DHCPNACK & Belkin F5D7230-4

The message means that your XP Pro SP2 client has requested a DHCP lease renewal, and the access point has denied it. Usually, DHCP lease renewal requests are initiated by the client at about half the lease time. Run: ipconfig /all | more and see if it discloses the lease time. You can force an early renewal with: ipconfig /renew and watch for errors in the event viewer. DHCP renewals are also initiated by XP after the connection has been lost for some time. (I don't know how long). The idea is to check if the DHCP server hasn't timed out and delivered the IP address to some other client computah.

I've also seen the event log full of DHCPNACK messages when someone is trying to hijack my connection using MAC address spoofing. It can also happen if someone has changed your XP SP2 box's MAC address to duplicate another machine on the network. XP uses the MAC address in the registry, not directly from the card. Run: arp -a and proporties for your ethernet card to see if any MAC addresses are off. This is especially common for machines that have been cloned from a common system image, where the MAC address in the registry is duplicated in the cloned machines.

You might wanna try temporarily setting your XP box to a fixed IP address and see if the disconnect problem is specific to the DHCP part of the puzzle. I'll guess(tm) that you'll still get disconnects.

Thanks. VERY helpful and more than expected.

Both my neighbor and I live in a rural area and have what the ISP is calling "wireless DSL." We both have the Belkin routers. He did have a Netgear and they switched him out. His "disconnect" is more often than mine.

Since we're so far out, I doubt that someone is hacking, but one can never tell.

Thanks for the tips.

Jeff Liebermann wrote:

Thanks, but I'm not sure they're really very useful. More like me thinking "how would I create such a problem" type of thinking.

Holdit! "Wireless DSL" is probably a WISP (wireless ISP). If they're also using 2.4GHz, you have a built in local source of interference. There's you're problem. It doesn't take much junk on the same channel to cause a disconnect. I'm not sure how the DHCP failure is related to the disconnects, but it's worth investigating. Turn OFF the Wireless DSL box and run some local wireless traffic between machines. See if the DHCP errors magically go away.

Post a URL to these guys and I'll see if I can figure out what they're doing. If they're using 802.11b/g, just find an unused channel (1, 6, or 11). If they're using frequency hopping or some proprietary modulation scheme, you'll probably need to switch bands to 802.11a.

Every 15 year old in the neighborhood with a wireless device has tried to hack my system. I think it's now a teenage right of passage or something. Even the girls do it. When I was operating a BBS and later a UUCP gateway in my office, it seemed that the local high skool electronics class was using my system as a test exam in computer breaking and entry. I really learned about security from those kids.

Not sure what you are referring to, but YOUR reply was what I meant.

they're

channel

machines.

The ISP's modem is a propriatary WAVERIDER something or other at 900 mHz, so I'm told. Hey it works and all we have out here is a gravel quarry and LOTS of dairies (along with the warm summer smell).

they're

Well there aren't any kids out here yet. All three are under 5 and the rest are Lamas, horses, cows, and coyotes. Really, they'd have to part in the driveway to get a good signal with my low powered "g/b" router; at least that's my opinion even with a directional yagi.

I'll trade you any time for fixing machinery wireless links and computahs in the King City, CA garlic fields during harvest time. Somehow, I always seem to get stuck downwind of the smell.

Waverider is good hardware and their 900MHz should have no effect on your 2.4Ghz hardware. So much for that theory/guess. No notch in my keyboard this time.

Well, I'm out of great ideas on this one. It's tempting to suggest that there's something wrong with your Belkin F5D7230-4. I have an earlier model that I didn't work very well. I've also had rather bad luck with some (not all) Belkin products. If you can borrow a suitable replacement and see if it makes a difference, it might help assign the blame.

