What is the STP root guard feature designed to prevent？（）

Multicast is being deployed in the network， and only ip pim sparse-dense mode has been configured on all interfaces in the network to support a new video streaming application. No other multicast configuration was applied anywhere in the network. Since enabling multicast， the network monitoring tools show periodic spikes in link utilization throughout the network， even in areas where the video application is not being used. What could be a possible cause？（）

Which switch port error is an indication of duplex mismatches on 10/100/1000 IEEE 802.3u  Gigabit Ethernet ports？（）

Internet Protocol version 6 （IPv6） is the next-generation Internet Layer protocol for packet-switched internetworks and the Internet. IPv6 router solicitation is（）

An administrator of a peer-to-peer server application reports that the maximum bandwidth that his application receives is 90 Mb/s. You have an 8-port，100-Mb/s EtherChannel bundle on the switching infrastructure between the two servers， resulting in a bidirectional throughput of more than what is recorded. Which two solutions would allow for more bandwidth for the application？（）

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？（）

In GLBP， which router will answer on client ARP requests？（）

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？（）

What are the "bound IP addresses" used for in LDP？（）

You are the network administrator of an enterprise company that just deployed a global IP telephony environment. In order to guarantee good voice quality， you asked your provider to implement QoS on the CE routers of your MPLS network. On your LAN， you have also deployed QoS. Users， however， keep complaining about bad voice quality， and the provider does not see matches on the DSCP values that you have asked him to match upon. What is most likely the problem？（）