A. Loop guard can be used with root guard simultaneously on the same port on the same VLAN while UDLD cannot
B. UDLD protects against STP failures caused by cabling problems that create one-way links.
C. Loop guard detects and protects against duplicate packets being received and transmitted on different ports
D. UDLD protects against unidirectional cabling problems on copper and fiber media.
E. Loop guard protects against STP failures caused by problems that result in the loss of BPDUs from a designated switch port.

A.followers field
B.MD5 digest
C.VLAN information
D.sequence number

A. GE-3/1， GE-3/2
B. FE-2/1， FE-3/2
C. GE-1/1， GE-1/2
D. GE-4/1， GE-4/2
E. GE-2/1， GE-2/2
F. GE-3/1， GE-3/2， GE-4/1， GE-4/2， FE-2/1， FE-3/2

A.runts
B.FCS errors
C.interface resets
D.late collisions

A.mpls ip cef
B.port-channel ip cef
C.mpls ip port-channel cef
D.port-channel load balance
E.mpls ip load-balance
F.ip cef EtherChannel channel-id XOR L4
G.ip cef connection exchange

A. GE-1/2 and GE 2/1
B. GE-1/1 and GE-2/2
C. GE-3/2 and GE 4/1
D. no ports are in the blocking state
E. There is not enough information to determine which ports are in the blocking state.

A.The originator of the TCN immediately floods this information through the network.
B.The TCN propagation is a two step process.
C.A TCN is generated and sent to the root bridge.
D.The root bridge must flood this information throughout the network.

A. Increase the root bridge priority （increasing the numerical priority number） for VLAN 2 on Catalyst D so that port D2 becomes the root port on Catalyst D for VLAN 2.
B. Decrease the port priority on R2 for VLAN 2 on Catalyst R so that port D1 will be blocked for VLAN 2 and port D2 will remain blocked for VLAN 1.
C. Decrease the path cost on R2 on Catalyst R for VLAN 2 so that port D1 will be blocked for VLAN 2 and port D2 will remain blocked for VLAN 1.
D. Increase the root bridge priority （decreasing the numerical priority number） for VLAN 2 on Catalyst R so that R2 becomes the root port on Catalyst D for VLAN 2.

A.Loop guard only operates on interfaces that are considered point-to-point by the spanning tree.
B.Loop guard only operates on root ports.
C.Loop guard only operates on designated ports.
D.Loop guard only operates on edge ports.

A.It may allocate IP addresses from an unknown subnet to the users.
B.All multicast traffic can be sniffed by using the DHCP multicast capabilities.
C.The CPU utilization of the first hop router can be overloaded by exploiting DHCP relay open ports.
D.A potential man-in-the-middle attack can be used against the clients.