Batch Simulation: different run numbers but same results

[Alex Berger]

Dear all

I want to do some batch simulations on a computing grid. If I have 50 runs, every run is performed on a different computer.
This works already as expected and I get my 50 results. My problem now is that all results from all 50 runs are exactly the same. I have 4 random number generators in my configuration, so this would suggest that I use the same seed in all simulation runs.

I use cMersenneTwister and I thought that I don't need to specify the seeds because the seed-set is based on the run_number.
Although I have different run_numbers for each run, the seed seems to be exactly the same.

This is how my ini-file looks like:
rng-class=cMersenneTwister
num-rngs = 5
**.mobility.rng-0 = 1
**.wlan[*].mac.rng-0 = 2
**.middle.rng-0 = 3
**.App[*].rng-0 = 4
repeat=50

I start the simulation with:

opp_runall run_script -u Cmdenv -f omnetpp.ini -r <#>

The strange thing is that if I run it on a single computer, then everything is fine and the runs are different.
Does anybody know what may be the reason? Did I forget something? Is it required to set the seeds manually? Any help would be greatly appreciated.