H3C Technologies H3C S12500 Series Switches - Manual (Page 85)

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Figure 33 Network LSA format
Major fields of the Network LSA are as follows:
{
Link state ID—The interface address of the DR.
{
Network mask—The mask of the network (a broadcast or NBMA network).
{
Attached router—The IDs of the routers, which are adjacent to the DR, including the DR itself.
• Summary LSA
Network summary LSAs (Type-3 LSAs) and ASBR summary LSAs (Type-4 LSAs) are originated by
ABRs. Except for the Link state ID field, the formats of Type-3 and Type-4 summary LSAs are
identical.
Figure 34 Summary LSA format
Major fields of the Summary LSA are as follows:
{
Link state ID—For a Type-3 LSA, it is an IP address outside the area. For a Type-4 LSA, it is the
router ID of an ASBR outside the area.
{
Network mask—The network mask for the Type-3 LSA. It is set to 0.0.0.0 for the Type-4 LSA.
{
Metric—The metric to the destination.
NOTE:
A Type-3 LSA can be used to advertise a default route if the Link state ID and Network mask are set
to 0.0.0.0.
• AS external LSA