Internet Sharing 10.8 Server Doesn't Start

Question

I have upgraded to 10.8 ML + Server from 10.7.
Wireless internet (4G) is managed using AirCard Watcher on directIP interface (en6).
Internet Sharing is ON
     Share your connection from direct IP
      To computers using Ethernet
I am expecting the server to act as a DHCP server.  Articles elsewhere suggest this will happen (eg http://support.apple.com/kb/HT5412)
But in /etc/bootpd.plist this looks wrong:
mini:etc charlie$ more 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/>
</plist>
Where is the rest of it?
This is basically doing nothing?
Toggling "Internet Sharing" in the sharing pane makes /etc/bootpd.plist disappear.
What is going on?!

Answer 1

DHCP is now in 10.8.2/Server 2.1.0 as an explicit setting.
When you select 'Internet Sharing' (System Preferences-Sharing) it automatically configures 192.168.2/24 DHCP network.
But NAT still doesn't seem to be working. 
Clients are appearing in the client list.  IP addresses seem to be assigned ok looking directly on each device.
But when you try to access a URL from any of the connected devices it just times out.
How can you jig about with NAT at command line?
OR
How can you tell if NAT is working otherwise?
Here is the bootpd.plist file contents (which now seem to be created successfully).
<?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>Subnets</key>
        <array>
                <dict>
                        <key>_creator</key>
                        <string>com.apple.InternetSharing</string>
                        <key>allocate</key>
                        <true/>
                        <key>dhcp_domain_name_server</key>
                        <array>
                                <string>192.168.2.1</string>
                        </array>
                        <key>dhcp_router</key>
                        <string>192.168.2.1</string>
                        <key>lease_max</key>
                        <integer>86400</integer>
                        <key>lease_min</key>
                        <integer>86400</integer>
                        <key>name</key>
                        <string>192.168.2/24</string>
                        <key>net_address</key>
                        <string>192.168.2.0</string>
                        <key>net_mask</key>
                        <string>255.255.255.0</string>
                        <key>net_range</key>
                        <array>
                                <string>192.168.2.2</string>
                                <string>192.168.2.254</string>
                        </array>
                </dict>
        </array>
        <key>bootp_enabled</key>
        <false/>
        <key>detect_other_dhcp_server</key>
        <true/>
        <key>dhcp_enabled</key>
        <array>
                <string>bridge0</string>
        </array>
        <key>use_server_config_for_dhcp_options</key>
        <false/>
</dict>
</plist>