c6678 SGMII寄存器显示已经linkup，但是为何ping不通

自己在helloworld的例程上稍微改动了一下，运行时提示：

[C66xx_0] 

QMSS successfully initialized
CPPI successfully initialized
PA successfully initialized

TCP/IP Stack 'Hello World!' Application

TCP/IP Stack 'Hello World!' Application

PASS successfully initialized
Ethernet subsystem successfully initialized
Ethernet eventId : 48 and vectId (Interrupt) : 7
Registration of the EMAC Successful, waiting for link up ..
Network Added: If-1:192.168.0.234

我使用的是SGMII0 PHY模式，通过查看SGMII_CONTROL STATUS MR_ADV_ABILITY三个寄存器值为：00000001 0000003D 00001801，我看了一下这几个寄存器的值也应该正确，但是我和PC机 就是ping不通，请问大家有遇见这种情况的吗？怎么解决的？