Support Element Network Segregation

[FaultyWarrior]

Question for anyone with experience doing mainframe infrastructure.

I currently have a separate token ring network for my machine's two support elements plus the hardware management console to talk on. I need to connect the support elements to an Ethernet network to allow for IPL via FTP.

If I'm understanding the manuals right, the support elements can have only one path between each other and/or with the HMC (that is, I can't connect all 3 devices via both token ring and Ethernet at the same time).

Does anyone know if simply having the machines on different Ethernet subnets is OK, or do they use some kind of auto-discovery protocol and will still manage to cause issues unless I separate all 3 machines onto separate VLANs?

Machine is a z800 btw, so OS/2 SE's and HMC.


p.s.
No, I can't just ditch the token ring network, since I don't have the EtherJet Management Card for my HMC; and they're not easy to come by.