can not call client behind secondary router of wlan

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a) Before posting your issue you MUST answer to the questions otherwise it
will be rejected (invalid status) by us
b) Please check the issue tacker to avoid duplication
c) Please provide network capture (wireshark) or Android log (DDMS output)
if you want quick response

What steps will reproduce the problem?
1. client A is behind a secondary router, while B is connected to the first
level router;

What is the expected output? What do you see instead?
A can connect to B, while B fail to connect to A

What version of the product are you using? On what operating system?
product version:
android:versionCode="581"
android:versionName="2.581.1247"
nexus five

Please provide any additional information below.
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Original issue reported on code.google.com by `liuzh...@gmail.com` on 27 Mar 2015 at 8:02