User's Manual

46-12
information and enable selection deferral timer.
5. R1 delays the count process of the local BGP route until it receives all End-of-RIB from BGP neighbors in
GR-Aware or until the local selection deferral timer is overtime.
6. Count route and send the update route. After that, it will send End-of-RIB to neighbors.
Restarting Speaker（GR-Helper）:
1. R1 and R2 negotiate GR capability with the restarted router when they establish the original neighborhood
with BGP, R1 is a router that support GR-Capable.
2. When R1 is restarted, R2 may senses that TCP between R1 and R2 is cut off or cannot detect the previous
state before they establish TCP connection again. If it does not detect it, go to step 4, otherwise go to step 3.
3. Keep the route sent by R1 and mark a stale label. After that, enable Restart Timer.
4. Cut off old TCP connection and deal with new TCP connection continuously. Keep the route sent by R1 and
mark a stale label. After that, enable Restart Timer.
5. Establish a new neighborhood with the restarted router, delete Restart Timer and enable Stale Path Timer.
6. Before establish the new neighborhood, If Restart Timer is overtime, Restart flag does not equal 1, or there
is no relevant supporting information in AFI/SAFI address family, please clear the kept route.
7. Send the route update information to the restarted router, after that, it will send End-Of-RIB label.
8. If Stale Path Timer is overtime, clear the kept route.
46.2 GR Configuration Task List
1. Configure whether GR capability is supported
2. Configure whether the specific neighbor supports GR capability
3. Configure restart-time
4. Configure restart-time for neighbor
5. Configure stale-path-time for BGP GR
6. Configure selection-deferral-time for BGP GR
1. Configure whether GR capability is supported
Command
Explanation
BGP route configuration mode
bgp graceful-restart
no bgp graceful-restart
Enable BGP to support GR.