Packet Sniffers like ethereal , dsniff , driftnet , urlsnarf , and msgsnarf can help sniff-out useless traffic like IM messages that waste bandwidth .
报文嗅探器,例如ethereal、dsniff、driftnet、urlsnarf和msgsnarf,可以帮助过滤未用的通信,例如会浪费带宽的IM消息。