Stackable routers employing a routing protocol
US7916757B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2008 |
| Grant date | Mar 29, 2011 |
| Priority date | — |
| Expiry date | Dec 17, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/583
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A stack of network routers is composed of at least one (elected) master unit and one or more slave units each capable of running a routing protocol. Only the master unit runs the entire routing protocol at a given time. It forwards direct update messages via a transmission control protocol to each of the slave units. These direct update messages may include specific packet formats for the protocol state machinery where such machinery is required by the routing protocol, e.g., the interface state machine and the neighbor state machine for the OSPF protocol, and for the net databases, e.g. the link state databases for the OSPF protocol, in each of the slave units. Each slave unit may run its protocol state machinery (where provided) based purely on the direct update messages received from the master. The synchronisation of the net databases may be based on snooping net update packets and a comparison of the information received thereby with verification data messages sent from the master unit. The synchronization allows the running of the routing protocol on multiple physical routers in a stack without requiring the overhead of a back-up unit that would not perform routing unless a m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.