Incidentally, it's easy to guess how far one could use wireless if you know the antenna gain. Assume a laptop has 0dB antenna gain and you can make it to the driveway, about 20meters. If I added 6dBi gain to the laptop antenna, and changed nothing else, I could go twice as far. Range doubles for every 6dBi of antenna gain. 12dBi gain will get me

4 times as far. 18dBi will be 8 times as far. 24dBi will go 16 times as far. With large 24dBi dish, that's 320meters range changing nothing other than the antenna. This is overly simplified as it doesn't include coax and connector losses, but it close enough for estimates.

Look for 5 year old carrying what looks like a large barbeque grill.

My sister live by Gilroy, and I would trade that for the smell of ammonia anytime. :)

Yea, the only thing I don't like is port 23 is kept open, hopefully my ZAlarm firewall is doing it's job.

router;

Belkin, the price was right. With rebates, we'll see if they come back, it was only 20 bucks from Comp(ripoff)USA.

That's good. Easy for my simple brain to understand. When I use netstumbler, I get negative numbers. How can one have a negative dB reading? If you're transmitting, isn't that a signal in positive mWatts?

However, garlic doesn't work with werewolves:

's me at 2am trying to smile and take my own photo.

I'm not sure what's in this stuff:

I suspect one of the secret ingredients is garlic.

Of course, you've heard of spread spectrum. But, would you believe spectrum spread?

Since the FCC has turned spectrum into an auctionable commodity, there's also the Spectrum line of bottled spreads. they have edible organic spectrum spread:

You haven't smelled ammonia until you've worked in a cannery with rotting fish smell. She has it easy in Gilroy. Most of the garlic fields have been converted to housing and industrial tracts. However, King City is miles and miles of garlic. They intentionally hold the Gilroy Garlic Festival well before the actual harvest time.

It shouldn't be a problem on your PC. Just run: netstat -n in an MSDOS window. The "Local Address" column shows all the port numbers that are open. As long as you're not running a telnetd server on port 23, it's not a problem.

We're lucky. We don't have a local CompUSA. Circuit City is the best we can do. They don't carry Belkin. The local Office Max carries Belkin, Linksys, and Dlink to cover everyone's prejudices.

Nope. The "m" in dBm is "milliwatt". The numbers you're seeing are releative to 1.0 milliwatts or 0dBm. If you were talking about power output from a transmitter, then it would be decibels above 1 milliwatt. For example, 100 milliwatts is 100 times more than 1 milliwatt. So, the math is: dBm = 10 * log (ratio) dBm = 10 * log (100) = +20dBm

However, receive signals are usually less than 1 milliwatt, the ratio becames a fraction, and therefore the dBm values are negative. If the receiver hears a signal at 100 microwatts [1], then that's 1/1000th of the 1 milliwatt signal or: dBm = 10 * log (ratio) dBm = 10 * log (1/1000) = -30dBm

[1] Receive signal is usually not described in microwatts but is either converted to dBm as above or expressed in microvolts across a 50 ohm load: 100E-6 watts = (Voltage)^2 / 50 ohms 100E-6 = E^2 / 50 E = 0.7E^-3 = 700 microvolts.

Well, at least you don't have to worry about evil spirits haunting your wireless systems. From:

Garlic: Garlic is another ancient method of fending off evil spirits. Garlic has been used in cultures throughout the world as a healing medicine and natural vitamin. It was thought to have a purification principle much like the metal Silver. People would hang it outside their doorways to keep evil spirits from entering their homes. The ancient societies got a little carried away with Garlic condemning anyone who had an aversion to garlic as a vampire. Garlic was also passed out during church ceremonies so that church official could be sure that no evil spirits were attending.

Pehaps if I hang a clove on my antenna, it will keep evil interference away.

LOL, yeah vampire free..........

server

The only port I see is 1272 1273. But when I go to GRC.COM the 23 shows open. I'll not worry anymore.

That's good, thanks. Is dBm similar to dBi (I think that what I've seen). I was trying to setup a wireless connection with my neighbor but with the evergreen trees and LOS and distance I gave up. Anyway, thought I saw some specs for antennas in dBi.