QTECH
Software Configuration Manual
8-109
NSSA external LSA format
8.1.6
Supported OSPF Features
8.1.6.1 Multi-process
With multi-process support, multiple OSPF processes can run on a router simultaneously and independently.
Routing information interactions between different processes seem like interactions between different routing
protocols. Multiple OSPF processes can use the same RID.
An interface of a router can only belong to a single OSPF process.
8.1.6.2 Authentication
OSPF supports authentication on packets. Only packets that pass the authentication are received. If hello
packets cannot pass authentication, no neighbor relationship can be established.
The authentication type for interfaces attached to a single area must be identical. Authentication types
include non-authentication, plaintext authentication and MD5 ciphertext authentication. The authentication password
for interfaces attached to a network segment must be identical.
8.1.6.3 Hot Standby and GR
Distributed routers support OSPF Hot Standby (HSB). OSPF backs up necessary information of the Active
Main Board (AMB) into the Standby Main Board. Once the AMB fails, the SMB begins to work to ensure the normal
operation of OSPF.
OSPF supports to backup :
·
All OSPF data to the SMB to make sure OSPF recovers normal operation immediately upon the AMB
failure.
·
Only the OSPF configuration information to the SMB. Once the AMB fails, OSPF will perform Graceful
Restart (GR), obtaining adjacencies from and synchronizing the Link State Database with neighbors.
The Graceful Restart of the router is mainly used for High Availability (HA) and will not interfere with any
other routers.
When a router shuts down, its neighbors will delete it from their neighbor tables and inform other routers,
resulting in SPF recalculation. If the router restarts in several seconds, it is unnecessary to perform SPF recalculation,
and reestablish adjacencies.