Why windows from 2nd server can not be shown when an intermediate ssh server is used?

[Peng Yu]

Hi,

Suppose I have three linux servers A, B and C.

On A, I run `ssh -Y B` to login to B (programs using windows on B can
be shown on A). Then, I login to C from B using the command `ssh -Y
C`. But, programs in can not show windows on A.

Does anybody know how to let A show windows from C? Thanks.

-- 
Regards,
Peng