H3C S3610-28P Operation Manual page 387

Operation Manual – IPv4 Routing
H3C S3610&S5510 Series Ethernet Switches
Note:
A Type-3 LSA can be used to advertise a default route, having the Link State ID and
Network Mask set to 0.0.0.0.
4) AS external LSA
An AS external LSA originates from an ASBR, describing routing information to a
destination outside the AS.
Figure 3-19 AS external LSA format
Major fields:
Link State ID: The IP address of another AS to be advertised. When describing a
default route, the Link State ID is always set to Default Destination (0.0.0.0) and
the Network Mask is set to 0.0.0.0
Network Mask: The IP address mask for the advertised destination
E (External Metric): The type of the external metric value, which is set to 1 for type
2 external routes, and set to 0 for type 1 external routes. Refer to
description about external route types
metric: The metric to the destination
Forwarding Address: Data traffic for the advertised destination will be forwarded to
this address
External Route Tag: A tag attached to each external route. This is not used by the
OSPF protocol itself. It may be used to manage external routes.
5) NSSA external LSA
3-19
Chapter 3 OSPF Configuration
Route types for