单项选择题 Refer to the exhibit. What type of issue does this error log indicate if the IP address in the error log is located off of the Router A WAN?（）

问答题 给了两段documentation里的描述，问这个时候发哪种类型的ICMP包。 The interface on which the packet comes into the router is the same interface on which the packet gets routed out. The subnet or network of the source IP address is on the same subnet or network of the next-hop IP address of the routed packet.

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， an unauthorized switch 2 was found. This unauthorized switch has been a regular problem， assuming the root bridge function under the spanning-tree domain and causing the Engineering VLAN to be unstable. Which three of these actions could be suggested to fix the problem？（）