How long is the default GR period of the OSPF routing protocol used by S series switches


For S series switches supporting OSPF, the default graceful restart (GR) period of the OSPF routing protocol is 120 seconds. If an OSPF neighbor relationship does not enter the Full state within 120 seconds, the GR fails. For example, when there are a large number of OSPF link-state advertisements (LSAs), LSA synchronization may not be complete within the default GR period, causing the GR to fail. In this case, run the graceful-restart period period command in the OSPF view to change the GR period on the Restarter.

Other related questions:
What is the default STP mode for S series switches
For S (except the S1700) and E series switches, STP works in MSTP mode by default.

S series switches routing protocol priority problem
default: - Direct�? - OSPF�?0 - IS-IS�?5 - Static�?0 - RIP�?00 - OSPF ASE�?50 - OSPF NSSA�?50 - IBGP�?55 - EBGP�?55

What is the protocol number of OSPF used by S series switches
The Open Shortest Path First (OSPF) protocol is a link-state Interior Gateway Protocol (IGP) developed by the Internet Engineering Task Force (IETF). OSPF is IP-based and the protocol number is 89.

Configure the priority of an OSPF route on an S series switch
The routing protocols may share and select the routing information because a switch may run multiple dynamic routing protocols simultaneously. In this case, a priority should be set for each routing protocol. When different protocols find multiple routes to the same destination, the route discovered by the protocol with a higher priority is preferred. On an S series switch, you can run the preference command in the OSPF process view to configure the OSPF priority. Perform the following operations: 1. Run the ospf [ process-id ] command in the system view to enter the OSPF process view. 2. Run the preference [ ase ] { preference | route-policy route-policy-name } * command to configure the OSPF priority. The parameters are described as follows: ase: indicates the priority of the AS-External route. preference: indicates the OSPF route priority. A smaller value indicates a higher priority. route-policy route-policy-name: indicates the priority for specified routes in the routing policy. The default OSPF priority value is 10. When an ASE is specified, the default OSPF priority is 150. For example, set the priority of routes in OSPF process 100 to 150 as follows: [HUAWEI] ospf 100 [HUAWEI-ospf-100] preference 150

How do S series switches implement unplanned OSPF GR and planned OSPF GR
In unplanned GR mode, a device directly performs a active/standby switchover without sending a grace LSA to its peer. As a result, the peer does not enter the Helper state. After the standby card switches to the active card and goes Up, the device sends a grace LSA. Therefore, the smooth time cannot exceed the dead interval. The timer in graceful period timer of IETF GR needs to be negotiated based on the timer value configured on the Restarter. The default timer value is 120s.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top