What is graceful restart in BGP?

A new BGP capability, termed “Graceful Restart Capability”, is defined that would allow a BGP speaker to express its ability to preserve forwarding state during BGP restart. Finally, procedures are outlined for temporarily retaining routing information across a TCP session termination/re-establishment.

How do I enable BGP graceful restart?

To enable the BGP long-lived graceful restart (LLGR) capability, include the long-lived receiver enable statement at the [edit protocols bgp graceful-restart] hierarchy level.

How do you test BGP graceful restart?

To verify proper operation of graceful restart, use the following commands:

1. show bgp neighbor (for BGP graceful restart)
2. show log (for IS-IS and OSPF/OSPFv3 graceful restart)
3. show (ospf | ospfv3) overview (for OSPF/OSPFv3 graceful restart)
4. show rsvp neighbor detail (for RSVP graceful restart—helper router)

What is BGP hold time?

three seconds
The Hold Time is a heartbeat mechanism for BGP neighbors to ensure that the neighbor is healthy and alive. When establishing a BGP session, the routers use the smaller Hold Time value contained in the two router’s OPEN messages. The Hold Time value must be at least three seconds, or zero.

Which two requirements must be satisfied before graceful restart will work?

Correct Answer: AB

• a stable network topology.
• a neighbor configured with BFD.
• a neighbor configured with graceful restart.
• a neighbor with an uptime greater than an hour.

What is LDP graceful restart?

MPLS LDP graceful restart is an LDP protocol feature that, in the presence of a temporary LDP control plane disruption, preserves Nonstop Forwarding (NSF) support of data plane traffic being carried on label-switched paths (LSPs).

What is OSPF NSF?

Information About OSPF NSF Awareness The OSPF Nonstop Forwarding (NSF) Awareness feature allows customer premise equipment (CPE) routers that are NSF-aware to help NSF-capable routers perform nonstop forwarding of packets. The awareness feature is part of the software code; it need not be configured.

When and how should I reset a BGP session?

When BGP routing policy is changed (changing the attributes or adding filters) it is required to reset BGP session before the new policy takes effect. Soft reset is a recommended option to refresh the BGP routing table without disturbing existing BGP peering sessions. in: To refresh only received BGP routes.