There are a hugh amount of documents here that will guide you in preparing your environment and the DS-components to be able to work in a segemented setup.

Search for "segements", "vlan", "pxe" seperate or combined...  That will do that part.  Do not be scared when you see documents based on DS5.5 or DS6.8...  These do explain a lot on the basics/design.

That said, this feels like a multicast thing.  Network components rare by default not keen on Multicasting.  Especially when Routers are in between, or an rounter-functionality.

What I do in these kind of environments is having a vlan-nic in the DS (and if exist also for other seperated DS-Components) for every vlan and make sure that all DS-related communication is done directly to/with that vlan.  All communication is still going through the router, but within the vlan environment.  That wil not slow down your routing (at least a LOT less).  Meaning WOL, PXE, 401,402, and other ports/functions need to be configured correctly. 

These few words are not your solution, but I hope it can bring you on the right track.

Good Luck!

Have you configured the lmhost files in both the Linux and WinPe boot images? if I rememer correctly the lmhost file is not configured by default. Sometimes it helps to configure the lmhost file so that the client knows what the IP address of the DS is.

just my 2 cents.

You'll want to verify that you can access not only the DS server, but also ensure that any other servers that might house the images, etc.

If you are utilizing PXE, you may need an iphelper to point to your altiris pxe server.

Check with your networking group that runs your switches to see if there is anything special setup on the staging subnet in relation to the other subnet/vlans.

I would even issue a "Wait" command via a job and see what the winpe ip config looks like.  It might be something simple like having a static IP set, instead of using DHCP, or a gateway issue.

There are very simple tests you can do to see what is wrong, but first, a bit of explanation.

1) because you're in WinPE, the IPHelpers and/or Forced Mode is NOT an issue.  Those only help you get to the PXE server, which happens LONG before you have to worry about WinPE.

2) Network access for the NIC when getting to the PXE server is completely seperate from network access in WinPE.  So, just because you can get to the server for PXE, doesn't imply you can for WinPE.  Unfortunately, because you've not mentioned that you PXE booted, we also don't know if you have DHCP or Network access at this point.  You can also boot to WinPE from a local partition.

3) WinPE is the last part of the "pxe boot process" so if you're in WinPE, that's really good - it means all of PXE and TFTP are just fine.  This is excellent.

4) IF you were using PXE to get to WinPE, then DHCP is working.  IF you loaded WinPE via some other method (local drive, thumb drive, CD, whatever), then we don't even know if DHCP is working or not.

What therefore is left?  Well, there are some things we need to do.

1) Did you get a message like "retrying DHCP"?  If you got that message, then almost certainly you are lacking the correct drivers for your NIC.

2) Are you SURE you have DHCP in this location?  If you WERE using PXE to get to WinPE, then you almost certainly do.  But it's possible you don't.  Be sure about that.  Check in Production to see if you're using Fixed IP or not.  That's not too bad to configure via the Bootdisk Creator

3) The suggestion for the LMHost modifications are good if you're having name resolution problems.  DNS issues are more common than you might think!

Good luck M8