Help debugging standard Gateway configuration problem

Question

I've got a Mac Pro running Lion Server.
It connects to a fixed IP / direct connection to the Internet on Ethernet 1.
The machine, and the services it supports all have good access to the Internet.
It is configured to support a LAN from Ethernet 2.  Wifi connection is disabled.
I used the Gateway Assistant to set up, and:
Ethernet 2 is configured at 192.168.2.1, with DNS set manually to OpenDNS values.  These are the same values as used on Ethernet 1's fixed IP connection (which works fine).
NAT is set to IP Forwarding and Network Address Translation, External Interface is Ethernet 1, and Port Mapping Protocol is enabled.
DHCP is set to distribute values to en1 (which is Ethernet 2) in range 192.168.2.2 to 192.168.2.127.  DNS is set to 192.168.2.1.
The problem I have is, is that although client connections to Ethernet 2 set up pefectly, the connected machines have no connection to the internet: unable to see fqdns or ping IPs directly.
I must be doing something wrong... but can't see it.  Hopefully someone else can...
Thanks in advance for whatever help anyone can provide.

Answer 1

Here are the outputs: hope they are informative
Server - ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
          options=3<RXCSUM,TXCSUM>
          inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
          inet 127.0.0.1 netmask 0xff000000
          inet6 ::1 prefixlen 128
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
          options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
          ether 00:17:f2:00:8e:06
          inet6 fe80::217:f2ff:fe00:8e06%en0 prefixlen 64 scopeid 0x4
          inet 46.33.146.45 netmask 0xfffffff8 broadcast 46.33.146.47
          inet 46.33.146.46 netmask 0xfffffff8 broadcast 46.33.146.47
          media: autoselect (1000baseT <full-duplex,flow-control>)
          status: active
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
          options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
          ether 00:17:f2:00:8e:07
          inet6 fe80::217:f2ff:fe00:8e07%en1 prefixlen 64 scopeid 0x5
          inet 192.168.2.1 netmask 0xffffff00 broadcast 192.168.2.255
          media: autoselect (100baseTX <full-duplex,flow-control>)
          status: active
en2: flags=8823<UP,BROADCAST,SMART,SIMPLEX,MULTICAST> mtu 1500
          ether 00:19:e3:0a:41:ae
          media: autoselect (<unknown type>)
          status: inactive
fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 2030
          lladdr 00:16:cb:ff:fe:6c:6f:f6
          media: autoselect <full-duplex>
          status: inactive
vnic0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
          options=3<RXCSUM,TXCSUM>
          ether 00:1c:42:00:00:08
          inet 10.211.55.2 netmask 0xffffff00 broadcast 10.211.55.255
          media: autoselect
          status: active
vnic1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
          options=3<RXCSUM,TXCSUM>
          ether 00:1c:42:00:00:09
          inet 10.37.129.2 netmask 0xffffff00 broadcast 10.37.129.255
          media: autoselect
          status: active
Server - nslookup
Server:
208.67.220.220
Address:
208.67.220.220#53
Non-authoritative answer:
45.146.33.46.in-addr.arpa
name = www.2gc.org.
Laptop / LAN - ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
          options=3<RXCSUM,TXCSUM>
          inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
          inet 127.0.0.1 netmask 0xff000000
          inet6 ::1 prefixlen 128
          inet6 fd77:51b9:835:a2f3:62c5:47ff:fe08:7d12 prefixlen 128
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8823<UP,BROADCAST,SMART,SIMPLEX,MULTICAST> mtu 1500
          ether 60:c5:47:08:7d:12
          media: autoselect (<unknown type>)
          status: inactive
p2p0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 2304
          ether 02:c5:47:08:7d:12
          media: autoselect
          status: inactive
en2: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
          options=4<VLAN_MTU>
          ether 58:55:ca:22:9a:af
          inet6 fe80::5a55:caff:fe22:9aaf%en2 prefixlen 64 scopeid 0x7
          inet 192.168.2.2 netmask 0xffffff00 broadcast 192.168.2.255
          media: autoselect (100baseTX <full-duplex,flow-control>)
          status: active
Laptop - nslookup
Server:
192.168.2.1
Address:
192.168.2.1#53
45.146.33.46.in-addr.arpa
name = www.2gc.org.