NLSR no longer uses a combined sequence number as 1523 has been merged.
It uses a separate sequence number for each type of LSA.
Combined Sequence Number¶
The sequence numbers for each LSA type are combined and synced as one 64-bit sequence number.
The Name LSA sequence number is represented by a 24-bit value.
The Adjacency LSA and Coordinate LSA sequence numbers are represented by 20-bit values.
The sequence numbers are combined as follows:
Combined sequence number = (Name LSA SeqNo << 40) | (Coordinate LSA SeqNo << 20) | (Adjacency LSA SeqNo)