Ad Hoc small business issue

Ugh, ok. I’ve been roped into an IT issue.

Small Business network. Connected to a home/business cellular modem.

5PCs and various devices on one Netgear router, with a wireless hub on one port. This connects to a wireless booster that connects to the house modem, which has various devices connected to it.

They’ve had some issues getting devices to talk to each other off and on. They’ve tried this and that to fix the issues, but it’s mostly resolved over time.

This particular time the POS PC has stopped talking to the Quickbooks server. I poked around some, played with making static IPs for the server and the workstation. (Server as in the Quickbooks definition, not a real server) I can sometimes see the server machine, but can’t always see the files on it. And can never keep the connection long enough to get quickbooks to link.

After poking around I find that they have a double NAT. The router in the office and the modem in the house are both providing that service.

I’ve been too out of this game. I’m really concerned if I turn the NAT off on the office router that everything will go boom. It should ideally be set up as a simple access point, leaving the modem to assign everything. But I don’t know exactly what happens if I change that and it dies.

All this from an office where three computers can see five machines and one can see two and the fifth can only see three.

4 windows ten machines and 1 windows 7.

Thoughts appreciated for going forward.

Which of the devices is connected to the outside world? The router or the modem? I’m guessing the modem but I want to be sure.

1 Like

I’m guessing double nat is an issue. If there’s a need for keeping the House network different from he Business network, use VLANs if possible.

I’m with @balance. When you started talking about connectivity dropping on and off my immediate thought was IP address conflicts - which could easily happen with a double NAT situation.

I would turn off one of the NAT servers, then renew all the IP addresses

Check this:

and this

Start by drawing up a schematic diagram of the network. Then place the IP+subnet mask+gateway next to each device.

Then show it to us. :slight_smile:

1 Like

Yeah, it’s the modem.

Turns out they changed everything a couple weeks ago and made an occasional problem worse.

The reason for the change is cell phones kept trying to hang on to the connection to the office building when they were in their house. And I think they’ll just have to deal with that.

VLAN is something I totally forgot about. I can run down that rabbit hole.

I can’t actually catch the IP conflict as it happens, but my assumption is that it’s the NAT creating some sort of mess.

In my prior lives I would have blown the whole thing up and started over, some of the machines are over 5-6 years old and only two are the same machine, which is an HP econobox that’s several years old. And of course this whole time I’m actually supposed to be helping pull honey, but they are half paralyzed by this mess.

I’m going to try to turn the end point router into a simple access point and see what happens. I can always back up to the saved config.

Even easier solution. Take wireless router out, out in dumb switch. Set cellular modem as echo for while thing and sit back something propagate.

Still can’t get QuickBooks machines to play nice, but all other computers can see everyone else.

Then plug wireless router into dumb switch as bridge. I

Hopefully today they’ll have magically found each other overnight. I cannot figure out why every other machine can connect and browse through the QB server, but the one I want to can only see it.

  • List item