Which one of the following potential issues is eliminated by using split horizon？（）

For the following items，what is the mathematical relationship between the committed information  rate （CIR）， committed burst （Bc）， and committed rate measurement interval （Tc）？（）

You are the network administrator of a Layer 3 switched network. Users in one VLAN are complaining that access to the server VLAN is very slow from time to time. Traffic in the local VLAN works without any issue， and users in other VLANs do not have any complaint to reach the server VLAN. What is most likely the cause of this issue？（）

Two directly connected routers， R1 and R2， are both configured for OSPF graceful restart. R2 is able to switch packets in hardware， but R1 is not. If a network administrator logs on to R2 and performs a system reload， which will be the result？（）

Which three are needed to run VRF lite for IPv6 on a router？ （）

IEEE 802.1w is a Rapid Spanning Tree Protocol （RSTP） that can be seen as an evolution of the 802.1 standard. What are the port roles described by 802.1w？（）

In which way can the IPv6 address of 2031：0000：130F：0000：0000：09C0：876A：130B be expressed most efficiently？（）

When two bridges are competing for the root bridge of an IEEE 802.1D spanning tree and both have the same bridge priority configured， which parameter determines the winner？（）

When a BGP router is not capable of understanding 4-byte AS numbers， it will see 4-byte AS numbers as a special， reserved， 2-byte AS number in the AS path. Which 2-byte AS number is this reserved one？（）

What does a unicast prefix-based IPv6 multicast address start with？（）