| 摘要 |
<p>High availability BGP4 is based on redundant hardware as well as redundant software that replicates the RUN state of BGP4. There are two copies, respectively active 11 and backup 12, of BGP4 running on two separate redundant hardware platforms. All BGP4 internal implementations apply various methods to replicate the running state of BGP4 independently of peer network routers 14, 15, 16. When this hardware or software fails 302, 304 on one redundant hardware platform, peer routers are unaware of the failure. Internally, based on duplicative states, the local router 10 recovers 303, 305 from the failure and keeps the protocol running. During the recovery period, the local router can bring up a backup 12 again. In the HA architecture, these activities are not detected by peer routers, such that there is no instability to the Internet backbone caused by BGP4 failure. <IMAGE></p> |
