两块开发板，一块正常一块网络有问题，但两块板子都可以配置网络，，好的板子地址设置为192.168.1.230，问题板子设置为192.168.1.231，用交叉网线将两块板子连接在一起，通过超级终端看好的板子，出现下面的情况（两块板子ping不通）。想请教下，坏的板子问题可能在哪儿，请给了思路，谢谢。
[root@FriendlyARM /]#
[root@FriendlyARM /]#
[root@FriendlyARM /]# eth0: link down
eth0: link up, 100Mbps, full-duplex, lpa 0x41E1
eth0: link down
eth0: link up, 100Mbps, full-duplex, lpa 0x41E1
eth0: link down
eth0: link up, 100Mbps, full-duplex, lpa 0x41E1
eth0: link down

可能他们的mac地址相同导致的。

感谢版主的回复，，我单独把坏的板子和路由器连起来的时候，也没办法ping通路由器的，，，

又实验了用 交叉线将板子和电脑连接起来，ip设在同一个网段，，电脑端也一直重复显示 网线没插好（一会好，一会不好）


另外板子直接连路由(非交叉线)，ping路由的时候，给的提示
--- 192.168.1.1 ping statistics ---
876 packets transmitted, 0 packets received, 100% packet loss

考虑到可能是dm9000的问题，又换了个批次的芯片，暂时不会出现那种时而连接上时而断开的问题了，但有了新的问题，还是ping不通网关。出现的问题如下。
[root@FriendlyARM /]# ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes                 //等待了一会后出现下面的情况
------------[ cut here ]------------
WARNING: at net/sched/sch_generic.c:226 dev_watchdog+0x260/0x280()
NETDEV WATCHDOG: eth0 (dm9000): transmit timed out
Modules linked in:
[<c02d37e8>] (dump_stack+0x0/0x14) from [<c003adac>] (warn_slowpath+0x70/0xa8)
[<c003ad3c>] (warn_slowpath+0x0/0xa8) from [<c02596e8>] (dev_watchdog+0x260/0x28
0)
r3:c383f800 r2:c03ac8b0
r7:00000000 r6:c383f800 r5:c042c584 r4:c03d4168
[<c0259488>] (dev_watchdog+0x0/0x280) from [<c0044c80>] (run_timer_softirq+0x1b0
/0x230)
r7:c0259488 r6:c03cdea0 r5:00000100 r4:c04209e0
[<c0044ad0>] (run_timer_softirq+0x0/0x230) from [<c0040204>] (__do_softirq+0x7c/
0xfc)
[<c0040188>] (__do_softirq+0x0/0xfc) from [<c00402cc>] (irq_exit+0x48/0x50)
[<c0040284>] (irq_exit+0x0/0x50) from [<c0028048>] (__exception_text_start+0x48/
0x70)
[<c0028000>] (__exception_text_start+0x0/0x70) from [<c0028a44>] (__irq_svc+0x24
/0xa0)
Exception stack(0xc03cdf40 to 0xc03cdf88)
df40: f4100000 00000032 f4100000 60000013 c0029edc c03cc000 c0029edc c03ff2a4
df60: 3001c920 41129200 3001c8ec c03cdf94 c03cdf98 c03cdf88 c002a4f8 c0029f3c
df80: 60000013 ffffffff
r7:c03ff2a4 r6:00004000 r5:f4000000 r4:ffffffff
[<c0029edc>] (default_idle+0x0/0xac) from [<c002a4f8>] (cpu_idle+0x4c/0x68)
[<c002a4ac>] (cpu_idle+0x0/0x68) from [<c02d2124>] (rest_init+0x5c/0x70)
r7:c03d0440 r6:c001e000 r5:c03ff260 r4:c0423284
[<c02d20c8>] (rest_init+0x0/0x70) from [<c0008930>] (start_kernel+0x200/0x268)
[<c0008730>] (start_kernel+0x0/0x268) from [<30008034>] (0x30008034)
r6:c001ed34 r5:c03ff37c r4:c0007175
---[ end trace abf02f7e31a51fb4 ]---
^C
--- 192.168.1.1 ping statistics ---
19 packets transmitted, 0 packets received, 100% packet loss

结题帖---------------------------------------------

那个批次芯片的问题，换了一个批次的就好了，，，