In BGP terminology, administrators may be required to reset BGP peers .One instance where resetting is required in when inbound filtering is applied on BGP speaking router so as to apply filtering on the received Update message.
There are two ways to reset a peer – Hard Reset and Soft Reset.
While Hard Reset kills the TCP session with BGP neighbor forcing it to restart. This process disrupts the network and considered last resort if soft reset fails.
Soft Refresh can be of 2 types –
(1) Soft reset with Route refresh
Soft Refresh with Route Refresh allows BGP peers to request an update without tearing down the entire neighbor relationship.In Soft-reconfiguration option, since a route-refresh request is not sent to BGP neighbor, a copy is stored of BGP routes delivered in the BGP update from our peer.
Below table details on difference between Hard Reset and Soft Reset in BGP –