Black hole filtering

Patent metadata

Field	Value
Publication number	US-11425016-B2
Application number	US-201816049698-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Jul 30, 2018
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A system related to black hole filtering is provided. The system can allow a dynamic routing protocol on a network device to determine whether a route learned by the dynamic routing protocol is a black hole route. The route may be learned through another source. In response to a determination that the route is the black hole route, the dynamic routing protocol may generate a routing update that indicates the route as the black hole route. The dynamic routing protocol may then advertise the routing update to each neighbor network device.

First claim

The invention claimed is:

1. A method comprising:
determining, by a dynamic routing protocol on a network device, whether a route entry stored in a local data structure corresponds to a black hole route based on a first indicator in the entry,
wherein the route entry is generated from information learned by the dynamic routing protocol through another source;
in response to a determination that the route entry corresponds to is the black hole route, generating, by the dynamic routing protocol at the network device, a route update advertisement that advertises a route of the route entry for the dynamic routing protocol, wherein the route update advertisement includes a second indicator that indicates the advertised route as the black hole route,
wherein an unused bit in an Autonomous System (AS) external Link State Advertisement (LSA) associated with an Open Shortest Path First (OSPF) protocol is modified to facilitate the second indicator; and
sending, by the dynamic routing protocol, the route update advertisement to a respective neighbor network device.

2. The method of claim 1 , wherein the source includes one or more of: a second routing protocol, a static route, and a directly connected route.

3. The method of claim 1 , wherein the data structure includes a routing table generated by the dynamic routing protocol.

4. The method of claim 3 , wherein the routing table is a Forwarding Information Base (FIB).

5. The method of claim 1 , wherein determining whether the route entry corresponds to the black hole route further comprises: reviewing the route entry for the route; wherein the first indicator is route type in the route entry.

6. The method of claim 1 , wherein the dynamic routing protocol is one or more of: Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP).

7. The method of claim 1 , wherein generating the route update advertisement further comprises modifying an Attribute Type Code field in a BGP update message to facilitate the second indicator.

8. A network device, comprising:
processing circuitry; a dynamic routing logic block to execute a dynamic routing protocol for the network device,
wherein the dynamic routing logic block comprises:
a determination logic block to determine whether a route entry stored in a local data structure corresponds to a black hole route based on a first indicator in the entry,
wherein the route entry is generated from information learned by the dynamic routing protocol through another source;
a generation logic block to, in response to a determination that the route corresponds to the black hole route, generate, at the network device, a route update advertisement that advertises a route of the route entry for the dynamic routing protocol, wherein the route update advertisement includes a second indicator that indicates the advertised route as the black hole route,
wherein an unused bit in an Autonomous System (AS) external Link State Advertisement (LSA) associated with an Open Shortest Path First (OSPF) protocol is modified to facilitate the second indicator; and
an advertisement logic block to advertise the route update advertisement 16 to a respective neighbor network device.

9. The network device of claim 8 , wherein the dynamic routing 2 protocol is one or more of: Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP).

10. The network device of claim 8 , wherein the data structure includes a routing table generated by the dynamic routing protocol.

11. The network device of claim 8 , wherein the determination logic block is further to: review the route entry for the route; wherein the first entry is a route type in the route entry.

12. The network device of claim 8 , wherein the source includes one or more of: a second routing protocol, a static route, and a directly connected route.

13. A non-transitory machine-readable storage medium storing instructions, which when executed by a processor causes the processor to:
determine, by a dynamic routing protocol on a network device, whether a route entry stored in a local data structure corresponds to a black hole route based on a first indicator in the entry,
wherein the route entry is generated from information learned by the dynamic routing protocol through another source;
in response to a determination that the route entry corresponds to the black hole route, generate, by the dynamic routing protocol at the network device, a route update advertisement that advertises a route of the route entry for the dynamic routing protocol, wherein the route update advertisement includes a second indicator that indicates the advertised route as the black hole route,
wherein an unused bit in an Autonomous System (AS) external Link State Advertisement (LSA) associated with an Open Shortest Path First (OSPF) protocol is modified to facilitate the second indicator; and
send, by the dynamic routing protocol, the route update advertisement to a respective neighbor network device.

14. The storage medium of claim 13 , wherein the instructions, which when executed by the processor causes the processor further to modify an Attribute Type Code field in a Border Gateway Protocol (BGP) update message to facilitate the second indicator.

15. The storage medium of claim 13 , wherein the data structure includes a routing table generated by the dynamic routing protocol.

16. The storage medium of claim 15 , wherein the routing table is a Forwarding Information Base (FIB).

17. The storage medium of claim 13 , wherein the instructions, which when executed by the processor causes the processor further to: review the route entry for the route; wherein the first indicator is a route type in the route entry.

18. The storage medium of claim 13 , wherein the source includes one or more of: a second routing protocol, a static route, and a directly connected route.

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Raj Anil
• Govindan Nair Anoop
• Ponnappan Srijith

Classifications

• H04L45/18

  Loop-free operations · CPC title

• H04L63/1458

  Denial of Service · CPC title

• H04L63/0227 Primary

  Filtering policies (mail message filtering H04L51/212) · CPC title

• H04L63/1441

  Countermeasures against malicious traffic (countermeasures against attacks on cryptographic mechanisms H04L9/002) · CPC title

• H04L41/06

  Management of faults, events, alarms or notifications · CPC title