Choose two commands that are required to enable multicast on a router， when it is known that the receivers use a specific functionality of IGMPv3.（）

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？（）

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 is the command to configure RSVP to reserve up to one-tenth of a Gigabit link， but only allow each individual flow to use 1 MB/s？（）

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？（）

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？（）

Which statement is correct about an OSPF sham-link？（）

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

Which router is doing LSA type 7 to type 5 translation，and why？（）