There are two similar features in BGP, “Route Refresh” and “graceful restart”. Can someone explain the difference between these two ?
Hello Abhishek
First of all, you can take a look at the following lesson:
and the following Cisco documentation:
Those are for your reference.
When the route refresh capability is enabled, when you change your BGP policy, the router will send a message its BGP neighbor requesting that it resends all of its prefixes. This results in no disruption at all.
The graceful restart feature of BGP essentially allows a BGP “speaker” to preserve the forwarding state during a BGP restart. In order for this to happen, BGP neighbours must have already communicated with each other and have informed each other of their Graceful Restart capability. If both are capable, then they can maintain their forwarding state even during a BGP restart.
So the difference is that a route refresh doesn’t involve a BGP restart, but simply a change in the BGP policy that requires an immediate refreshing of routes, while graceful restart actually involves a restart during which forwarding is not disrupted, but continues during the restart.
I hope this has been helpful!
Laz
Thanks for the help. It answers the query.