open shortest path first is a link state interior routing protocol used to flood topology information within an mpls core. topology info consists of loopback reachability and feaure parameters used within the domain. routers send periodic hello packet in order to discover each other. once a new router discovered, a master is elected and the database descriptors are sent out. only the missing lsas are requested, sent out and acknowldged. once the initial flood is over, just the changed lsas are sent when arrive from an other router. neighborships and internal prefixes are described in the router lsas, redistributed routes are described in the external lsas, and inter-area routes are described in the summary lsas. once the lsa database changed, a router calculates shortest path first, and fills it's routing table. on broadcast networks they elect a designated router and a backup dr. the elected dr lists it's peers on the lan in a network lsa, and peers describe theirselves to this network lsa advertised by the dr, not to each other. here are the captures for reachability, te, sr and bier.
look for the features within the area-opaque lsa in case of ospfv2 and e-router and e-prefix lsa in case of ospfv3.