What is the primary mechanism that prevents BGP routing loops?

What are two types of valid BGP messages? (Choose two.)

Your network is configured with a full mesh of MPLS LSPs between all devices. However, when
you enter the show route table inet.2 command on any device, no LSP routing information is
displayed.
Which statement explains why this is occurring?

You are experiencing packet drops in your network.
Which two CoS components would be responsible? (Choose two.)

Your Junos device has the following IS-IS configuration:
[edit protocols isis]
user@router# show
level 1 disable;
interface ge-0/0/0 {
level 2 disable;

}
Which statement is true?

In your network, you have noticed route oscillation involving an OSPF route.
What is the reason?

You notice that an EBGP peering session has terminated and no NOTIFICATION message
appears in the traceoptions output.
What has happened?

R2 has an IBGP peering session with R1 but is not installing the expected external BGP routes.
R1 has these same routes installed and they are active in its route table.
What are two reasons for this happening? (Choose two.)

You have enabled MPLS in your network using LDP for control plane signaling. After completing
the configurations, you find that both your input and output LDP databases have labels only for
loopback interfaces.
Referring to the scenario, which two statements are correct? (Choose two.)

You have configured an MPLS LSP but it will not establish because of a failed CSPF computation.
What are two reasons for this happening? (Choose two.)