多项选择题 Refer to the exhibit. Users from the Engineering VLAN complain that every time Business VLAN users have a network connectivity issue，the Engineering VLAN users usually have problems experiencing slow response or network connectivity problems. After troubleshooting， anunauthorized switch 2 was found.This unauthorized switch has been a regular problem， assuming the root bridge function under thespanning-tree domain and causing the Engineering VLAN to be unstable. Which three of these actionscould be suggested to fix the problem？（）

多项选择题 Refer to the exhibit. As a network administrator， you have configured a dual-rate， dual-bucket policer in accordance with RFC 2698 on the serial interface of you router， connecting to your provider. The SLA with your provider states that you should only send AF31 （limited to 150 kb/s）， AF32 （limited to 50 kb/s）and AF33 （best effort）. Your service provider claims you are not conforming to the SLA.Which two things are wrong with this configuration？ （）

问答题 whatdevicesendsIGMPQuerymessages？