Which of the following statements about BFD Echo packets are true? (Choose two.)
A. The Echo packet format is not defined in BFD.
B. The Echo packet format is defined in BFD.
C. Echo packets use UDP destination port number 3785.
D. Echo packets use UDP destination port number 3784.
An OSPF neighbor relationship fails to be established and the display ospf error command output is as follows.Which of the following is the possible cause?
A. Router IDs conflict.
B. Area IDs are mismatched.
C. Network masks are inconsistent.
D. Authentication passwords are inconsistent.
ABRs of a Stub area do not flood Type-5 and Type-4 LSAs to the Stub area. Therefore, the Stub area does not have the external AS routing capability. ABRs of the Stub area advertise a default route to the stub area to guide packet forwarding to the external of the AS.
Assume that the subnet mask is 255.255.255.248. Which of the following addresses are valid host addresses? (Choose three.)
Which of the following statements is false?
A. An ABR maintains an LSDB for each area. There are many LSDBs on an ABR.
B. The metric of an ASE LSA can be specified when an external route is imported. The default value is 1.
C. The external routing information carries a Tag label for transmitting additional information of the route. It is commonly used in a routing policy. The default value of the Tag label is 0.
D. The Link State ID in an ASBR-Summary-LSA is the Router ID of the ASBR.
If the Router Priority of a router is set to 0, this router cannot be elected as a DR or a BDR.
Only Router-LSAs and Network-LSAs are involved in intra-area route calculations.
Which of the following statements about Flush packets in a Smart Link group are true? (Choose three.)
A. A Smart Link group sends Flush packets to instruct other devices to update the address table.
B. Flush packets use IEEE 802.3 encapsulation.
C. The destination MAC address of Flush packets is an unknown unicast address, which is used to distinguish protocols.
D. The destination MAC address of Flush packets is a special multicast address, which is used to distinguish protocols.
Which of the following statements about Stub areas is false?
A. The difference between a Stub area and a Totally Stubby area is that the Totally Stubby area cannot contain summary-LSAs.
B. The ABR in the Stub area generates a default route to guide forwarding of packets destined for other area.
C. A Transit area cannot be configured as a Stub area.
D. Any Stub area can be configured as a Totally Stubby area.
Each router running OSPF has a router ID. A router ID is a 32-bit integer and uniquely identifies a router. Hence, even of routers in different ASs, the router IDs must be different.