Browse Prior Art Database

ROUTING INFORMATION PROTOCOL WITH BACKUP ROUTER RECOVERY

IP.com Disclosure Number: IPCOM000008356D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-10
Document File: 2 page(s) / 105K

Publishing Venue

Motorola

Related People

Reyhan Yucebay: AUTHOR

Abstract

In Routing Information Protocol (RIP), a router broadcasts its routes every thirty seconds. If a router is not refreshed within 180 seconds, a router is declared failed, and the distance is set to infinity, and distance vector algorithm is performed to find a new route to that destination. Waiting 180 seconds to decide a router unoperational has a negative effect on network robustness, especially in wireless net- works that are very sensitive to transmission delays. Furthermore, during this network convergence rout- ing tables may include infinitive loops. Bouncing packets between loops increase large amount of packet loses and the congestion of the network.

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MO-LA Technical Developments

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ROUTING INFORMATION PROTOCOL WITH BACKUP ROUTER RECOVERY

by Reyhan Yucebay

  In Routing Information Protocol (RIP), a router broadcasts its routes every thirty seconds. If a router is not refreshed within 180 seconds, a router is declared failed, and the distance is set to infinity, and distance vector algorithm is performed to find a new route to that destination. Waiting 180 seconds to decide a router unoperational has a negative effect on network robustness, especially in wireless net- works that are very sensitive to transmission delays. Furthermore, during this network convergence rout- ing tables may include infinitive loops. Bouncing packets between loops increase large amount of

packet loses and the congestion of the network.

  The proposed solution to this problem is having a backup router for a backbone network router. A backbone router is considered as a primary router, and it is backed up with a secondary router called "backup" router. A backup router checks regularly if the primary router is operational. If the primary router does not respond within a configurable time interval, backup router takes over, and it starts advertising the reachability of the primary router's network.

192.9.122.10

Fig. 1 Network ConIigured with Primary and Backup Routers

  In Figure 1, PRl and PR2 are backbone routers A backup router periodically sends a query serving networks N3 and, N2. BKUP/A is a packet to its primary router and maintains its routing secondary router for network N3, and BKUP/B is a tables through RIP request and response messages. secondary router for network N2. When BKUP/A A backup router is a silent node. It listens to other finds out that PRl is dead, it starts advertising N3 to routers to maintain its own routing table. A primary routers R2, R4, and R3. router listens on a designated socket and responds

a MOfOroIa. 1°C. ,997 188 September 1997

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0 M MO-LA

Technical Developments

to backup router query within a configurable interval. The interval time for an alive message depends on the topology and the condition of a network. The configurable interval should b...