实在是翻译不了，请大家帮忙，谢谢！关于CISCO资料

yonggang_zhu

1.关于L2TP的  allows Layer 2 control protocols, such as PDU, LLDP, STP and etc) to be tunneled through a network. \r\n\r\n\r\n2.关于DHCP  snooping:Cisco\'s DHCP Snooping uses DHCP Snooping binding database to maintain MAC, IP address & information about only untrusted interface but not about trusted interfaces. \r\n\r\n3.关于IGMP Filtering：provides control of groups each user can access on a per-port, or a per-port per-VLAN basis\r\n\r\n\r\n4.ony catalyst 3000 and above series with IP Service image support ARP Inspection & IP Source Guard\r\n\r\n\r\n在看资料的时候  这几句话有让人迷糊的地方  谢谢了  ！

bzzh

ony catalyst 3000 and above series with IP Service image support ARP Inspection & IP Source Guard\r\n只有catalyst 3000和以上系列的并且有IP SER IMAGE才能支持ARP INS和IP SO GU两中功能。\r\n\r\nallows Layer 2 control protocols, such as PDU, LLDP, STP and etc) to be tunneled through a network\r\n通道允许承载中有如下二层协议：PDU, LLDP, STP 等等