A.The ip subnet-zero command has been issued on the R1 router.
B.The RIPv2 dynamic routing protocol cannot be used across a Frame Relay network.
C.Split horizon is preventing R2 from learning about the R3 networks and R3 from learning about R2 networks.
D.The 172.16.2.0/25 and 172.16.2.128/25 networks are overlapping networks that can be seen by R1,but not between R2 and R3.
E.The 172.16.3.0/29 network used on the Frame Relay links is creating a discontiguous network between the R2 and R3 router subnetworks.

A.when a packet is received from an 802.1Q trunk,the vlan id can be determined from the source MAC address table
B.unkown unicast frames are retransmitted only to the ports that belong to the same vlan
C.ports between switches should be configured in access mode so that vlans can span across the ports
D.broadcast and multicast frames are retransmitted to ports that are configured on different vlan.

A.to provide routing to a local web server
B.to provide routing from an ISP to a stub network
C.to provide routing that will override the configured dynamic routing protocol
D.to provide routing to a destination that is not specified in the routing table and which is outside the local network

A.RIP requires less time to converge
B.RIP uses less bandwidth
C.RIP is less complex to configure
D.RIP demands fewer router resources
E.RIP has a more accurate metric

A.The denied MAC addresses have already been learned or confgured on another secure interface in the same VLAN.
B.The denied MAC address are statically configured on the port.
C.The minimum MAC threshold has been reached.
D.The absolute aging times for the denied MAC addresses have expired.

A.an OSPF update for network 192.168.0.0/16
B.a static router to network 192.168.10.0/24
C.a static router to network 192.168.10.0/24 with a local serial interface configured as the next hop
D.a RIP update for network 192.168.10.0/24
E.a directly connected interface with an address of 192.168.10.254/24
F.a default route with a next hop address of 192.168.10.1

A.session
B.network
C.physical
D.datalink
E.transport

A.Passive routes are in the process of being calculated by DUAL.
B.EIGRP supports VLSM，route summarization，and routing update authentication.
C.EIGRP exchanges full routing table information with neighboring routers with every update.
D.If the feasible successor has a higher advertised distance than the successor route，it becomes theprimary route.
E.A query process is used to discover a replacement for a failed route if a feasible successor is not identified from the current routing information.

A.Switch3
B.Switch4
C.Switch2
D.Switch1

A.172.16.16.0
B.172.16.24.0
C.172.16.0.0
D.172.16.28.0