Hi , I came across a SUN server whereby it was installed with additional ethernet card. By right in any configuration, you would probably see the onboard ports Net0,Net1 and so on should correspond to e1000g0,e1000g1...
But instead the ext PCI takes precedence in the order and the Net0 becomes e1000g4 , Net 1 e1000g5 and so on.. Had a hard time troubleshooting untill snoop was run and confirmed that the NIC card was not faulty but instead the "port ordering" has changed. What could be the cause? Any help is much appreciated 
this is no problem. the pci bus is scanned before the internel nics are scanned. so they will become net0 and so on. if you like to have the internal nics to be net0... you have to pull out the additional cards, install the system and then insert the cards again.
Not sure why the system assigned them in that order, but to solve it read man path_to_inst 
So, you can change /etc/path_to_inst, then do: touch /reconfigure; init 6.
Thank you vimes for the info. 
DukeNuke, our practise is to integrate the h/w first then we install the OS. Other systems did not have such issue, only this. But seeing your explanation, it does make sense to follow such procedure.. But for this server, we lack time to do re-installation now..
Thx alot guys! 