You can boot from the network, but not from a UFSdump image.
You could restore the image onto an NFS server but then you would also have to do some extra work to get the boot to happen (probably gather an inetboot file for tftp and construct some bootparams in /etc/bootparams). Might be easier to just build a jumpstart image first, then modify the parameters to reflect the new image.
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Darren
ufsdump is just a method of moving files (you could do the same with tar or rsync or anything else).
You'd need an NFS server to share the files over the network.
Setting up a network boot server isn't the most trivial thing. I would start by setting up a jumpstart server which would configure /tftpboot and some bootparams for a client.
Once that's working you should just have to export your boot image via NFS, then convert the /etc/bootparams so that the 'root=' line points to your image instead of the jumpstart image.
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Darren