SG200-18 Fails to pass DHCP requests?

[mitch.lockhart]

I have a sg200-18 connected via one of the ports to my ISP's router/modem.  Using an unmanaged switch everything works as expected, but after a few days on my sg200 my two computers fail to get assigned IP's and cannot connect to anything.  I also have a couple printers that seem to have no problems getting their IP's passed through to the router as I can use them fine from my machines when connected to the unmanaged switch.

Is there a possibility I don't have my switch setup properly to know that all outgoing data must go to the router, or UDP traffic is being dropped somehow?

[Tom Watts]

Hi Mitch, do you have any configuration on the switch at all?

If it is a brand new install very first thing to do would be load the newest firmware and factory reset the switch then test at default parameter. Give this a try and post back.

-Tom
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[mitch.lockhart]

I initially had some minor configuration but it has since been removed. I updated the firmware after my machine would not get an ip the first time. So at this moment is it updated with latest firmware and no real configuration to speak of.

The switch is connected to my router on port 17 and my computer plugs into into port 1 or 2.

I tried setting port 17 in the config to be a "router" port. No change though.

[Tom Watts]

Mitch, please factory reset the switch and do not configure it. Once done, see if it works similar to your unmanaged switch. If it still does not work, log in to the switch and manually set port speed to 100 full duplex. If still does not work, try to set a static IP address on the computer which you know will work and see if you can communicate. If communication with a static IP fails, change to use different ports and/or wires.

-Tom
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[mitch.lockhart]

Hi Tom,

I have tried this before and unfortunately the results are the same now.  I reset the switch.  The switch managed to get an IP from my router allowing me to figure out where to connect to.  My PC could not connect via the switch.  I tried setting the speed to 100M full duplex, and while the switch showed the port as connected at that speed, I could pass no data through the switch to the router.  I tried setting my PC's IP to be static (this might be the confusing part, I set the DNS to be the router address and not the switch address).  Still it did not work.

I have tried various ports and wires, and they all work fine on the unmanaged switch or directly to the router.  Right now I am running on my macbook connected wirelessly and I tried connecting my printer's network cable to the ethernet on this computer and again the switch registered it as connected but no IP assigned.

One thing to note that I have tried in the past is connect a simply old linksys router instead of my main ISP router.  I thought there was likely something wrong with my router so I tried the linksys.  The same results; my computers would not get IP's assigned by the router.

Might I have a defective switch?  Is there some diagnostics I can do?

Finally, when I first installed the switch it did work for a couple days.  And I have had it working since but it is very sporadic.  Mostly I have to reset everything and restart my computers and they seem to get an IP.  After a couple days (I assume the DHCP request expired) it cannot get an IP on resume or boot up.  A reboot this time did not seem to solve it.

[mitch.lockhart]

I want to quickly add that I just switched ports to the unmanaged switch, and my static IP setting worked immediately.  I can even connect to the switch via the router.

Computer -> unmanaged switch -> router -> SG200-18

When I did have it working in the beginning the transfer speeds I was getting were low.  I tried running some speed tests on it and found the UDP showed a lot of errors.  Not sure I can qualify this now as I can't get it all working again, but perhaps my DHCP requests are encountering errors?  Anything I can do to diagnose issues?

Mitch

[Tom Watts]

Hi Mitch, I don't think it's worth the time to try to figure it out. Sounds like faulty hardware. I'd exchange the switch at the vendor or call the small business support requesting RMA.

-Tom
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[mitch.lockhart]

Thanks Tom,

I will talk to the vendor and see what they can do.  Unfortunately I tossed the packaging, but for a company like Cisco that doesn't seem like it should be an issue.