单项选择题 In a Bridged 1483 network, you suspect ATM interface 6/2.1 is receiving cells but may not be transmitting them. The interface has an ATM PVC configuration of atm pvc 33 0 33 aal5snap . How do you baseline this interface and display recent ATM cell statistics?（）

单项选择题 In a Bridged 1483 network, an ISP has received complaints from their subscribers of denial of service attacks. The ISP suspects these attacks are coming from other subscribers that share the same IP unnumbered interface on the ERX. What can be done to solve this problem?（）

单项选择题 You can successfully ping a Bridged 1483 customers workstation from the local ERX. However, a remote ERX router in your network cannot ping that same device. What could be causing this problem?（）