of claim 1, further comprising:

presenting the user interface to receive a second offset from the user, wherein the second offset represents an index into one of a plurality of unnumbered network interfaces associated with the source device;

resolving the second offset to one of the plurality of unnumbered network interfaces of the source device to select a source unnumbered network interface; and

outputting with the software utility the one or more packets from the selected source unnumbered network interface to test connectivity from the source unnumbered network interface to the target device.

6. The method of claim 5, wherein outputting with the software utility the one or more packets comprises:

generating a request packet that includes a first field specifying the offset representing an index into the plurality of unnumbered network interfaces of the target device, and a second field specifying the second offset representing an index into the plurality of unnumbered network interfaces of the target device;

outputting the request packet from the selected source unnumbered network interface of the source device to the target device when a connectivity status of the selected source unnumbered network interface indicates the selected source unnumbered network interface is operable.

7. The method of claim 6, when the connectivity status indicates the selected source unnumbered network interface is not operable, the method further comprising:

outputting the request packet from a user interface of the source device other than the selected source unnumbered network interface; and

displaying a message indicating that the selected source unnumbered network interface is not operable.

8. The method of claim 1, further comprising:

displaying an indication of success when a reply packet is received from the target device with no indication of failure;

displaying an indication of failure when a reply packet is received from the target device indicating failure; and

displaying an indication of connectivity failure when a reply packet is not received from the target device.

9. A method comprising:

receiving from a source device a request packet to initiate a connectivity test at a target device, wherein the request packet includes a field specifying an offset;

resolving the offset to one of the plurality of unnumbered network interfaces of the target device for receiving packets from a network to select a target unnumbered network interface for which the connectivity test is requested; and

outputting to the source device a reply packet from the selected target unnumbered network interface of the target device to test connectivity between the target unnumbered network interface and the source device.

10. The method of claim 9, wherein outputting to the source device a reply packet further comprises outputting the reply packet from the selected target unnumbered network interface of the target device when a connectivity status indicates the selected target unnumbered network interface is operable.

11. The method of claim 9, wherein outputting to the source device a reply packet further comprises outputting the reply packet from an interface other than the selected target unnumbered network interface when a connectivity status indicates the selected target unnumbered network interface is not operable, wherein the reply packet contains a message indicating that the selected target unnumbered network interface corresponding to the offset is not operable.

12. A source network device comprising:

a software utility executing on the source network device that presents a user interface to receive input from a user, wherein the input identifies a target device and an offset that represents an index into one of a plurality of unnumbered network interfaces of the target device for receiving packets from a network; and

wherein the software utility outputs from the source network device one or more packets to test connectivity from the source network device to one of the plurality of unnumbered network interfaces of the target device.

13. The source network device of claim 12, wherein the software utility comprises one of a ping utility and a traceroute utility that has been extended to receive the offset from the user and send the offset to the destination device using a modified Internet Control Message Protocol (ICMP) echo request packet.

14. The source network device of claim 12, wherein the software utility presents a user interface that includes an optional field for the user to enter the offset.

15. The source network device of claim 12,

wherein the software utility presents the user interface to receive a second offset from the user, wherein the second offset represents an index into one of a plurality of unnumbered network interfaces associated with the source network device,

wherein the software utility resolves the second offset to one of the plurality of unnumbered network interfaces of the source network device to select a source unnumbered network interface, and

wherein the software utility outputs one or more packets from the selected source unnumbered network interface to test connectivity from the source unnumbered network interface to the target device.

16. A system comprising:

a source device that outputs a request packet to initiate a connectivity test at a target device, wherein the request packet includes a field specifying an offset; and

a target device that resolves the offset to one of a plurality of unnumbered network interfaces of the target device for receiving packets from a network to select a target unnumbered network interface for which the connectivity test is requested,

wherein the target device outputs to the source device a reply packet from the selected target unnumbered network interface of the target device to test connectivity between the target unnumbered network interface and the source device.

17. The system of claim 16,

wherein the source device provides an operating environment for a software utility that presents a user interface to receive input identifying the target device and specifying the offset, and

wherein the software utility outputs the request packet using a modified Internet Control Message Protocol (ICMP) echo request packet.

18. A computer-readable medium comprising instructions for causing a programmable processor to:

execute a software utility on a source device;

present with the software utility a user interface to receive input from a user at a source device, wherein the input identifies a target device and an offset, wherein the offset represents an index into one of a plurality of unnumbered network interfaces of the target device for receiving packets from a network; and

output from the source device with the software utility one or more packets to test connectivity from the source device to one of the plurality of unnumbered network interfaces of the target device,

wherein at least one of the packets specifies the offset and communicates the offset from the source device to the target device to request a connectivity test.