7506E交换机DHCP RELAY，获取不到地址

互联地址互通正常，VLAN 88 下获取不到地址

服务端与中继通过IP互联地址互访

服务端（已有DHCP服务，可正常分配）

 ip pool 100

gateway-list 192.168.88.254

 network  192.168.88.2   mask 255.255.255.0 

 dns-list 114.114.114.114

中继

dhcp relay server-group 0 ip 172.16.0.2

 Vlan-interface88

 ip address 192.168.88.254 255.255.255.0 

 dhcp select relay 

 dhcp relay server-select 0 

[7506E]dis dhcp relay statistics 

 Bad packets received: 0 

 DHCP packets received from clients: 192

 DHCPDISCOVER packets received: 192 

 DHCPREQUEST packets received: 0 

 DHCPINFORM packets received: 0 

 DHCPRELEASE packets received: 0 

 DHCPDECLINE packets received: 0 

 BOOTPREQUEST packets received: 0 

 DHCP packets received from servers: 0 

 DHCPOFFER packets received: 0 

 DHCPACK packets received: 0 

 DHCPNAK packets received: 0 

 BOOTPREPLY packets received: 0 

 DHCP packets relayed to servers: 192 

 DHCPDISCOVER packets relayed: 192 

 DHCPREQUEST packets relayed: 0 

 DHCPINFORM packets relayed: 0 

 DHCPRELEASE packets relayed: 0 

 DHCPDECLINE packets relayed: 0 

 BOOTPREQUEST packets relayed: 0 

 DHCP packets relayed to clients: 0 

 DHCPOFFER packets relayed: 0 

 DHCPACK packets relayed: 0 

 DHCPNAK packets relayed: 0 

 BOOTPREPLY packets relayed: 0 

 DHCP packets sent to servers: 0

 DHCPDISCOVER packets sent: 0 

 DHCPREQUEST packets sent: 0 

 DHCPINFORM packets sent: 0 

 DHCPRELEASE packets sent: 0 

 DHCPDECLINE packets sent: 0 

 BOOTPREQUEST packets sent: 0 

 DHCP packets sent to clients: 0 

 DHCPOFFER packets sent: 0 

 DHCPACK packets sent: 0 

 DHCPNAK packets sent: 0 

 BOOTPREPLY packets sent: 0