Intermediate System to Intermediate System (IS-IS) Hitless Reboot with Redistributed Routes
AssigneeArista Networks, Inc.
InventorNikhil GOYAL
Life of this patent
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Abstract
Techniques are provided for implementing hitless reboot on a network device that runs Intermediate System to Intermediate System (IS-IS) protocol in conjunction with one or more other routing protocols and has route redistribution enabled for redistributing routes learned via the one or more other routing protocols into IS-IS. In certain embodiments, these techniques modify the restart processing performed by the network device to ensure that its IS-IS neighbors correctly maintain the redistributed routes it received from the device via IS-IS prior to the hitless reboot.
Claims19
A method performed by a network device that runs Intermediate System to Intermediate System (IS-IS) protocol, the method comprising, at the time of booting up a control plane of the network device as part of a hitless reboot:
- receiving one or more link-state packets (LSPs) from one or more neighbor devices;
- updating a link-state database (LSDB) based on the one or more LSPs;
- generating a post-restart LSP based on contents of the LSDB;
- waiting for one or more signals indicating that one or more other routing protocols running on the network device have converged;
- and
- upon receiving or detecting the one or more signals:
- updating the post-restart LSP based on latest contents of the LSDB;
- and
- advertising the updated post-restart LSP to the one or more neighbor devices.
The method of claim 2 wherein the latest contents of the LSDB include one or more routes redistributed from the first routing protocol to the IS-IS protocol.
- The method of claim 3 wherein the updated post-restart LSP includes the one or more routes.
The method of claim 4 wherein, prior to receiving or detecting the one or more signals, the generated post-restart LSP does not include the one or more routes.
A network device comprising:
- a data plane;
- and
- a control plane including a central processing unit (CPU) and a main memory, the main memory having stored thereon program code that when executed by the CPU causes the CPU to, at a time of booting up the control plane as part of a hitless reboot:
- receive one or more link-state packets (LSPs) from one or more neighbor devices;
- update a link-state database (LSDB) based on the one or more LSPs;
- generate a post-restart LSP based on contents of the LSDB;
- wait for one or more signals indicating that one or more other routing protocols running on the network device have converged;
- and
- upon receiving or detecting the one or more signals:
- update the post-restart LSP based on latest contents of the LSDB;
- and
- advertise the updated post-restart LSP to the one or more neighbor devices.
A method performed by a network device that runs Intermediate System to Intermediate System (IS-IS) protocol and another routing protocol different from the IS-IS protocol, the method comprising, at the time of booting up a control plane of the network device as part of a hitless reboot:
- generating a post-restart LSP based on contents of a link-state database (LSDB);
- and
- refraining from advertising the post-restart LSP to one or more IS-IS neighbor devices of the network device until the network device has received or detected a signal indicating that said another routing protocol has converged,
- wherein route redistribution from said another routing protocol to the IS-IS protocol is enabled on the network device.
Dependencies are inferred from the claim text.