BGP Hard Reset vs Soft Reset

Difference between BGP Hard Reset and Soft Reset:

PARAMETER	HARD RESET	SOFT RESET
Philosophy	This will tear down the TCP connection between the peers and re-establish the connection with a BGP Open message and proceed with the regular message exchanges between peers.	Soft reset is of 2 types – (1) Soft reset with Route refresh (2) soft-reconfiguration. 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.
Direction	Both in and out	In or Out
Impact	Severely disrupts reachability for all networks	Impacts only those prefixes affected by policy change
Usage	Should be used as last resort when soft reset is not able to address the issue.	Preferred approach.
Memory usage	No additional memory requirement for storing another table.	Requires additional memory since Router now stores another table for each neighbor instead of one BGP table
Convergence time	Very long since Processing of the full Internet table can take a really long time.	Much shorter than hard reset
Prerequisite	No	Both peers may be required to support the Route Refresh capability (for Soft reset with Route refresh feature)
Related commands	clear ip bgp {* \| neighbor ip \| peer-group}	clear ip bgp {neighbor ip} soft out clear ip bgp {neighbor ip} soft in