dhcp relay doesn't work?please help

[constant]

Hi all:
           I'm sorry my English is not good,please be patient.thank you!! I'm doing a 

project based on openwrt (SOC: Atheros ar9341) .As the following chart shows, I

 need a router as a dhcp relay agent,so i use isc-dhcp-relay

 

dhcp server <------------> eth0 (router) eth1 <------------>dhcp client

 

dhcp server ip:192.168.2.1	       a normal dhcp server 
router eth0 ip:192.168.2.101         eth0 get the ip from dhcp server
router eth1 ip:192.168.1.1             static ip,eth1 is directed connected to lan,the bridged interface name is br-lan

I enter the command:

	dhcrelay -i br-lan 192.168.2.1

However, even though I tried two available dhcp server, the client can not obtain an IP address.

for dhcp server 1,wireshark shows 

	1) router forwards dhcp discover from client to server         (unicast)

	2) server replies dhcp offer to router		             (broadcast)

	3) router doesn't send anything to client

for dhcp server 2,wireshark shows

	1) router forwards dhcp discover from client to server         (unicast)

	2)server replies nothing.

Does anyone have any suggestions? Thank you very much!
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