What does the EIGRP stuck in active message mean?
- When EIGRP returns a stuck in active (SIA) message, it means that it has not received a reply to a query. An EIGRP neighbour (or neighbours) have not replied to the query for that route.
- When the SIA occurs, the router clears the neighbour that did not reply to the query.
Why do you not see OSPF neighbours as FULL/DR or FULL/BDR on serial link?
This is normal. On point-to-point and point-to-multipoint networks, there are no designated routers (DRs) or backup designated routers (BDRs).
What is multicast address for EIGRP and OSPF hello packets:
- EIGRP – 22.214.171.124
- OSPF – for all the routers – 126.96.36.199
- OSPF – initial multicast – only for DR and BDR – 188.8.131.52
What is type-1 and type-2 LSAs in OSPF?
- Type-1 LSAs are router LSAs and are generated by each router for the area to which the router belongs.
- Type-2 LSAs are network LSAs and are generated by the DR and BDR.
OSPF network types:
- Broadcast, multi-access networks: Ehternet, token ring. Single mode operation.
- Point-to-point : T1 CAS, ISDN BRI/PRI, single operation mode, no DR/BDR.
- Non-broadcast multi-access(NBMA) networks: Frame realy, ATM, MPLS. Five modes of operation.