There are times when route propagated in BGP doesn't exist. As we know that even in link down situation, BGP takes its own sweet time to converge. In this kind of scenario we need to clear advertised routes and in some cases we use the following command
clear ip bgp *
You can also verify the advertised routes with following command
sh ip bgp neighbors A.B.C.D advertised-routes
Even in cases when you change the inbound/outbound policy , you need to reset your BGP session.But using clear ip bgp * can impact all other links as BGP will create routing table from scratch. This is as good as rebooting the router. To minimise impact we can use following command.
clear ip bgp A.B.C.D soft out –> When you make changes in outbound policy
clear ip bgp A.B.C.D soft in –> When you make changes in inbound policy .