linking...
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Gateway_IP multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol IP_Addr multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Phy_Addr multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Rx_Buffer multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Sub_Mask multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Tx_Buffer multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Temp_Buffer multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol UART_Rx_Buffer multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol UART_Tx_Buffer multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol RxCounter multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S0_Data multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S0_State multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S1_Data multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S1_State multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S2_Data multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S2_State multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S3_Data multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol S3_State multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Sn_DPort multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Sn_Mode multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Sn_Port multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol TxCounter multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol TxIndex multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol UART_DataReceive multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol W5100_Interrupt multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol Sn_DIP multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol close multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol connect multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol disconnect multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol getSockStatus multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol listen multiply defined (by device.o and demo.o).
.\Obj\STM3210E-EVAL.axf: Error: L6200E: Symbol open multiply defined (by device.o and demo.o).
Target not created

我都快折腾两天了，这不争气的程序还是很不给面子

应该是两个文件对同一个 Symbol 进行了重复定义吧

这个我也不太清楚，网上有说是因为那些变量定义时没有加extern，后来我挨边找了找，把没加的都加上现在就有一条这种提示了：.\Obj\STM3210E-EVAL.axf: Error: L6218E: Undefined symbol Sn_DIP (referred from demo.o).   可是Sn_DIP在定义时已经加extern了啊。这一个错误怎么都搞不定了……而且错误还不能自动定位的那一行。
哪位高人能指点一二啊

我遇到过了  那些文件全是.o的文件
搞了好久也没搞出来
不过后来找了一个比较好的模板，把主程序移植一下。进而再次编译的时候就通过了，如果需要模板的话加qq939842278，我也刚学习这个！

很简单，你在不同的文件多次定义了同样的变量，解决办法是加extern没错，但你得注意，总得留一个定义不要加extern，不然就会报这个变量没有定义啊，提示说的很清楚了。你全部都加了extern当然又会报错

很简单，你在不同的文件多次定义了同样的变量，解决办法是加extern没错，但你得注意，总得留一个定义不要加extern，不然就会报这个变量没有定义啊，提示说的很清楚了。你全部都加了extern当然又会报错

重复定义，工程中找一下这几个定义。

是的，我也遇到过这样的错误。就定义重复了或者 没有加extern ,
  注意 定义类型的 头文件 要放在最前面，不然的话 也会错误的。

太长了吧，应该是没有找到库

可能是没有加.C

确实是重复定义。

重复定义，删除重复包含的文件就好了