Which common issue causes intermittent DMVPN tunnel flaps?

Which two commands must you configure in the calling router to support the PPPoE client? (Choose two.)

Refer to the exhibit.

Which option prevents routing updates from being sent to the DHCP router, while still allowing routing update messages to flow to the Internet router and the distribution switches?

something received by a BGP router from another internal BGP router to prevent bgp routing loop ?

OSPF
HH010.com is a small IT corporation that is attempting to implement the network shown in the exhibit. Currently the implementation is partially completed. OSPF has been configured on routers Chicago and NewYork. The SO/O interface on Chicago and the SO/1 interface on NewYork are in Area 0. The loopbackO interface on NewYork is in Area 1.
However, they cannot ping from the serial interface of the Seattle router to the loopback interface of the NewYork router. You have been asked to complete the implementation to allow this ping.
HH010.com's corporate implementation guidelines require:
* The OSPF process ID for all routers must be 10.
* The routing protocol for each interface must be enabled under the routing process.
* The routing protocol must be enabled for each interface using the most specific wildcard mask possible.
* The serial link between Seattle and Chicago must be in OSPF area 21.
* OSPF area 21 must not receive any inter-area or external routes.(except the default route)
Network Information
Seattle
S0/0 192.168.16.5/30 -Link between Seattle and Chicago Secret Password: cisco
Chicago
S0/0 192.168.54.9/30 -Link between Chicago and NewYork
S0/1 192.168.16.6/30 -Link between Seattle and Chicago Secre
Password: cisco
NewYork
S0/1 192.168.54.10/30 -Link between Chicago and NewYork
Loopback0 172.16.189.189
Secret Password: cisco