Which two statements regarding the IS-IS DIS election process are true? (Choose two.)

A.
L1 routers on a broadcast network only establish adjacencies with the DIS.

B.
If the DIS becomes unavailable the backup DIS is promoted to DIS.

C.
Adding a router with a higher priority than the current DIS will result in the new router becoming
DIS.

D.
Separate L1 and L2 election processes are held on a brodcast network.

E.
A priority of 0 will prevent a router from becoming a DIS.

F.
If there is a tie based on priority, the router whose attached interface has the lowest MAC
address becomes the DIS.

Explanation:
Election of the DIS
On a LAN, one of the routers elects itself the DIS, based on interface priority (the default is 64). If
all interface priorities are the same, the router with the highest subnetwork point of attachment
(SNPA) is selected. The SNPA is the MAC address on a LAN, and the local data link connection
identifier (DLCI) on a Frame Relay network. If the SNPA is a DLCI and is the same at both sides of
a link, the router with the higher system ID becomes the DIS. Every IS-IS router interface is
assigned both a L1 priority and a L2 priority in the range from 0 to 127.
The DIS election is preemptive (unlike OSPF). If a new router boots on the LAN with a higher
interface priority, the new router becomes the DIS. It purges the old pseudonode LSP and floods a
new set of LSPs.