客户环境: AF-520---华为S5700---二层交换机 最近发现客户端无法获取AF-520设备上配置的DHCP! 经过华为工程师排查,客户业务正常的版本是V2R3,出问题的版本是V2R7。交换机S5700升级了版本,原来华为交换机从V2R5版本开始检查option44等选项长度为0非法,则丢弃报文。 AF-520设备封装的option44是不符合协议的,长度为0,交换机视为不符合协议规范,按照RFC2132,option44长度至少是4,长度是4的整数倍。请确认该情况是否准确!!! RFC2132 8.5. NetBIOS over TCP/IP Name Server Option TheNetBIOS name server (NBNS) option specifies a list of RFC 1001/1002 [19] [20] NBNS name servers listed in order of preference. The codefor this option is 44. The minimum length of the option is 4octets, and the length must always be a multiple of 4. Code Len Address1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- | 44 | n | a1 | a2 | a3 | a4 | b1| b2 | b3 | b4 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- |