Spotty Internet service...Steps to test SBS w/ Single NIC 1

[wahnula]

Hello all,

I currently have a small-office network, 10 clients, running SBS 2003 SP2, 2 NICs, SBS doing DHCP, with a SonicWALL firewall on the WAN and a gigabit switch on the LAN, with WAPS & printers etc. I set this entire network up personally about five years ago, and it has been smooth sailing for the most part.

Lately the Internet has been spotty, slow to load or failing, and as a troubleshooting step I would like to return the SBS to single-NIC to see if the problem is within SBS' handling of Internet traffic.

I have already tested everything else, a workstation plugged directly into the cable modem is lightning fast, so I know it's not the ISP.

Unfortunately, I'm in high season in my "other" job, and time is of the essence (isn't it always?). If someone could offer a quick checklist of the procedures to toggle between single & double NIC it would be greatly appreciated. I can use the SonicWALL to do DHCP (temporarily or permanently, but I really like SBS' handling of DHCP). I have visualized this scenario:

1. Disconnect cable from WAN NIC; plug the switch's WAN out to SonicWall LAN in;
2. Run the CEICW and set up SBS as a single-NIC machine, using the Server Local Area NIC.

It could not be this easy, could it? Thanks as always.

Tony

Users helping Users...

 

[ShackDaddy]

To be honest, I've always started from a single-NIC position, so I'm not completely sure what your process should be, but what you describe above is exactly where I'd start. ;-)

But you ARE forgetting something: the internal interface of the SonicWall is probably on a different subnet than your clients are, so you're going to want to reIP the internal interface of your SonicWall for this to work.

Then I'd reconfigure DHCP to hand out the Sonicwall IP to the clients as their default router (they are pointing at the server right now, correct?), and then do an IPCONFIG /RENEW on each client to make sure they pick up the new router settings.

Dave Shackelford
ThirdTier.net

 

[wahnula]

Right now all the clients are pointing to the SBS server for DNS (192.168.16.2). This part is easy enough as I can set them to all get IP addresses automatically. Would SBS still be the DHCP host or should that task now go to the Sonicwall?

You are correct, the subnet of the Sonicwall is 192.168.0.xx and the IP of the server is set to 192.168.1.101. This would stay the same, correct? I am not sure if you mean the Sonicwall should be the DHCP host or not.

Tony

Users helping Users...

 

[ShackDaddy]

Hold up. This is getting two confusing. So far you've mentioned three different subnets. Could you itemize your subnets so that we can be clear? I assumed you had two.

Unless we need to do something special for your network, once you move to a single-NIC solution, you'd only have a SINGLE private subnet, and the server, the clients, and the internal NIC of the SonicWall would all be on that subnet.

You'd still use your SBS for DHCP, but instead of having the clients go to your SBS as their default gateway, they'd need to go straight to the SonicWall's LAN interface, which would now have an IP on the subnet that it shares with the clients.

Dave Shackelford
ThirdTier.net

 

[wahnula]

Got it. There are only two subnets, 192.168.16.xx on the internal NIC, and 192.168.0.xx on the external NIC. I was planning on using the external NIC as the single NIC, so once I assign that subnet to the clients and re-run the CEICW that should be OK. 192.168.0.101 is the IP address of the external NIC, which will remain the same.

Right now my topology is, from the ISP's modem:

Cable modem->Sonicwall->external NIC (192.168.0.101)->SBS doing DHCP->internal NIC(192.168.16.2)->gigabit switch->clients, printers & WAPs.

My new topology would be:

Cable modem->Sonicwall->gigabit switch->SBS, clients, etc.

This would be a good testing platform and I just might leave it. My plan to get there:

1. Change all clients to get IP address and DNS server automatically;
2. Disconnect external NIC cable from Sonicwall and connect to gigabit switch
3. Connect gigabit switch to Sonicwall
4. Re-run the CEICW to change SBS from dul to single NIC and supply the correct subnet
5. Release/renew clients' IP addresses
6. Test

Sound OK?

Tony

Users helping Users...

 

[ShackDaddy]

Zounds gut.

Dave Shackelford
ThirdTier.net

 

[wahnula]

It turned out to be a DNS issue...our ISP changed DNS servers, we did not receive any notice of the change, but a local tech knew all about it. Thanks anyway Dave!

Tony

Users helping Users...