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？（）

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 IOS security feature is configured by the ip inspect inspection-name {in  out} command？（）

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

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

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

Phase I and Phase II DMVPN differ in terms of which of these characteristics？（）

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

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？（）

Which three protocols should be explicitly managed by using Control Plane Policing on an Internet border router？（）