NetInstall images not appearing.

NetBoot will not cross subnet boundaries without configuring NetBoot helpers (relays). The simple answer is to put the NetBoot server on the client subnet.

'man bootpd'

The short version is that you need to set up a machine on the client subnet that relays bootp requests to the server.

The setup would look something like:

1. Edit /etc/bootpd.plist:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>relay_enabled</key>

<array>

<string>en0</string>

</array>

<key>relay_ip_list</key>

<array>

<string>172.16.200.xxx</string>

</array>

</dict>

</plist>

2. Bring up bootpd:

$ sudo launchctl load -w /System/Library/LaunchDaemons/bootps.plist

I'm not sure I fully understand why the network admin wants to mitigate data flow? Surely some data (probably lots of it) needs to flow to and from your server otherwise what would be the point? An IP_underscore helper address on at least one of your core switches will act exactly the same as a workstation configured as a relay. Makes far better use of your switching hardware as that's what they're meant to do.

Just speculating but if this is a predominantly windows environment (I'm guessing AD?) then at the very least WDS and more than likely SCCM is the deployment method used by the network admin. If that's the case adding an IP helper address can't hurt.

My 2p

I totally agree, and it doesn't suffer from the potential "oops, somebody shut down the relay client" issue. 😉