H3C Technologies H3C SR8800 - Manual (Page 91)

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An AS external LSA is originated by an ASBR, describing routing information to a destination
outside the AS.
Figure 35 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. See “
Route types “ for descriptions of external
route types.
{
Metric—The metric to the destination.
{
Forwarding Addres—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.
• NSSA external LSA
An NSSA external LSA originates from the ASBR in a NSSA and is flooded in the NSSA area only.
It has the same format as the AS external LSA.