Advanced IP Network Design (CCIE Professional Development)

BGP Network Growing Pains

Even BGP may experience some growing pains as the core or the regions grow. Keep in mind that a full iBGP mesh is required. Most likely, the core will have a pervasive BGP configuration (which means that all the routers run BGP). Some of the issues that need to be kept in mind with a large number of neighbors include the following:

• BGP update generation

• Loss of information due to aggregation

• Scaling BGP policies

• Scaling IBGP mesh

• Route flaps

Update Generation Issues

BGP sends only incremental updates. If the network is stable, why is update generation a problem? One update needs to be formed for every peer. In other words, each time a prefix changes, the router needs to generate the same amount of updates as neighbors ...