3Com Switch 8800 Advanced Software V5 Configuration Guide

Introduction to OSPF 319
Figure 102 NSSA external LSA format
Supported OSPF
Features
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.
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.
Hot Standby and GR
Distributed routers support OSPF Hot Standby (HSB). OSPF backups necessary
information of the active fabric into the standby fabric. Once the active fabric fails,
the standby fabric begins to work to ensure the normal operation of OSPF.
OSPF supports to backup:
■ All OSPF data to the standby fabric to make sure OSPF recovers normal
operation immediately upon the main fabric failure.
■ Only the OSPF configuration information to the standby fabric. Once the main
fabric 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.
Network mask
Forwarding address
LS age
Linke state ID
Advertising Router
Options 7
LS sequence number
LS checksum Length
Metric
External route tag
...
E TOS
0715 31