nbproc + server source = no free ports? (no replies)

Hello,

I'm getting lots of "no free ports" errors with such setup (simplified
version):

frontend front
...
bind-process 1 2
default_backend back

backend back
...
server ... source 192.168.0.10:1025-49999
server ... source 192.168.0.11:1025-49999

I think that's because I use the same ip and port range across multiple
processes. Is there a way to avoid this? May be I can set unique ip and
port range per process somehow?

Thanks a lot,
Dmitry.