LAN connection dropping, Help. [SOLVED]

[robm999]

Home network with 6-8+ devices connected
Current setup:

Cable modem   <–  pfSense 2.0.1 -->  Linksys Switch --> Local network
                          on VirtualBox         EZXS88R

pfSense is working great running on a virtual machine but I'm trying to move it to a dedicated box.
Dell Optiplex GX270 2.6 GHz, 1GB RAM
on-board Intel Gigabit ethernet
Add PCI 10/100 NIC

pfSense install, boot, and config is fine initially.
Once it starts, most of the time, the computers on the network will have a connection to it for a very short time, if at all.  I will get about 4 pings from pfSense to the other machines and then they're gone. A couple times one machine would stay connected but the others weren't.  The machines on the  LAN can ping each other still. WAN connection on pfSense works fine still.

I have tried 5 different NICs it it. They are a variety of Netgear, Linksys, and DLink cards (drivers: dc, rl, sis).
I don't think it is the cards though because I have swapped LAN/WAN connections so the Intel was LAN and the PCI NIC was WAN and the WAN connection worked fine but the LAN connection dropped.

I have run other firewall systems on different boxes and they all worked fine.
This may not strictly a pfSense issue as another system installed on the same box seems to do the same thing.

I've run out of ideas and could use some help/suggestions.

Thanks
Rob

[robm999]

Well, it seems I may have fixed it.

From what I can tell it was probably the network adapter from the virtual machine may have still been enabled. I thought they had all been disabled when I shut down the VM but perhaps not.

Basically I restarted the firewall with nothing connected on the LAN and then reconnected one device at a time. Before I connected the machine that had the old firewall on VM on it I made sure it was shut down and the adapters configured properly.

Seems to be up and running properly now :)

TL;DR Probably the network seeing 2 gateways on the network and got confused.