try this...

Assume the manual is:
http://www.tenda.cn/uploadfile/downloads/uploadfile/201204/A5-EN.zip

Your Cisco router's inside IP address: 192.168.0.1

1. (Page 30) Change it to, say 192.168.0.2 (you may need to do something in your Cisco router, but let's try not to first)
(Do not forget what's the IPs you've changed from and to!!!)

You probably need to re-login again to 192.168.0.2 (your Tenda's new IP address)

2. (Page 43) Disable DHCP

所有跟帖： 

• 下载了该说明书，把Lansetting 中Tenda router 从192.168.2.1改成 192.168.0.2,并在D -lmjlmj- ♂ (259 bytes) () 04/27/2012 postreply 12:35:55

• 我支了个臭招。。。 -slow_quick- ♂ (513 bytes) () 04/27/2012 postreply 13:03:27

• 还是谢谢你。等家人不用网时我试试Cisco。 -lmjlmj- ♂ (0 bytes) () 04/27/2012 postreply 13:22:34

• Model DPC 3825 DOCSIS 3.0 Gateway -lmjlmj- ♂ (0 bytes) () 04/27/2012 postreply 13:23:58

• Switch这招好像走不通 -slow_quick- ♂ (52 bytes) () 04/27/2012 postreply 14:02:48

• 回复：下载了该说明书，把Lansetting 中Tenda router 从192.168.2.1改成 192.168.0.2, -slow_quick- ♂ (273 bytes) () 04/27/2012 postreply 13:18:33

• 看来，为了用外网地址，实在不行就放弃tenda，换camera天线，从现在2dbi 换成 7dbi -lmjlmj- ♂ (0 bytes) () 04/27/2012 postreply 12:46:50

• 这也许更简单，先试易拉罐什么的:} -slow_quick- ♂ (0 bytes) () 04/27/2012 postreply 13:05:37