Win98, Win2kserver , xclients inside NAT [1]

I have the following conditions: (SunSolaris)xclients are inside NAT, xmanager1.3.9 is established on machines(Win98, Win2kserver(no PDC)) outside of NAT, taking place in one local network.
Mapping on router(NAT) for special ports:
UDP 6000
TCP 21
TCP 23
The Xbrowser on WIN2Kserver finds xclients machines inside NAT, bat the Xbrowser on Win98 does not find.
Ping from xclients machines through NAT to Win98- yes.
Why? How to adjust NAT?

Xbrowser sends an XDMCP packet to UDP 177 port of the Sun machine. So, you need to forward UDP 177 of the NAT to that port of the Sun machine.

Hope to solve the problem.

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Technical Support